Field Fitter

Or let the book do it

Fourteen calculators sit in 13.1 — offsets, cut lengths, fractions, conversions, weights, flow, volume, grade, triangles, circumference, expansion, sling loads, pressure and fab layout. Every one of them shows the math underneath, so you can check it by hand.

Sources: The standard named on each chart’s own page; the full list is in 12.11.

A table in this book gives you a number fast. Knowing what kind of number it is — and what beats it — is what keeps it from costing you a joint.

Working the table itself

Find your size down the left. The first column is frozen on the wide tables, so it stays put while the rest scrolls.
Wide tables scroll sideways. If a table looks like it stops at the edge of your screen, drag it left — there are more columns.
Copper numbers are the ones worth noticing. Anywhere a figure is printed in copper it is either the one people use most or the one that breaks the pattern.
Every dimension in this book is in inches unless the column head says otherwise. Millimetres are in 17.4.

What kind of number you are looking at

Kind	What it means and what beats it
Nominal per a standard	Fitting and flange dimensions, pipe walls, thread data. The entry names the standard — B16.9, B16.5, B36.10M and so on. The standard itself is the authority, and real fittings are allowed a tolerance around it.
Computed	Ordinates, trig, conversions, offset constants. These come out of the geometry and they are exact — you can check any of them with the formula printed beside the table.
Typical working figure	Grooved take-outs, olet heights, torque, torch pressures, valve lengths. These vary by maker. The catalogue or the card in the box governs, always.
Common code limit	Hanger spacing (a maximum) and drainage grade (a minimum). Local code governs and it differs by jurisdiction. Where two tables disagree, the tighter one wins.
Safe working load	Rope and rigging. Already divided by the design factor — do not divide it again. The tag on the sling beats every table there is.

What beats this book

Your job spec and drawings, the code or standard the job is built to, and the maker's data for the fitting in your hand all outrank this book. When any of them disagree with a number in this book, they win and the book is wrong for your job.

That is not modesty. A book cannot know your class, your service, your temperature or which shop made the fitting on your rack.

Which of those wins over the others depends on the job, the contract and the jurisdiction — it is not a fixed order. If the spec, the drawing, the code and the maker's data disagree with each other, do not pick one yourself. Stop and ask your foreman or the engineer.

Between two rows

Most of these tables step in whole sizes, half degrees or hundredths. When your number falls between two rows, take the difference between them and split it by how far along you are.

Worked — a tangent between rows You need tan 32.7°. The table has 32° at .6249 and 33° at .6494.
Step per degree: .6494 − .6249 = .0245
You are .7 of the way: .6249 + (.7 × .0245) = .6421
The calculator says .6420. A ten-thousandth apart, on a number you are about to round to the nearest sixteenth anyway.

Interpolating works on anything that changes smoothly — trig, ordinates, conversions. It does not work on fitting dimensions. A 5" Class 150 weld neck is 3.50 through the hub, the same as the 6" — not the 3.25 halfway between the 4" and the 6". Pipe schedules do not interpolate at all.

Round once, at the end

Carry the decimals all the way through the math and convert to a fraction only when you have the final number. Round at three steps in one offset and you will be an eighth out with no idea where it went.

Measure the first one out of every box

Patterns vary between makers, reconditioned fittings drift, and imported fittings may not be to the standard at all. Check the first fitting from each box against the table. If they agree, trust the table for the rest of that box. If they do not, trust the fitting in your hand and write the real number on the lid.

Sources: ASME B16.5, B16.9 and B36.10M for dimensions; makers’ catalogs where a table says so.

Weld pipe is the simplest material in this book to figure and the least forgiving to get wrong. There is no thread to back off and no socket to slide in — the pipe stops at the face of the fitting and the welder closes the gap. Get the number right and it fits. Get it wrong and you cut a new piece.

Everything in this section follows one joint from the print to the finished weld, in the order you actually do it. This page is the vocabulary you need before any of the rest of it makes sense.

Centre to centre: the most common dimension on prints

The print gives you one number: centre to centre. Inside it sit two take-outs, two root gaps and the pipe you actually cut. Learning to see those pieces in one dimension is most of what this section teaches.

The most common measurement in the pipe world is centre to centre (C TO C or CTC), and it is the centreline of one fitting to the centreline of the next. Not the outside of one fitting to the outside of the next. Not face to face. The centre of one fitting to the centre of the next.

It is measured that way because the centreline is the only thing that does not change. Faces move when you swap a long radius elbow for a short one; the point where the two centrelines cross does not care what fitting you hang there. That crossing point is the working point, and it sits out in mid-air where there is no metal at all — which is exactly why you cannot hook a tape on it and why take-outs exist.

Take-out, in detail

Take-out is the distance from the working point to the face of the fitting — the length the fitting occupies along one leg of the dimension. Subtract one at each end of your C to C and what is left is pipe. The working point is where the two centrelines cross — there is no metal there.

Take-out is not the size of the fitting. It is how much of your dimension the fitting eats. Every elbow and tee has one, it is published in a standard, and it is a fixed nominal figure for a given size and pattern — which is what makes the math reliable. (The fitting in your hand can still be off by its tolerance; 1.11h.)

TAKE-OUT = WORKING POINT → FACE OF FITTING

You will also hear it called centre to face or centre to end. Same number, three names. On the job you read it off 1.11, or on a long radius 90 (1" and up) you do 1.5 times the size in your head. The geometry behind it (bend radius times the tangent of half the turn) is worked through in 18.16 if you want it.

The words, and what each one points at

A 12" line called at TOP and the same line called at BOP are more than a foot apart. Read which one the drawing is dimensioning to before you hang anything.

C to C: Centre to centre. Working point to working point. How prints dimension.
Working point: Where two centrelines cross. A point in mid-air with no metal at it.
Take-out: Working point to the face of the fitting. What you subtract.
Face of fitting: The flat, prepped end of an elbow, tee or reducer, where your pipe stops.
Face of pipe: The cut and bevelled end of the pipe itself. On a butt weld joint the two faces sit a gap apart — they never touch.
Face of flange: The gasket surface. Flange dimensions and valve face-to-face figures run to it, and it is what lands against the mating flange.
TOP / BOP: Top of pipe and bottom of pipe — the outside, not the bore. BOP is what sits on the steel, so it is what racks get set to.
Invert: The inside bottom. Drainage grade is set to invert, and it differs from BOP by one wall thickness.
TOS: Top of steel. The beam, not the pipe.
Cut length: The raw piece of pipe, end to end, before it is bevelled. What you write on the cut list.
Root gap: The space between the two faces that the welder needs to get the root in. Usually 1/16" to 1/8".
Bevel: The angle ground or cut on the end of the pipe or fitting so the weld can reach the full wall. Standard is 37-1/2° off square (± 2-1/2°, ASME B16.25), so two bevelled ends make a 75° groove.
Land / root face: The flat strip left at the bore when you bevel — about 1/16".
Spool: Pipe with fittings already welded on, built at the bench and set as one piece.
Field weld: A joint deliberately left open so the spool can be adjusted in place. Marked FW on the iso.

The full trade glossary is 12.9, and the parts of a fitting are drawn and labelled in 19.1.

Why weld pipe has no add-back

The habit that ruins weld pipe

Threaded pipe screws into its fitting and copper slides into a socket, so on both of those you get some length back. Butt weld does not. The pipe stops at the face, nothing goes inside, and nothing comes back.

If you ever catch yourself adding a number back on a butt weld joint, you have carried a habit over from another material. Take-outs come off. That is all.

What you measure and mark with

25 ft tapeOne tape for the whole job, and do not lend it. Two tapes can disagree a sixteenth over ten feet and both be in tolerance. Reading one properly is 19.2.
Wrap-aroundThe single most useful thing in your bags on weld pipe. Squares a line all the way round a pipe, which nothing else will do. Full page at 1.4.
Soapstone and a holderMarks on hot, oily, scaled steel where a marker will not. Keep it sharpened flat, not pointed.
Silver streak or paint penFor marks that have to survive handling. Keep paint off anything about to be welded.
Framing square and a combination squareChecking a face, marking square across, and finding the centre of a pipe end (19.7).
Torpedo level and a 2 ft levelThe torpedo lives in your bags; the 2 ft is the one you trust on a run. Reverse-check both (19.3).
Centre punchA soapstone line disappears the first time somebody handles the pipe. A punch mark does not.
Hi-lo gaugeCheap, small, and the only way to know what the bores are doing once the outsides are lined up.
Contour markerA washer with a soapstone through it. Scribes a fishmouth around anything round, faster than any layout.

The full weld-pipe kit — cutting, bevelling, fit-up and rigging — is 1.10.

The order this section runs in

Measure it (1.2), figure it (1.3), wrap and mark it (1.4), cut it (1.5), prep it (1.6), fit it (1.7), weld it (1.8), and check it again (1.9). If you are new, read them in that order once. After that you will only ever open the one you need.

Sources: ASME B16.9 (butt weld fitting center-to-end), ASME B16.25 (butt weld ends); C to C measuring is common trade practice.

The math is the easy part. Getting a good measurement to run it on is what gets people, because there’s usually nothing at the working point to hook a tape to.

Where the tape actually goes

Three references that exist in the real world, and one — the working point — that does not. Everything you measure in the field is one of the first three plus math.

Measuring off a square end

A square end is the most useful thing on a piece of pipe, because it is the only end you can hook a tape to and trust. Every layout in this section starts from one.

Check it is actually square before you measure anything off it. A wrap-around laid round the end will show you in five seconds — if the edges of the wrap line up with each other but not with the pipe end, that end is out. Full check in 1.6a.
If it is not square, make it square first. Cutting a piece to a perfect dimension off a crooked end gives you a perfectly wrong piece.
Hook the tape on the end and pull your dimension. The hook slides by its own thickness so it reads true both pushing and pulling — that slop is not wear (19.2).
Mark with a wrap line, not a tick. A tick tells you where. A wrap line tells you where and square, and it is the line you are going to cut to.

Burning an inch — optional

You don't have to burn an inch. If your hook is straight and tight, hooking the end is fine, and it is what most fitters do day to day. Burning an inch is just something you can do when you don't trust the hook — it's bent, it's loose, the end won't take it — or on a long or critical pull where you want the hook out of the picture.

How: line the 1" mark up with the end instead of the hook, read the tape, then take 1" off what you read.

It doesn't have to be an inch. You can burn any number you want — 1", 2", 10", whatever lines up easy on the end. It works the same way as long as you know what you burned and take that same amount back off. A round number like 10" makes the math easy: burn 10", read 52-3/8", your measurement is 42-3/8".

If you do burn an inch, these are the two ways it goes wrong:

Forgetting to take it back off. Burn an inch, forget to subtract it, and your piece comes out an inch long — burn 10" and forget, and it's 10" long. Same thing if your partner burned it and never told you. So say it out loud — “burning an inch,” “burning ten” — to whoever is on the other end of the tape.
Not doing it the same way every time. If you burn an inch on one measurement and hook the next one — or burn 1" one time and 2" the next — your numbers won't match and you won't know which is right. Pick one way and stick with it for the whole run.

Tape measure laid along galvanized pipe with the 12 inch mark on a wrap line drawn round the pipe, and the next length ticked further along. — **Burning a foot** on sleeve stock. The 12" mark sits on the last line, so take 12" off whatever the tape reads. When you mark several pieces off one stick before cutting, add the width of the blade between each one — this crew added 1/8" for the cut-off saw — or every piece after the first comes out short. Kerf by tool is in 1.5; the whole sleeve job is 9.3.

Taking a field weld measurement

The common job: two spools are hung, there is a gap between them, and you have to make the piece that closes it.

Get both ends supported and where they will finally sit. A spool resting on a come-along is not where it will be tomorrow.
Measure face to face — the actual gap between the two prepped ends, not centre to centre. This is the one place in weld pipe where face-to-face is the number you want.
Take off the two root gaps the welder is going to hold. Your piece has to be shorter than the opening by two gaps.
Take it in two places, 90° apart around the pipe, and take the same measurement twice. If the two readings differ, something is out of square or out of line — find out which before you cut.
Write it on the pipe along with the line number and which end is which.

FIELD PIECE = FACE TO FACE − GAP_A − GAP_B

Worked — closing an opening in 6" Face to face between the two prepped ends: 41-3/8"
Welder is holding 1/8" gaps: 41-3/8 − 1/8 − 1/8 = 41-1/8"
That is the finished length: 41-1/8". On a closing piece between two fixed ends, cut it long and trim to that number (see below).

Cut the closing piece long

On a field weld that has to close between two fixed ends, leave 1/2" to 1" on it and trim to fit. Everything upstream of that joint has been accumulating error all day — hanger positions, weld shrink, a spool that pulled. The closing piece is where all of it lands.

A piece cut an inch long takes five minutes to trim. A piece cut a quarter short is scrap.

Habits that keep field measurements honest

Pull everything from one benchmark, not from the last thing you set. Chained measurements stack their errors, and on a long rack that is how the far end ends up two inches out with every individual measurement correct. String lines and how to use them: 19.5.
Measure it twice, and the second time act like you have not seen the first number. Reading what you expect to read is the commonest error in the trade.
Both people say the number out loud. "Forty-one and an eighth" beats a thumbs-up across a bay every time.
Photograph anything you are about to cover up, with a tape in the shot.
Check the print against the field before you cut, not after. When they disagree, that is a foreman question — 12.7.

The four field measurementsTape hooked on a square end, tape butted to a flange face, tape to a fitting face with the take-out being added on a note, and a two-man pull across a bay with both men reading. PHOTO

From the Trade

“Simple run: measure it all up front. Tight or complex: piece by piece.” — Seth Edstrom. His full tip: 21.3.

Sources: Common trade practice; take-outs from ASME B16.9.

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The fitting eats length, then the pipe screws back into it and gives some of that length back. The difference is called the net, and it's the only number you need.

Screwed pipe is the one place where the fitting gives some of its take-out back. Subtract the take-out, add back the thread engagement — the net is all that comes off the pipe.

CUT = CENTER-TO-CENTER − NET_A − NET_B

NET = TAKE-OUT − THREAD ENGAGEMENT

Worked — 1" black iron, 90 to 90, 36" C to C 1" 90: take-out 1.50", engagement 0.69" → net 0.81"
36 − 0.81 − 0.81 = 34.38" = 34-3/8"
Cut that length, then thread both ends.

Learn two numbers and you're free

Whatever size you run most, memorize its net 90 and net 45. On 2" it's 1-1/2" and 15/16". On 1" it's 13/16" and 7/16". Then you cut straight off the print without touching a calculator.

Cut length is not thread length

The cut length above is the pipe, raw, before threading. Threading doesn't shorten it — the die cuts into the wall, not off the end. Cut, then thread.

Sources: ASME B16.3 (malleable iron fittings); ASME B1.20.1 (NPT threads).

150# malleable iron. The NET take-out comes first — that's what you subtract. The gross take-out, centre to the end of the fitting, is on the far right.

Take-outs are the ASME B16.3 centre-to-end figures. Engagement is the trade's wrench-tight make-up, not the B1.20.1 hand-tight figure, so NET is what a fitting actually eats in the field. Patterns vary between makers — check the first fitting out of every box.

Size	NET 90	NET 45	Engage	Gross 90	Gross 45
1/8"	0.44	—	0.25	0.69	—
1/4"	0.43	0.35	0.38	0.81	0.73
3/8"	0.57	0.42	0.38	0.95	0.80
1/2"	0.62	0.38	0.50	1.12	0.88
3/4"	0.75	0.42	0.56	1.31	0.98
1"	0.81	0.43	0.69	1.50	1.12
1-1/4"	1.06	0.60	0.69	1.75	1.29
1-1/2"	1.25	0.74	0.69	1.94	1.43
2"	1.50	0.93	0.75	2.25	1.68
2-1/2"	1.76	1.01	0.94	2.70	1.95
3"	2.08	1.17	1.00	3.08	2.17
4"	2.67	1.49	1.12	3.79	2.61

A tee take-out equals the 90 of the same size — run and branch both. Use the same net.

Couplings

A coupling has no centerline to work from, so the take-out idea doesn't apply. Work it out from lengths instead.

ASSEMBLED = PIPE₁ + PIPE₂ + COUPLING LENGTH − (2 × ENGAGEMENT)

In practice

A standard coupling adds roughly 1/4" to 3/8" over the two pipe lengths on small sizes. Thread a scrap into one and measure it once — then you know for that box.

Unions

Union dimensions vary more than any other threaded fitting — pattern, class and manufacturer all change them. Measure the one in your hand. A union is an in-line fitting, so measure it face to face — end to end, made up.

Typical ground-joint union, end to end 1/2" ~1-3/4" 3/4" ~1-15/16" 1" ~2-3/16"
1-1/4" ~2-1/2" 1-1/2" ~2-5/8" 2" ~3"
Verify before you cut a run around one.

Reading the table — 1/2" threaded 90 90 take-out 1.12, engagement 0.50, so NET 0.62.
Centre to centre 24" between two 1/2" 90s:
24 − 0.62 − 0.62 = 22.76" of pipe, measured end to end before threading.

Why the net, not the take-out The fitting eats 1.12" — but the pipe screws 0.50" back into it.
Subtract the whole take-out and you cut every piece an inch short over two fittings.
The net is the only number that comes off the tape.

Sources: ASME B16.3 center-to-end; wrench-tight engagement is common trade practice (B1.20.1 gives hand-tight).

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Copper take-out already runs to the bottom of the socket — the point where the pipe stops. Subtract it once, from each end. There is no second "socket depth" step.

Copper take-out already runs to the bottom of the socket, the point where the pipe stops. There is no separate socket-depth step like screwed pipe's thread engagement — subtract the take-out once, from each end.

CUT = CENTER-TO-CENTER − TAKE-OUT_A − TAKE-OUT_B

TAKE-OUTS VARY BY MAKER — CHECK THE FIRST FITTING (3.2).

Worked — 1/2" copper, 90 to 90, 42" C to C 1/2" 90 take-out: 0.50", to the bottom of the socket.
42 − 0.50 − 0.50 = 41" of tube, cut and reamed before you solder.

Don't subtract the socket depth again

The take-out in 3.2 already runs to the bottom of the socket — that is the whole net. Subtract it once, on 90s and 45s alike, and stop there. Subtracting a separate socket depth on top of it is the classic copper mistake, and it cuts every piece short by two socket depths — 1" on 1/2" tube, over 4" on 4".

Always bottom the pipe

All of this assumes the pipe goes all the way into the socket. If it doesn't bottom, your net is wrong and the joint is weak. Push it home and give it a quarter turn.

Sources: Typical take-outs for ASME B16.22 wrot copper fittings; the maker’s fitting governs.

Wrot copper fittings. Each take-out below already runs to the bottom of the socket — that's the net, full stop. These are typical figures, and wrot copper varies more between makers than any other fitting in this book — a quarter inch or more on the same size is normal, and short-radius (close rough) ells run shorter than this table. Check the first fitting out of the box before you cut a run: a framing square on a 90, tracing on anything else (1.11h).

Size	90 take-out	45 take-out
3/8"	0.38	0.19
1/2"	0.50	0.25
3/4"	0.75	0.31
1"	0.88	0.38
1-1/4"	1.00	0.44
1-1/2"	1.25	0.50
2"	1.50	0.62
2-1/2"	1.75	0.81
3"	2.00	0.94
4"	2.50	1.12

A tee runs about the same as the 90 of its size. Cast fittings run slightly different — measure the first one.

Fitting-to-fitting

Two fittings soldered straight together with no pipe between them still need a piece of pipe inside — that's what a close nipple's job is in copper too. Cut a stub equal to both socket depths and solder both at once.

Reading the table — 1/2" copper 90 Take-out 0.50", to the bottom of the socket.
Centre to centre 36" between two 1/2" 90s:
36 − 0.50 − 0.50 = 35" of tube, cut and reamed before you solder.

Reading the table — 3/4" copper 45 Take-out 0.31", to the bottom of the socket.
20" C to C between two 3/4" 45s:
20 − 0.31 − 0.31 = 19.38" = 19-3/8".

Sources: Typical figures for ASME B16.22 wrot copper fittings; makers vary.

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Same idea as screw pipe — take-out minus what you get back — except here you measure both numbers yourself. Plastic fitting dimensions vary between manufacturers far more than metal does, so you verify them instead of trusting a table.

Plastic fittings have a deep socket, and the pipe bottoms out in it. That depth comes back to you: subtract the two take-outs, then add the two socket depths. Dry-fit first — a cemented joint is not coming apart. On 4" schedule 40 the socket is a full 2" deep. Forget to add both back and every piece comes out a full 4" short.

CUT = CENTER-TO-CENTER − NET_A − NET_B

NET = TAKE-OUT − SOCKET DEPTH

Finding both numbers in ten seconds

On a 90, lay the fitting on a flat bench against a framing square. Butt one face to the blade and measure from the blade to the center of the other opening — that's the take-out. A 45 won't read true that way; trace it instead (1.11h). Then measure the socket depth inside the fitting, from the hub face to the shoulder, or read it off the table below. Write both on the box in marker and you're set for the whole job.

Socket depth — PVC Sch 40, nominal

Size	Socket	Size	Socket
1/2"	0.69	2"	1.16
3/4"	0.72	2-1/2"	1.75
1"	0.88	3"	1.88
1-1/4"	0.94	4"	2.00
1-1/2"	1.09	6"	3.00

Dry fit sits shallow

A dry-fit socket only takes the pipe part way in. A good dry fit goes in a third to two-thirds of the way; with cement on it the pipe goes to the bottom, because the cement softens the material. Measure your socket depth in the fitting itself, not from a dry fit, and know the joint will close up a little more when you glue it.

Sources: ASTM D2466 (Sch 40 PVC fittings); Spears fitting dimensions. Makers vary.

Schedule 40 and 80 PVC and CPVC use the same OD as steel pipe of the same nominal size, which is why the fittings look familiar. Tan CTS CPVC is copper tube size, not pipe size. The pressure ratings do not behave like steel at all.

Size	OD	Sch 40 wall	Sch 80 wall	Sch 40 psi
1/2"	0.840	.109	.147	600
3/4"	1.050	.113	.154	480
1"	1.315	.133	.179	450
1-1/4"	1.660	.140	.191	370
1-1/2"	1.900	.145	.200	330
2"	2.375	.154	.218	280
2-1/2"	2.875	.203	.276	300
3"	3.500	.216	.300	260
4"	4.500	.237	.337	220
6"	6.625	.280	.432	180
8"	8.625	.322	.500	160

Pressure ratings are for water at 73°F. They drop hard with temperature.

Temperature derating — this is the whole story on plastic

PVC at 110°F holds about half its rated pressure. At 140°F it's down around 22%, and PVC isn't rated above 140°F at all. CPVC carries to 200°F but is also derated as it goes up. A 280 psi 2" pipe is not a 280 psi pipe in a hot mechanical room.

Never compressed air in PVC

PVC fails by shattering, and compressed air stores enough energy to turn the pipe into shrapnel. OSHA has warned against it since its 1988 hazard bulletin, and PVC makers prohibit it. Don't do it, and don't pneumatic-test a PVC system.

PVC: Cold water, drainage, vent. To 140°F. White or grey.
CPVC: Hot water to 200°F. Tan (CTS) or light grey (Sch 80).
Sch 80: Grey, heavier wall, higher pressure. The only plastic you should ever thread.

Schedule 40 next to schedule 80Two 2" PVC ends sawn square and stood side by side so the wall difference is obvious, with the printed line on each barrel readable in the shot. PHOTO

Sources: ASTM D1785 (PVC Sch 40/80), F441 (CPVC Sch 40/80), D2846 (CTS CPVC); pressure derating from makers’ published data.

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Grooved works like weld pipe for the math — take-outs only, no add-back. The pipe ends sit inside the coupling housing a set gap apart, and the gasket bridges them.

CUT = CENTER-TO-CENTER − TAKE-OUT_A − TAKE-OUT_B − THE COUPLING GAPS

Take-outs are manufacturer-specific

Victaulic®, Anvil, Shurjoint and the rest all publish their own dimensions and they are not the same as butt weld take-outs. The catalog for the brand on your job is the authority. Don't substitute a B16.9 number.

Get the numbers once, on day one

Pull the take-outs for the sizes you're running off the manufacturer's sheet, write them on a card, tape it inside your toolbox lid. Grooved jobs run the same handful of sizes for weeks.

Coupling gap

A flexible coupling is designed with a gap between the pipe ends — that gap is what lets the joint move and it is part of the design, not sloppiness. A rigid coupling clamps the ends so they cannot move — there is still a small gap between them. The allowable gap range for both is on the maker's data sheet. Running the gap at the wide end of the range across a long run adds up to real length, so be consistent.

Worked — laying out a grooved run Pipe is cut to C to C minus both take-outs and the coupling gaps, the same way a welder’s root gap comes off.
Forget the gaps and a long straight run of ten couplings, each holding 1/8", comes out 1-1/4" too long. Take them off every cut, or make the last piece adjustable.

A groove and the coupling that lands on itPipe end with the groove cut, a groove gauge sitting in it, and the coupling and gasket laid out beside it unassembled so the parts can be named. PHOTO

Sources: Typical grooved fitting dimensions; the maker’s catalog governs (Victaulic, Anvil, Shurjoint and others).

Roll groove: Cold-formed with rollers. No metal removed, so the wall stays full thickness. Standard on Sch 10 and Sch 40.
Cut groove: Metal machined out. Only on heavier wall — it takes material away.

The end prep that matters

Square within about .030". An out-of-square end tips the gasket and it leaks.
No flare. Roll grooving raises a flare at the pipe end. Knock it down or the gasket rides over it going in.
Deburr inside and out. The gasket lip drags over that edge.
Gasket seat clean and smooth — that's the band between the pipe end and the groove. No paint, no scale, no weld spatter, no deep scratches running around it.
Groove depth and width gauged on the first joint off each roll set, and spot-checked after. Rollers wear and drift.
Don't groove over a weld seam if you can avoid it, and never groove a bell, a swage or a previously grooved end.

Wall thickness and groove type must match

Cut-grooving thin wall pipe removes wall it doesn't have and the pipe fails under pressure. Check the manufacturer's table for which groove goes on which schedule before you set the machine up.

Field cut ends

Abrasive saw or a roll cutter, square. A torch-cut end cannot be grooved — the heat-affected metal won't form right and the surface will never seal.

A good roll grooveFlare knocked down, gasket seat clean and unmarked, groove gauge sat in the groove. PHOTO

Sources: AWWA C606 (grooved joints); the groover maker’s instructions.

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Drainage pipe. Heavy, quiet, and it lasts — which is why it's still specified for soil and waste stacks in commercial buildings long after plastic took over everywhere else.

Two systems that look alike on a print. Hub and spigot needs a bell on one end and depends on the gasket; no-hub is plain-end pipe and depends entirely on the coupling torque. No-hub bands are not hand-tight items — the figure is stamped on the shield. Plain ends, square cuts, and the shield does the work.

No-hub: Plain ends, joined with shielded couplings. What you'll run most. Sizes 1-1/2" through 15".
Hub and spigot: Bell on one end, joined with a compression gasket (or, on old work, lead and oakum).
Service weight: Standard wall.
Extra heavy: Thicker wall, used underground and where it's specified.

Laying out cast iron

There's no take-out table the way there is for pressure fittings — you work from the fitting's laying length, which is in CISPI 301's fitting tables and the maker's catalog, and cast into most fittings. Measure the one in your hand the same way you'd measure a plastic fitting: against a square on a 1/4 bend, traced on anything else (1.11h).

CUT = C TO C − LAYING LENGTH_A − LAYING LENGTH_B

Grade first, always

Cast iron is drainage. Every horizontal run is pitched, and the pitch governs the layout before any dimension does. See 7.7 for the fall math — at least 1/4" per foot on 2-1/2" and smaller, at least 1/8" per foot on 3" through 6".

Sources: CISPI 301 (no-hub pipe), ASTM A74 (hub and spigot), ASTM A888; CISPI 310 (no-hub couplings).

Cutting

Snap cutter — chain around the pipe, squeeze, clean break. Fast and quiet. Support both sides so the drop doesn't bind.
Abrasive saw — cleaner and squarer, and the easiest on extra heavy (a snap cutter rated for it works too). Dusty, so respirator and eye protection.
Square ends matter — the coupling gasket seals on the outside of the pipe right at the end. A chewed or angled break won't seal.
Never cut near a hub or a fitting — the wall thickness changes there and it'll shatter wrong.

No-hub couplings

Slide the shield onto one pipe. Push the gasket onto the other pipe end until the end seats against the gasket's center stop.
Bring the second pipe (or fitting) into the gasket until it seats against the center stop from the other side. Both ends home, not one.
Slide the shield over the gasket and center it.
Tighten the clamp bands alternately to the torque marked on the coupling.

STANDARD NO-HUB: 60 IN-LB | HEAVY DUTY: 80 IN-LB

Use a torque wrench, and read the coupling

These are inch-pounds, not foot-pounds. 60 in-lb is 5 ft-lb — barely anything. Run it up with an impact and you'll strip the band or crush the gasket. Every coupling has its torque stamped on the shield; that number wins over this page.

Hub and spigot

Compression gasket into the hub, lubricate, then drive the spigot home with a puller or a wedge. It takes real force — that's normal.
Lead and oakum is repair work on existing systems. Oakum packed tight, molten lead poured, then caulked. Don't pour lead into a wet joint — it will explode.

Snap cutter and torque wrenchChain set on a 4" cast iron run ready to squeeze, then a torque wrench on a no-hub band with the stamped figure visible on the shield. PHOTO

Sources: CISPI 310 and ASTM C1277 (couplings), ASTM C564 (gaskets); the cutter maker’s instructions.

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Every offset, every brace and every grade problem is a right triangle. Learn this one shape and the rest is bookkeeping.

Taught from scratch

This page is the quick version. The sides are named one at a time in 18.8, the three ratios in 18.10, and solving the whole triangle from one side and one angle in 18.12.

The copper side is always the one you cut. The other two tell you whether it fits where you are putting it.

c = √(a² + b²)

What the sides are called on the job

Opposite: the offset
Adjacent: the run
Hypotenuse: the travel

Worked Offset 14", run 9"
√(196 + 81) = √277 = 16.64" = 16-5/8"

One shape, every problem

Step through it

Sources: Math worked out for this book; check it with the formulas shown.

The full table

Stock fitting angles only. Every half degree from 0 to 90, with cotangents, is 17.8; what the columns mean is 18.10.

sin = OPP÷HYP cos = ADJ÷HYP tan = OPP÷ADJ

Angle	sin	cos	tan
11-1/4°	.1951	.9808	.1989
15°	.2588	.9659	.2679
22-1/2°	.3827	.9239	.4142
30°	.5000	.8660	.5774
45°	.7071	.7071	1.0000
60°	.8660	.5000	1.7321
67-1/2°	.9239	.3827	2.4142
72°	.9511	.3090	3.0777

Finding an unknown angle

Divide, then read the table backwards. Offset 12", run 20" → tan = .600, which sits between 30° and 45° — about 31°. If it isn't a stock fitting angle you roll the fitting or re-route. Don't make a 45 do a 31.

All the formulas for solving a triangle are in 17.7.

Using the table — a 30° offset Look up 30°: sin .5000, cos .8660, tan .5774.
Offset is 14". Travel = 14 ÷ sin 30 = 14 ÷ .5000 = 28.00"
Run = 14 ÷ tan 30 = 14 ÷ .5774 = 24.25"
Divide the offset by sin for the travel and by tan for the run; multiply to go back.

Sources: Computed for this book.

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The line has to move over. You put in two fittings of the same angle with a sloped piece between them. That's an offset, and it has exactly three numbers.

The travel is the piece you cut. The offset and the run tell you whether it fits where you're putting it.

Offset: How far the line moves over. You usually know this from the print or the tape.
Travel: The sloped piece, center of fitting to center of fitting. This is what you're solving for.
Run: How far forward the line goes while it's moving over. Check this against your space.

Why the run matters

Everybody solves for travel and forgets the run. The run is what puts your fitting in the middle of a hanger or through a beam. Check it before you cut.

The offset math is the same for every material. Only the take-outs change — go to your material's section for those.

Sources: Math worked out for this book; check it with the formulas shown.

Three steps. That's the whole thing.

Taught from scratch

The same three steps, worked slowly with the reasons, are 18.17. The multipliers here come from the ratios in 18.10.

The whole job in three steps. You measure one thing — the offset — and the constant does the rest. Take out the two fitting take-outs (and the two root gaps, if your welder holds them — 18.14) and what is left is the piece you cut. At 45° the run equals the offset, which tells you where the far end lands.

Measure the offset — how far the line has to move.
Travel = offset × constant for your fitting angle.
Cut = travel − take-outs — using your material's rule.

45°: TRAVEL = OFFSET × 1.414

Worked — 2" weld pipe 18" offset, 45°, take-out 1.38 each end
Travel = 18 × 1.4142 = 25.46" = 25-7/16" C to C
Cut = 25.46 − 1.38 − 1.38 = 22.70" = 22-11/16"

A 45° offset, start to finish

Step through it

Same offset, 2" screw pipe Travel = 25.46" C to C, same as above
2" threaded 45 net = 0.93"
Cut = 25.46 − 0.93 − 0.93 = 23.60" = 23-5/8"

At 45° the run equals the offset

18" offset means the line also moves 18" forward. That one fact saves you a calculation every single time.

Sources: Math worked out for this book; check it with the formulas shown.

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Common maximums for water service. Your code and spec govern — fire protection, gas and steam all have their own rules.

Spacing is what keeps a line from sagging between supports — and sag is what breaks pitch on a drain and pockets condensate on steam. The tables differ by material because stiffness does: the same span that is fine on 2" steel will belly on 2" CPVC. Steel spans furthest. Copper needs closer. Plastic needs closest of all, and closer again when it is hot. Every material has its own table — use the one for what you are actually hanging. A hanger at every change of direction and every concentrated load (valve, strainer, flange) no matter what the table says.

Size	Steel SP-58	Copper SP-58	PVC IPC	CPVC hot	Rod SP-58
1/2"	7 ft	5 ft	4 ft	3 ft	3/8"
3/4"	7 ft	5 ft	4 ft	3 ft	3/8"
1"	7 ft	6 ft	4 ft	3 ft	3/8"
1-1/4"	7 ft	7 ft	4 ft	3 ft	3/8"
1-1/2"	9 ft	8 ft	4 ft	3 ft	3/8"
2"	10 ft	8 ft	4 ft	3 ft	3/8"
2-1/2"	11 ft	9 ft	4 ft	4 ft	1/2"
3"	12 ft	10 ft	4 ft	4 ft	1/2"
4"	14 ft	12 ft	4 ft	4 ft	5/8"
6"	17 ft	14 ft	4 ft	4 ft	3/4"
8"	19 ft	16 ft	4 ft	—	7/8"
10"	22 ft	18 ft	—	—	7/8"
12"	23 ft	19 ft	—	—	7/8"

Steel and copper: MSS SP-58, water service (ASME B31.1 Table 121.5 gives the same steel spans). PVC: IPC Table 308.5 — 4 ft at every size; the maker's table allows more when cold, much less when hot. CPVC hot: typical for hot-water CPVC; spans shrink as the temperature climbs, so the maker's temperature table governs (IPC allows 3 ft to 1" and 4 ft above for ordinary service). Rod: MSS SP-58 minimum for one rod on steel pipe. Plumbing jobs: the IPC and UPC set their own limits, tighter than SP-58 at some sizes — see the box below. The code on the permit governs.

Cast iron: Every joint, 5 ft max — or 10 ft for 10-ft lengths with a hanger at every joint.
PEX: 32" max at 1" and smaller, 4 ft at 1-1/4" and up (IPC Table 308.5). Hot runs sag between hangers — continuous support channel keeps them straight.
Glass / lined: Per the manufacturer, always closer than you'd think.

The plumbing code has its own table

The steel and copper columns are MSS SP-58 mechanical-piping practice. Where the plumbing code applies, IPC Table 308.5 sets its own limits: PVC 4 ft at every size, copper tube 6 ft at 1-1/4" and smaller and 10 ft at 1-1/2" and up, steel pipe 12 ft. Which one is tighter depends on the size — the code from 4" up and on 1-1/4" copper; SP-58 on steel under 3" and on copper 1/2"–3/4" and 1-1/2"–2-1/2". UPC Table 313.3 is different again: copper 6 ft at 1-1/2" and smaller and 10 ft at 2" and up, steel 10 ft at 3/4" and smaller and 12 ft at 1" and up.

Use the tighter of the two at every size. Hot lines go closer again. Find out which code your job is built to before you set the first hanger.

Rules that beat the table

Hang within a couple of feet of every change in direction.
Hang at every concentrated load — valve, flange pair, strainer, meter. The table assumes straight pipe with nothing on it.
Never hang off another trade's work — no duct, no tray, no conduit, no sprinkler. Structure only.
Dielectric isolation where copper touches steel.
Shield or saddle at every hanger on insulated line.

Leave them a flat loose

Don't final the hangers until the line is complete and tested. Tightening as you go pulls a line out of grade and out of line.

Sources: MSS SP-58 (pipe hangers); ASME B31.1 (suggested support spacing); IPC and UPC hanger tables. Your spec and local code govern.

Clevis: The standard workhorse for a single line off a rod.
Trapeze: A channel across two rods. Carries several lines at once and lets you space them properly.
Roller: Lets the pipe move axially. Hot lines that grow.
Riser clamp: Carries a vertical line at the floor. Every floor on a stack.
Spring hanger: Where the pipe moves vertically and still has to be supported through the movement.
Anchor: Holds the pipe rigidly. Not a hanger. Decides where expansion goes.
Guide: Holds the line laterally but lets it slide. Works with the anchor.

Anchors and guides are engineered

They're on the drawing in a specific place for a specific reason. Moving one because it's inconvenient changes where all the expansion goes and can load a nozzle or a building member that was never meant to see it. If it can't go where it's drawn, that's a question for the engineer.

Getting it right

Rod size from the table in 9.1, and check the attachment is rated for the load too — the rod is often not the weak link.
Insulated lines: shield at minimum, a proper saddle on anything heavy or cold. A clevis on bare insulation crushes it and you get condensation and rot.
Cold lines get a vapor-barrier-safe support — an insulated pipe support block, not a bare clamp that bridges the barrier.
Leave room to insulate. Nothing is more frustrating than a perfectly hung line the insulators can't get around.

The hanger familyClevis, roller, trapeze and riser clamp, plus an insulated line on a shield and one crushing its insulation. PHOTO

Sources: MSS SP-58 (hanger types); anchors and guides are placed by the engineer.

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Rigging is the part of this trade that kills people fastest, and it doesn't give second chances. This section gives you basic to intermediate knowledge, so you understand what a rig is doing and why, and you can tell when one looks wrong. It does not qualify you to rig anything.

Read this before any page in this section

Field Fitter is a reference, not training, and not a lift plan. Rigging and signalling must be done by people who are trained and qualified for that work, and certified wherever your employer, the site owner, the state or the job requires it.

Nothing in this section authorises you to rig, signal or direct a lift. Pipelogic LLC and Field Fitter take no responsibility for any lift, rig, sling, hitch, load or outcome. That responsibility sits with the qualified rigger, the lift plan, your employer's program and the equipment manufacturer. Where any of those say something different from this book, they win, every time.

Using this section means you accept that. The full disclaimer is in 20.8.

Qualified and certified are not the same thing

Qualified: OSHA's word. It means someone who has shown they can solve problems in that work, through a recognised degree, certificate or professional standing, or through extensive knowledge, training and experience (29 CFR 1926.32(m)). Your employer decides who is qualified and should be able to show how they decided.
Certified: You passed a third-party written and practical exam and hold a card, for example NCCCO Rigger Level I or Level II, NCCCO Signalperson, or the NCCER rigger and signal person credentials. Many sites, owners and union agreements require the card, whatever OSHA's minimum is.

When the rules say it has to be a qualified person

These are OSHA's construction crane rules (29 CFR 1926 Subpart CC), in general terms:

Hooking, unhooking or guiding a load, or making the first connection to a structure, while anyone is in the fall zone: the load has to be rigged by a qualified rigger (1926.1425).
Rigging during crane assembly and disassembly: qualified rigger (1926.1404).
Giving signals to a crane operator: a qualified signal person, with the qualification documented (1926.1428).
Slings and rigging hardware themselves: 1926.251 in construction, 1910.184 in general industry, with ASME B30.9 (slings), B30.10 (hooks), B30.16 (chain falls), B30.21 (come-alongs), B30.20 (below-the-hook devices) and B30.26 (hardware) behind them.

Rules are revised. These are summaries as of this edition, not the text of the rule. Your safety department has the current version.

What this section is good for

Understanding why the rigger set it up that way.
Checking a rig, a sling tag or a sling angle before you stand anywhere near it.
Knowing which questions to ask, and when to say stop.
Studying for a rigging card, alongside a real course.

It is not good for planning a lift, rating an attachment point, deciding a lift isn't critical, or talking yourself into a pick you aren't sure of.

Anybody can stop a lift

The crane operator has to obey a stop or emergency stop signal no matter who gives it (1926.1417). If something looks wrong, stop it. Nobody who knows rigging will hold it against you. The people who get hurt are the ones who saw it and said nothing.

Get the card anyway

Even where it isn't required, a rigging and signal person card is worth having. Ask your employer, your hall or your apprenticeship about NCCCO Rigger Level I and Signalperson, or the NCCER modules. The Test Prep section covers the NCCER pipefitting tests, rigging questions included (24.9), but not the NCCCO exams. For those, get the candidate handbook from NCCCO.

Sources: ASME B30 series; OSHA 29 CFR 1926 Subpart CC.

The same questions before every lift, big or small. If you can't answer one of them, the pick waits until you can.

Who is in charge? Who is the qualified rigger for this lift, and who is the one signal person? Name them out loud.
What does it weigh? A number, not "about a ton". Include the rigging, and any water or product still inside (25.7).
Where is the centre of gravity? Is the hook going to be right over it (25.8)?
Is everything rated for it, in this hitch and at this angle? Tags readable, sling angle worked out (25.3), choker and wrap derating applied (25.5).
Inspected today, in your hands? Slings, shackles, hooks and latches (25.6).
What is it hanging from? Is the crane, hoist, beam clamp, trolley or structure rated, and did somebody qualified say so?
Softeners on every edge?
What's overhead? Power lines, other trades, lights, sprinkler pipe (25.18).
Where does it land? Is the landing spot clear, with dunnage or blocking ready?
Where are the people? Is the fall zone barricaded, tag lines on, nobody under it or between it and anything solid?
Are the signals agreed? Hand or radio? Radio checked? Everybody knows the stop signal?
Weather? Is the wind under the site limit? Any lightning in the area?
Trial lift. Take it up an inch, stop and look, before it goes anywhere.

If it's a critical lift, this isn't enough

A lift near the crane's capacity, a lift with two cranes or two hoists, a lift over people or live lines, or anything unusual needs a written lift plan from a qualified person. This list doesn't replace it (25.11).

Sources: ASME B30.9; OSHA 29 CFR 1926.251; your lift plan governs.

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A flange is described by four numbers, and the bolt circle is the one that decides whether it mates. Holes always straddle the vertical centreline, never sit on it. Check the class stamped on the rim before you order the gasket — a 300 flange on a 150 line will not bolt up.

Size	OD	Bolt circle	No.	Dia	Stud
1/2"	3.50	2.38	4	1/2"	2-1/4"
3/4"	3.88	2.75	4	1/2"	2-1/2"
1"	4.25	3.12	4	1/2"	2-1/2"
1-1/4"	4.62	3.50	4	1/2"	2-3/4"
1-1/2"	5.00	3.88	4	1/2"	2-3/4"
2"	6.00	4.75	4	5/8"	3-1/4"
2-1/2"	7.00	5.50	4	5/8"	3-1/2"
3"	7.50	6.00	4	5/8"	3-1/2"
4"	9.00	7.50	8	5/8"	3-1/2"
5"	10.00	8.50	8	3/4"	3-3/4"
6"	11.00	9.50	8	3/4"	4"
8"	13.50	11.75	8	3/4"	4-1/4"
10"	16.00	14.25	12	7/8"	4-1/2"
12"	19.00	17.00	12	7/8"	4-3/4"
14"	21.00	18.75	12	1"	5-1/4"
16"	23.50	21.25	16	1"	5-1/4"
18"	25.00	22.75	16	1-1/8"	5-3/4"
20"	27.50	25.00	20	1-1/8"	6-1/4"
24"	32.00	29.50	20	1-1/4"	6-3/4"

Flange dimensions per ASME B16.5. Stud lengths are the usual B16.5 chart for raised face — about a 1/8" gasket, points not counted, rounded up to the next 1/4" (the formula below lands within 1/4" of the chart). Confirm against the actual flanges on your job.

STUD = 2 × FLANGE THK + GASKET + 2 × NUT + 1/4"

Round up to the next 1/4". You want the stud right through each nut with a thread or two showing — never short of flush. (B31.3 accepts one thread short at most.)

Reading the table — 6" class 150 OD 11.00", bolt circle 9.50", 8 holes, 3/4" bolts.
Chord between two adjacent holes = 9.50 × sin(180 ÷ 8) = 9.50 × .3827 = 3.64" = 3-5/8"
Set your dividers there and step it round. The eighth step should land back on your first mark; if it misses, split the error and step it again.

Sources: ASME B16.5 (Class 150).

Nominal per ASME B16.5. The standard governs.

Size	OD	Bolt circle	No.	Dia
1/2"	3.75	2.62	4	1/2"
3/4"	4.62	3.25	4	5/8"
1"	4.88	3.50	4	5/8"
1-1/4"	5.25	3.88	4	5/8"
1-1/2"	6.12	4.50	4	3/4"
2"	6.50	5.00	8	5/8"
2-1/2"	7.50	5.88	8	3/4"
3"	8.25	6.62	8	3/4"
4"	10.00	7.88	8	3/4"
6"	12.50	10.62	12	3/4"
8"	15.00	13.00	12	7/8"
10"	17.50	15.25	16	1"
12"	20.50	17.75	16	1-1/8"

Telling them apart in a rack

Same nominal size, a 300# flange is bigger in OD, thicker, and often has more or bigger bolts. Check the marking stamped on the rim — class, material and size are all there.

Why you cannot mix classes 6" class 150: OD 11.00, bolt circle 9.50, 8 holes at 3/4".
6" class 300: OD 12.50, bolt circle 10.62, 12 holes at 3/4".
Different circle, different count. They will not bolt together and no amount of persuasion will change it — check the rim before you hang either one.

Sources: ASME B16.5 (Class 300).

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Water is nearly incompressible, which is what makes a hydro safe — but only if all the air is out. Vent every high point until it runs solid water, drain from the low point, and put the gauge where you can read it from a safe spot. Fill from the bottom, vent from the top, and do not put the gauge where you cannot read it without standing under the line. Trapped air is what turns a water test into an air test.

Step through a hydro

Step through it

Simplified drawing of how it works, not any one brand; the numbers are examples.

Hydro first, always, if you have the choice

Water stores almost no energy. A failure under hydrostatic test is a mess. A failure under pneumatic test kills people.

Walk the system and confirm every joint is complete, every hanger is in, and every support will carry the water weight.
Isolate or remove what can't take it — gauges, relief valves, control valves, expansion tanks, pump seals, and anything rated below the test pressure. Write down every single one as you pull it.
Open every high-point vent and confirm it's actually open.
Fill slowly from the low point and let the air push out ahead of the water.
Close each vent once it runs solid water, with no air spitting. Close it at the first drop and you trap air.
Bring pressure up in stages, walking the line at each stage.
Hold for the required time and record it.
Depressurize slowly, then drain completely.
Put back everything you took out, off the list you wrote, and have somebody else check it against the list.

The test pressure is not yours to pick

The code and the job spec set the test pressure and the hold time, and they are written on the test package before anybody opens a valve. Different codes, services and temperatures give different answers, and some lines get tested well below what you would guess.

For B31.1, B31.3 and B31.9 the hydro minimum is 1.5 × design pressure — but B31.3 raises it for lines designed hot, no component may be taken past its own rating, and the plumbing codes work off working pressure instead. So 1.5 × is a sanity check on the number you are handed, not a replacement for it. If there is no written test pressure, there is no test yet.

Code	Hydro test	Hold
ASME B31.3 process	1.5 × design, raised for hot lines	10 min, then inspect every joint
ASME B31.1 power	1.5 × design at every point	10 min, then may drop to design to inspect
ASME B31.9 building services	1.5 × design	10 min
IPC / UPC water supply	Water at not less than working pressure	15 min minimum (IPC 312.5, UPC 609.4)
IPC / UPC drainage and vent	10 ft head of water, or 5 psi air (not on plastic, see 23.11)	15 min

Code minimums (B31.3 345.4, B31.1 137.4, B31.9 937, IPC 312, UPC 609/712). Editions and local amendments change these — the test package governs.

A relief valve left out is how a test kills somebody next month

Every gauge, relief valve, rupture disc and control valve that came out for the test has to go back in, and the system is not a system again until it has. A line put into service with its relief gagged or missing has no protection at all and nothing about it looks wrong.

That is why the list matters. Written down on the way out, checked off on the way back in, by two people.

Trapped air is what makes a hydro dangerous

An air pocket in a "hydrostatic" test is a pneumatic test in that section, and it will let go with all the energy of one. Vent it properly, every time.

Where the gauge sits matters

Water adds 0.433 psi per foot of height. A gauge at the bottom of a 100 ft riser reads about 43 psi more than one at the top. Know where the test pressure is supposed to be read, and don't take the low point past what it is rated for. Worked example in 16.12.

Weight check before you fill

400 ft of 6" holds 600 gallons — 5,000 lb. An empty 8" line is 29 lb/ft and 50 lb/ft full. If the supports aren't all in and tight, the line finds out for you.

Sources: ASME B31.1, B31.3 and B31.9 (hydrostatic tests); IPC and UPC (plumbing tests). Your test package governs.

The reason pneumatic tests are treated differently: compressed air stores energy the whole length of the line, and a failure releases all of it at once. A hydro that fails weeps. A pneumatic test that fails throws pipe — same pressure, entirely different consequence. If there is any way to test with water, test with water. If there is not, the procedure and the barricade are not paperwork: keep everyone out, step the pressure up and hold, and never start one without written permission and the engineer's procedure in your hand.

Water versus air at the same pressure

Step through it

Simplified drawing of how it works, not any one brand; the numbers are examples.

Treat this as the dangerous operation it is

Compressed gas stores enormous energy. A pipe that fails under air doesn't weep — it comes apart and throws pieces. Pneumatic testing is done only when hydro genuinely isn't possible, under a written procedure, with the area cleared.

ASME B31.3 pneumatic
Test pressure	1.1 × design; no more than the lesser of 1.33 × design or 90% of yield stress
First stop	Half the test pressure or 25 psi, whichever is less — preliminary check
Then	Up in steps, holding at each, to test pressure
Leak check	Drop back to design pressure before anybody walks it
Relief on the rig	Set no higher than test pressure + the lesser of 50 psi or 10%

B31.3 345.5. B31.1 is 1.2–1.5 × design (137.5). The procedure governs.

Barricade the area and keep everybody out of line with joints, caps and blinds. The exclusion distance comes from the stored energy in the line (ASME PCC-2 Part 5, Article 501, has the method) and it is written in the procedure — it is often much further than people expect.
Never stand in front of a blind or a cap under pressure, and never approach to "just check something" while it's up.
Bring it up in small steps with a hold at each, inspecting from a distance.
Soap-test joints at the preliminary step and after the pressure has come back down to design — never at full test pressure.
Never on PVC or any plastic. It shatters.
Relief device on the test rig, sized and set, so the system can't be over-pressured.

The usual sequence

A lot of jobs run a low-pressure pneumatic leak test first — B31.3 caps it at 25 psi — to find the obvious misses cheaply, then a full hydro for the record. That's a good order — it saves draining and re-filling.

Sources: ASME B31.3 and B31.1 (pneumatic tests). Your test package governs.

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Stored energy

A line is hot, pressurized or full until you personally proved it isn't. Lock it, tag it, try it, bleed it. Never take another man's word for a valve position.

Never stand under a load. Not for a second. Tag line, not hands.
Never put your hand where you wouldn't put your face.
Hot work — permit, fire watch, blanket, extinguisher, and know where the sparks land two floors down. Full page at 12.4.
Grinders — wheel rated at or above the tool's RPM, guard on, face shield over safety glasses, let it stop before you set it down.
Falls kill more construction workers than anything else, every year, and pipe work is elevated work. Tie off at six feet and up, check the harness before you put it on, and never be unhooked in the air. The whole thing — the numbers, the clearance math, what counts as an anchor and what does not — is 12.2. Ladders and lifts are 12.3.
Confined space (1926 Subpart AA) — permit, gas test, attendant. Every time. And a rescue plan before anybody goes in, because you do not enter to pull somebody out. Most people who die in a confined space are the second person down.
Clamp the pipe, don't hold it, and support the drop so it can't bind and kick.
Silica and fumes. Cutting cast iron, grinding, welding galvanized — respirator and ventilation, not a bandana. Stainless is its own hazard: grinding and welding it puts off hexavalent chromium, which has its own OSHA standard and its own exposure limit. Local exhaust, not an open door.
Housekeeping is safety. Most injuries on a pipe job are trips, falls and rolling pipe.

Argon and nitrogen will put you down with no warning

A purge gas is not poisonous — it just has no oxygen in it, and that is enough. Argon is heavier than air and pools in pipe, in pits, in trenches and in any low spot. You do not smell it, you do not cough, and you do not get a warning: you get one breath and your legs go.

Never put your head into a purged vessel or a large bore line. Vent the purge to atmosphere, not into the space you are standing in. If a purged volume is big enough to get into, it is a confined space and it gets a permit, a gas test and an attendant like any other.

And the same rule as above applies — do not go in after somebody who went down. That is how one body becomes two.

Old insulation — stop and ask

Pipefitters are the trade asbestos was written about. It is in pipe insulation, in block and wrap, in old gaskets, in packing and in fireproofing, and every one of those is something you are asked to cut into on a renovation.

If the building is old enough that you are wondering, stop. Do not cut it, scrape it, saw it or sweep it. Nothing about it looks dangerous, and there is no exposure you will feel. It is the owner's job to survey it and a licensed abatement contractor's job to remove it.

Galvanized

Welding, burning or grinding galvanized pipe puts off zinc oxide fume — metal fume fever, and worse with enough exposure. Grind the coating back well past the weld zone, ventilate it, and wear the right respirator.

Zeroed and taggedA lock and tag on an isolation valve with the energy actually bled off and the gauge reading zero in the same frame. A hot work permit and a fire watch with an extinguisher in reach. PHOTO

Sources: OSHA 29 CFR 1926 and 1910; your site’s safety program governs.

Falls kill more construction workers than anything else, every single year, and pipe work is elevated work — racks, steel, lifts, open floors. This is the page where being roughly right is not good enough, because the equipment only works if the math underneath it works.

When it is required

Where you are	Starts at
Construction	6 ft
Scaffolds	10 ft
Steel erection	15 ft
Plant maintenance (general industry)	4 ft
Over equipment	Any height
Any open hole	Cover it, any depth

A hole gets a cover or a guardrail whatever its depth (1926.501(b)(4)); the 6 ft trigger for tying off is the same over a hole as anywhere else on the job. Construction is OSHA 1926 Subpart M. Scaffolds are Subpart L. Steel erection is Subpart R, where the trigger for connectors is 30 ft or two storeys, whichever is less. Maintenance in a running plant is the general industry standard, 1910 — but new construction or alteration inside a plant is still 1926, and still 6 ft. Your site's program can be — and often is — stricter than any of these. It never gets looser. When two rules disagree, the tighter one governs.

The three parts, and all three have to be good

Anchor: What you are tied to. 5,000 lb per person attached, or engineered to a safety factor of at least two under a qualified person.
Body wear: A full-body harness. Body belts have been illegal for fall arrest since 1 January 1998 — a belt stops the fall by folding you in half.
Connector: The lanyard or retractable between the two, with locking snaphooks on both ends.

The numbers, and why they are what they are

A 6 ft shock-absorbing lanyard needs 18-1/2 feet below the anchor before it has finished stopping you. With the anchor at D-ring height, about 5 ft above the deck, that is roughly 13-1/2 feet of clear space under your boots. Less than that and the lanyard works exactly as designed and you still hit the floor — which is what a retractable is for.

Limit	Figure	Cite
Anchor, per person	5,000 lb	(d)(15)
Force on you	1,800 lb	(d)(16)(ii)
Free fall, max	6 ft	(d)(16)(iii)
Deceleration, max	3.5 ft	(d)(16)(iv)
Guardrail height	42" ±3"	(b)(1)
Guardrail force	200 lb	(b)(3)
Rescue after a fall	Prompt	(d)(20)

All of them from 29 CFR 1926.502. Body belts have not been acceptable for fall arrest since 1 January 1998, and only locking snaphooks since the same date.

Worked — how much air do you need? Six foot shock-absorbing lanyard, anchored level with your D-ring:
Free fall, the lanyard paying out = 6.0 ft
+ deceleration, the pack tearing open = 3.5 ft
+ you, D-ring to boots (about 5 ft) plus a foot of harness stretch = 6.0 ft
+ safety margin = 3.0 ft
6.0 + 3.5 + 6.0 + 3.0 = 18.5 ft, measured down from the anchor.
Your D-ring rides about 5 ft above the deck, so that is 18.5 − 5 = 13.5 ft of clear space under your boots.
Working twelve feet up off a slab, that lanyard cannot stop you before the floor does. It is the wrong equipment, not a reason to shrug — a retractable catches you in the first foot or two, and that is exactly what it is for.

Tied off at your feet is not tied off

A 6 ft lanyard clipped to something level with your boots lets you fall the 6 ft of lanyard plus the 5 or 6 ft from your feet up to your D-ring before it starts doing anything. That is eleven or twelve feet of free fall against a legal limit of six — and the shock that comes with it is past what the harness is built to put into you.

Anchor overhead wherever you possibly can. If the only anchor is at foot level, you need a retractable rated for foot-level or leading-edge use — not a lanyard, and not a longer lanyard.

A pipe is not an anchor

Five thousand pounds. Not a sprinkler line, not conduit, not a duct hanger, not unistrut, not a hanger rod, not the handrail, not a ladder, and not the pipe you are installing. Everything on that list has been used, and some of them have failed with somebody on the end.

If you cannot point at what carries 5,000 lb, stop and ask. The engineered anchor is somebody's job to provide, and it is a fair thing to ask for.

Wearing it, and checking it

Check it before you put it on, every shift. Run the webbing through your hands in an inverted V — cuts, frays, burns, chemical damage, pulled or missing stitching.
Hardware — D-rings and buckles for cracks, distortion, sharp edges and corrosion. Snaphooks must latch and lock on their own.
The energy absorber pack. If the impact indicator has deployed, or the stitching has started to pull, it has already arrested a fall. It is done.
Dorsal D-ring between the shoulder blades, straps snug, leg straps tight enough that you can get a flat hand under and no more, chest strap at mid-chest. A loose harness is what turns a stopped fall into a broken back.
Anything that has taken a fall comes out of service permanently — harness, lanyard, retractable and the anchor connector. It gets cut up, not put back in the gang box.
No knots, no wrapping the lanyard round a beam and hooking back to itself unless it is a tie-back lanyard rated for it, no hook-to-hook, and no hooking two lanyards together to get more reach.

100 percent tie-off means 100 percent

The moment you are most likely to fall is the moment you are moving. A twin-leg (Y) lanyard lets you hook the second leg on before the first comes off, so you are never in the air unattached. Free-climbing between two anchors with the lanyard over your shoulder is the single most common way a properly-equipped hand falls.

Being caught is not being saved — there has to be a rescue plan

A man hanging in a harness is in trouble on a clock. Once he is suspended and not moving, blood pools in his legs and stops coming back up; it can turn serious in minutes, and it can happen to somebody who is conscious, talking and apparently fine. OSHA requires prompt rescue for exactly this reason, and prompt does not mean waiting for the fire department.

So before anybody goes up: who is getting him down, with what, and how long will it take? If the honest answer is a phone call, you do not have a plan. Relief straps let a suspended man stand in his own harness and buy time — they cost almost nothing and they belong on the harness before they are needed.

And if you are the one hanging: keep your legs moving, push against anything you can reach, get your knees up. Do not go still.

Ladders, lifts and the holes you leave behind are 12.3.

A harness inspection, step by stepHands running the webbing in an inverted V, a cut strap, a pulled stitch, a deployed impact indicator, and a distorted D-ring. Close and in focus — this is the set people will actually use. PHOTO

Fitted right and fitted wrongSame man, two frames: dorsal D-ring centred between the shoulder blades with straps snug, then the same harness slack with the D-ring down by his belt. PHOTO

Anchors, good and badAn engineered beam anchor and a properly wrapped sling, next to what people actually tie to — a sprinkler line, conduit, a hanger rod, a handrail. PHOTO

Sources: OSHA 29 CFR 1926 Subpart M (1926.501 and 1926.502).

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Fourteen calculators and your cut list. The Calc tab opens the first one in this grid. Tap any other to open it, and tap All calculators to come back here. Every one shows the math underneath, so you can check it by hand or learn it as you go.

Pick a calculator

Offset calculator

Measure three things between the two pipes: the rise (how much higher or lower B is), the run (how far along the line B is) and the roll (how far over to one side). From those it works out the angle the fittings have to be, the travel and the cut — and which stock fittings would fit instead. Pick the size and it fills the take-outs for whatever angle comes out. Already picked your fittings and just need to know how much run they take? Change What do you have.

What do you have

Rise

Difference in elevation, centreline to centreline

Roll

Over to one side, centreline to centreline. 0 if it only rises

Measured from — can't get to the centre of a pipe? Tape to its top, bottom or side and pick it here

Rise, on pipe A

Rise, on pipe B

Run

Along the line, measured the way you pick below

The run is measured

Fitting angle

Take-outs — filled from the size for any angle

Material

Pipe size

Elbows

Take-out A

Take-out B

Root gap each joint

0 if your shop pulls the joints closed

Which way it runs — turns the drawing, the math stays the same

Side A comes in from

Side B ends up

and the roll takes it

True offset

—

Travel C to C

—

Run / advance

—

Cut this pipe

—

Cut list

Every piece you add from the cut length and offset calculators lands here with a piece mark, so a spool goes to the saw as one list. It stays on this phone until you clear it.

Job

Nothing on the list yet. Work a cut and tap Add to cut list.

Notes for this job

Photos for this job kept on this phone

Take a photo Pick photos

Fab layout

The advanced fab math in one place: cut an elbow to any angle, mitered turns, saddles and laterals, Ys, orange peels, dummy legs, flange bolt holes, pipe bends and parallel lines. Pick what you are making, fill in the boxes, and it gives you the marks, the stations and a picture of the cut, with a 3D view of the piece cut, fitted and welded that you can turn.

What are you laying out?

Lines in the bank

Spacing, centre to centre (in)

line to line, square to the run

Size

Make

Petals

What is in your hand

The shoe: The curved casting the conduit wraps around. Its radius is fixed, and that radius is where take-up, gain and shrink all come from.
Degree marks: Cast into the shoe or the frame. Usually 10, 22½, 30, 45 and 60, plus the 90.
The hook: Catches the conduit and gives you something to stand on. Your foot goes here, not on the handle.
The handle: Leverage only. You steer with it; the foot does the work.

The three reference marks

Mark	Put your line on it for
Arrow	Stub-ups, and both bends of a simple offset — flip the conduit 180° between them. The workhorse.
Star	Back-to-back bends — the second 90 of a U.
Rim notch / teardrop	The centre of the bend. The 45 in a three-point saddle.

Read the bender in your hand

Manufacturers do not all mark the same way, and take-up is stamped on most benders for a reason. Bend one piece of scrap and measure it before you cut a bundle to a number you got out of a book — this one included.

Which conduit

EMT: Thin wall. Set-screw or compression fittings, no threads. What a hand bender is made for.
IMC: Heavier wall, threadable. Bends harder and holds its shape better.
Rigid (RMC): Heaviest, threaded. Beyond small sizes this is a hydraulic bender's job, not a hand bender's.

Keep it flat and keep it square

Bend on the floor, not on a bench or across a hole. Steady foot pressure all the way through the bend, and keep the conduit flat — almost every dogleg starts with the bender rocking or the conduit lifting halfway through.

Sources: The bender maker’s instructions (marks vary by brand).

The bend eats length. Take-up is how much, and subtracting it is the whole trick to a 90 that lands where you said it would.

MARK = DESIRED STUB HEIGHT − TAKE-UP

Conduit	Typical take-up
1/2" EMT	5"
3/4" EMT	6"
1" EMT	8"
1-1/4" EMT	11"

Typical for common hand benders. Yours may differ — it is usually stamped on the shoe. Verify with one test bend.

Worked — a 10" stub in 1/2" EMT 10 − 5 = 5"
Measure 5" back from the end, mark it, put the mark on the arrow, bend to 90°.

Where the mark actually goes

Step through it

Sources: The bender maker’s instructions; the math is worked out for this book.

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Everything in this section is the same one trick. A pipe is a flat sheet rolled up. Unroll it in your head, draw the cut on the flat, roll it back, and burn what you drew.

A cut that is a straight line on the pipe becomes a curve once the skin is unrolled. That is the whole reason you cannot wrap a square line round a pipe and call it a miter.

The four steps — every layout in this section

Wrap. A strip of paper, roofing felt or a proper wrap-around, long enough to go round the pipe with an overlap. Line the two edges up with each other, not with the pipe — that's what makes the mark square.
Divide. Step the circumference into 16 equal parts. Those are your stations. Number them.
Ordinates. At each station, measure one distance from a common square base line. That distance is the ordinate. Where the numbers come from is what the rest of this section is about.
Connect and cut. Join the marks with a smooth curve — a piece of banding or a scrap of 1/8" rod bent to follow makes a better fair curve than a free hand. Burn on the waste side and grind to the line — torch technique and the kerf allowance are in 1.5c.

Why 16

Sixteen stations is fine enough that the curve between marks is almost straight, and it's easy to get: fold the wrap in half, in half, in half, in half. On anything under 3" use 8 and save the time. On 18" and up, use 24 or 32 — a 24" pipe has 4-11/16" between 16 stations and you'll cut flats into the curve.

Two rules that save every layout

Base line

Every ordinate on one piece gets measured from the same square line. Not from the pipe end — the pipe end is never square until you make it square. Square a line all the way round first, and measure everything from that.

Station one

Mark station 1 with a punch or a deep soapstone cross and carry that mark onto both pieces before you cut anything. Every one of these layouts is symmetrical, which means the pattern will fit four different ways and only one of them is right. When you lose station 1 you lose the job.

What goes where

15.4–15.5	Cutting a pipe off at an angle, and turning a corner with mitered pieces.
15.6–15.10	Two pipes running into each other — tees, saddles, off-centre and 45° branches.
15.11–15.14	Cones and heads. Reducers, transitions, dished heads.
15.15–15.20	Coils, steel, supports on elbows, bolt holes, and pipe bends.

Stations and circumference numbers: 15.2 and 15.3. Start there if you have never wrapped a pipe.

Sources: Geometry and ordinates worked out for this book; check any of them with the formulas shown.

The spacing between equal marks round a pipe, measured along its surface. Circumference is OD × 3.1416 — everything else on this page is that number divided up.

Sixteen stations, got by folding rather than measuring — no tape and no math, and any error in your circumference cancels itself out. The quarter marks are the ones you punch.

CIRCUMFERENCE = OD × 3.1416 · SPACING = CIRC ÷ PARTS

Size	OD	Circ	÷3	÷4	÷6	÷8	÷12	÷16	÷24
1/2"	0.840	2.64	0.880	0.660	0.440	0.330	0.220	0.165	0.110
3/4"	1.050	3.30	1.100	0.825	0.550	0.412	0.275	0.206	0.137
1"	1.315	4.13	1.377	1.033	0.689	0.516	0.344	0.258	0.172
1-1/4"	1.660	5.22	1.738	1.304	0.869	0.652	0.435	0.326	0.217
1-1/2"	1.900	5.97	1.990	1.492	0.995	0.746	0.497	0.373	0.249
2"	2.375	7.46	2.487	1.865	1.244	0.933	0.622	0.466	0.311
2-1/2"	2.875	9.03	3.011	2.258	1.505	1.129	0.753	0.565	0.376
3"	3.500	11.00	3.665	2.749	1.833	1.374	0.916	0.687	0.458
4"	4.500	14.14	4.712	3.534	2.356	1.767	1.178	0.884	0.589
5"	5.563	17.48	5.826	4.369	2.913	2.185	1.456	1.092	0.728
6"	6.625	20.81	6.938	5.203	3.469	2.602	1.734	1.301	0.867
8"	8.625	27.10	9.032	6.774	4.516	3.387	2.258	1.694	1.129
10"	10.750	33.77	11.257	8.443	5.629	4.222	2.814	2.111	1.407
12"	12.750	40.06	13.352	10.014	6.676	5.007	3.338	2.503	1.669
14"	14.000	43.98	14.661	10.996	7.330	5.498	3.665	2.749	1.833
16"	16.000	50.27	16.755	12.566	8.378	6.283	4.189	3.142	2.094
18"	18.000	56.55	18.850	14.137	9.425	7.069	4.712	3.534	2.356
20"	20.000	62.83	20.944	15.708	10.472	7.854	5.236	3.927	2.618
24"	24.000	75.40	25.133	18.850	12.566	9.425	6.283	4.712	3.142

What each column is for

÷3	Trisecting — a true Y, a three-leg support, 120° work.
÷4	Quarter marks. Clocking a flange, four tacks, top-dead-centre.
÷8	Small bore layout. Bolt holes go on the bolt circle, not the pipe: 15.19.
÷12	Cone and reducer triangulation, orange peel gores.
÷16	The standard for miters, saddles and laterals. Most of this section.
÷24	Big bore — 18" and up, where 16 stations leaves flats in the curve.

Do it by folding, not by measuring

Wrap the paper, mark the overlap, take it off, and fold it in half four times. Sixteen equal parts, dead accurate, no math, and any error in your circumference measurement cancels itself out. The table is the distance along the surface, for a wrap or a flexible rule. Dividers span the straight line between two marks, which is shorter: on 16 or 24 parts the table is close enough to start from, but on 3 to 12 parts set them to the chord instead, OD × sin(180° ÷ parts), as 15.19 does for bolt holes.

Close the circle

Step it round with dividers and the last space is never the same as the first. Split the difference and step it again. Two or three passes and it closes. Never just crowd the error into the last space — it lands on station 16, which is where your seam goes.

Sources: Geometry and ordinates worked out for this book; check any of them with the formulas shown.

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American pipe thread is tapered — 3/4" of taper per foot of length, on the diameter. That taper is what seals it, and it is why a threaded joint gets tighter the further you drive it.

A pipe thread is a wedge. It tapers 3/4" in a foot, so the further the fitting goes on the tighter it gets — until it splits the fitting. Hand tight gets you engaged, the wrench gets you sealed, and the last few threads are there so you have somewhere to go. NPT threads seal on the flanks as the taper wedges, not on the crests — which is why dope or tape is a lubricant and a filler, not the seal itself. Two or three threads showing past the fitting is right. None showing means you went too far.

TAPER = 3/4" PER FOOT · 1° 47' PER SIDE

Thread data nominal per ASME B1.20.1. Machine screw tap drills (16.2) follow ASME B1.1.

NPT thread data

HAND TIGHT	How far it screws in by hand, per B1.20.1. It is not the number you subtract for a cut length — wrenching it home buries the pipe deeper than this. Use the fuller, wrench-tight engagement in 2.2 for that.
EFFECTIVE	Length of full-form thread the die cuts. Set by formula — roughly hand tight plus wrench makeup on the small sizes, more than that on the big ones.
OVERALL	Total thread including the imperfect run-out at the end. What you see on the pipe.
TURNS	Roughly how many turns of thread are engaged hand tight.

Size	TPI	Hand tight	Effective	Overall	Turns
1/8"	27	0.162	0.2639	0.3924	4.4
1/4"	18	0.228	0.4018	0.5946	4.1
3/8"	18	0.240	0.4078	0.6006	4.3
1/2"	14	0.320	0.5337	0.7815	4.5
3/4"	14	0.339	0.5457	0.7935	4.7
1"	11.5	0.400	0.6828	0.9845	4.6
1-1/4"	11.5	0.420	0.7068	1.0085	4.8
1-1/2"	11.5	0.420	0.7235	1.0252	4.8
2"	11.5	0.436	0.7565	1.0582	5.0
2-1/2"	8	0.682	1.1375	1.5712	5.5
3"	8	0.766	1.2000	1.6337	6.1
4"	8	0.844	1.3000	1.7337	6.8
6"	8	0.958	1.5125	1.9462	7.7
8"	8	1.063	1.7125	2.1462	8.5

Wrench makeup — how far past hand tight

2 TO 3 TURNS PAST HAND TIGHT

2 to 3 turns on 1/2" through 1"; 1-1/2 to 2 on the bigger sizes (2.4). Not "until it stops" — a tapered thread never stops, it just splits the fitting. Count turns.

Thread types you'll meet

NPT	Tapered, seals on the thread flanks. Needs dope or tape. The default on everything in this book.
NPS	Straight. Does not seal on the thread — needs a gasket or an O-ring. Common on lock nuts and some unions.
NPTF	Dryseal. Crests and roots interfere so it seals without dope. Hydraulics and fuel.
BSPT / BSPP	British, 55° thread form. Looks close, will not mate. Imported equipment.

NPT into NPS

A tapered male into a straight female will start, go two turns, and feel tight. It is not sealed — it's wedged. Check the port before you make up anything on imported equipment, and check it again if the thread feels wrong.

Reading a thread on the pipe

Lay a rule on it and count crests in an inch — that's your TPI, and TPI plus the diameter tells you the size. 11-1/2 crests in an inch on something around 2-3/8" OD is a 2" pipe thread, whatever the tag says.

Sources: ASME B1.20.1 (NPT); ASME B1.1 (unified threads).

What size socket, what size drill. The two lookups you need at the bench and never have on you.

Wrench across flats

Heavy hex is what's on flange bolting. Standard hex is everything else — brackets, clamps, machine bolts.

Bolt	Heavy hex	Bolt	Std hex
1/2	7/8	1/4	7/16
5/8	1-1/16	5/16	1/2
3/4	1-1/4	3/8	9/16
7/8	1-7/16	7/16	11/16
1	1-5/8	1/2	3/4
1-1/8	1-13/16	9/16	7/8
1-1/4	2	5/8	15/16
1-3/8	2-3/16	3/4	1-1/8
1-1/2	2-3/8	7/8	1-5/16
1-5/8	2-9/16	1	1-1/2
1-3/4	2-3/4
2	3-1/8

HEAVY HEX = (BOLT × 1.5) + 1/8"

The 1.5 rule works on heavy hex, not on standard hex

Heavy hex really is bolt × 1.5 plus an eighth, all the way up. Standard hex is not bolt × 1.5 — it holds at 3/8, 1/2, 5/8, 3/4, 7/8 and 1", and it is wrong at 1/4, 5/16, 7/16 and 9/16 — the real sizes are 7/16, 1/2, 11/16 and 7/8 (B18.2.2 — the 5/8 and 13/16 you may have seen are bolt heads, not nuts). Read the table for those four.

Pipe wrench to pipe size

10"	up to 1-1/2"
14"	up to 2"
18"	up to 2-1/2"
24"	up to 3"
36"	up to 5"
48"	up to 6"

Two wrenches, not one wrench and a cheater. A cheater on a 24" is how you snap a jaw and take a knuckle with it.

Drill sizes for pipe taps

NPT taper taps. Pipe-tap drill sizes vary a bit by tap maker and target thread depth — treat this as a starting point and check it against the tap you're running. Drill straight, tap slow, back it off every half turn and keep oil on it.

Pipe tap	Drill	Decimal
1/8-27	R	.3390
1/4-18	7/16	.4375
3/8-18	37/64	.5781
1/2-14	23/32	.7188
3/4-14	59/64	.9219
1-11.5	1-5/32	1.1563
1-1/4-11.5	1-1/2	1.5000
1-1/2-11.5	1-47/64	1.7344
2-11.5	2-7/32	2.2188
2-1/2-8	2-5/8	2.6250
3-8	3-1/4	3.2500
4-8	4-1/4	4.2500

Tap drill sizes — machine threads

75% thread engagement, which is what you want for steel.

Thread	Drill	Decimal
#6-32	36	.1065
#8-32	29	.1360
#10-24	25	.1495
#10-32	21	.1590
1/4-20	7	.2010
1/4-28	3	.2130
5/16-18	F	.2570
5/16-24	I	.2720
3/8-16	5/16	.3125
3/8-24	Q	.3320
7/16-14	U	.3680
7/16-20	25/64	.3906
1/2-13	27/64	.4219
1/2-20	29/64	.4531
9/16-12	31/64	.4844
5/8-11	17/32	.5312
3/4-10	21/32	.6562
7/8-9	49/64	.7656
1-8	7/8	.8750

TAP DRILL ≈ MAJOR DIA − (1 ÷ TPI)

Close enough for any thread not in the table. 1/2-13: .500 − .077 = .423, and the chart says .4219.

Clearance holes

Not the same as a tap drill. Clearance is the next drill up from the bolt: 1/2" bolt → 9/16" hole. Flange bolt holes are 1/8" over the stud — a 3/4" stud goes in a 7/8" hole.

Tapping into a pressure boundary

Drilling and tapping a fitting, a valve body or a header for a gauge or a drain is a pressure-boundary modification. It needs the spec, the engineer, and a wall thickness that can carry the thread. Don't take a drill to a line because someone needs a gauge port.

The drill and the tap it goes withA tap drill sat next to its tap with the chart in frame, and a hole tapped correctly beside one drilled to the tap size that stripped. PHOTO

Sources: ASME B1.20.1 (NPT); tap drill sizes from common published charts. Tap makers vary.

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Every number on a tape is a fraction. Every number out of a calculator is a decimal. This is how you get between them without thinking about it.

Decimal → fraction

× 16 = SIXTEENTHS × 32 = THIRTY-SECONDS × 64 = SIXTY-FOURTHS

Multiply, round to the nearest whole number, put it over what you multiplied by, reduce.

Worked 0.6875 × 16 = 11.0 → 11/16 → 11/16"
0.42 × 16 = 6.72 → round 7 → 7/16"
0.42 × 64 = 26.9 → round 27 → 27/64" (same number, finer tape)
3.8125 → whole 3, then .8125 × 16 = 13 → 3-13/16"

Fraction → decimal

TOP ÷ BOTTOM

Worked 5/8 → 5 ÷ 8 = 0.625
7-3/16 → 3 ÷ 16 = .1875 → 7.1875

The whole tape, to 64ths

Copper-coloured decimals are the ones that land on a 16th — the marks actually on most tapes.

Frac	Dec	Frac	Dec	Frac	Dec	Frac	Dec
1/64	0.0156	17/64	0.2656	33/64	0.5156	49/64	0.7656
1/32	0.0312	9/32	0.2812	17/32	0.5312	25/32	0.7812
3/64	0.0469	19/64	0.2969	35/64	0.5469	51/64	0.7969
1/16	0.0625	5/16	0.3125	9/16	0.5625	13/16	0.8125
5/64	0.0781	21/64	0.3281	37/64	0.5781	53/64	0.8281
3/32	0.0938	11/32	0.3438	19/32	0.5938	27/32	0.8438
7/64	0.1094	23/64	0.3594	39/64	0.6094	55/64	0.8594
1/8	0.1250	3/8	0.3750	5/8	0.6250	7/8	0.8750
9/64	0.1406	25/64	0.3906	41/64	0.6406	57/64	0.8906
5/32	0.1562	13/32	0.4062	21/32	0.6562	29/32	0.9062
11/64	0.1719	27/64	0.4219	43/64	0.6719	59/64	0.9219
3/16	0.1875	7/16	0.4375	11/16	0.6875	15/16	0.9375
13/64	0.2031	29/64	0.4531	45/64	0.7031	61/64	0.9531
7/32	0.2188	15/32	0.4688	23/32	0.7188	31/32	0.9688
15/64	0.2344	31/64	0.4844	47/64	0.7344	63/64	0.9844
1/4	0.2500	1/2	0.5000	3/4	0.7500	1	1.0000

Rounding on the job

Round to the nearest 16th for anything you are cutting with a saw or a torch. Round to 32nds for machine work and gasket stuff. Never round in the middle of a calculation — carry the decimals all the way to the end, then round once. Round three times in one offset and you'll be 1/8" out and not know where it went.

The trap

0.5 is not 5/8, and 0.75 is not 7/8. A decimal point is not a fraction bar. If you catch yourself reading 4.3 as 4-3/8, stop and multiply: .3 × 16 = 4.8, so it's 4-5/16. Miss that and you are 1/16" heavy every cut.

Sources: Computed for this book.

Survey instruments, grade sheets, pump curves and most engineering dimensions are in decimal feet. Your tape is not. This is the bridge.

INCHES ÷ 12 = DECIMAL OF A FOOT

Worked 7-1/2" → 7.5 ÷ 12 = 0.625'
4'-3 1/4" → 3.25 ÷ 12 = .271 → 4.271'

Inches and eighths → decimal of a foot

Read down the inch column, across to the fraction.

In	0	1/8	1/4	3/8	1/2	5/8	3/4	7/8
0"	0.0000	0.0104	0.0208	0.0312	0.0417	0.0521	0.0625	0.0729
1"	0.0833	0.0938	0.1042	0.1146	0.1250	0.1354	0.1458	0.1562
2"	0.1667	0.1771	0.1875	0.1979	0.2083	0.2188	0.2292	0.2396
3"	0.2500	0.2604	0.2708	0.2812	0.2917	0.3021	0.3125	0.3229
4"	0.3333	0.3438	0.3542	0.3646	0.3750	0.3854	0.3958	0.4062
5"	0.4167	0.4271	0.4375	0.4479	0.4583	0.4688	0.4792	0.4896
6"	0.5000	0.5104	0.5208	0.5312	0.5417	0.5521	0.5625	0.5729
7"	0.5833	0.5938	0.6042	0.6146	0.6250	0.6354	0.6458	0.6562
8"	0.6667	0.6771	0.6875	0.6979	0.7083	0.7188	0.7292	0.7396
9"	0.7500	0.7604	0.7708	0.7812	0.7917	0.8021	0.8125	0.8229
10"	0.8333	0.8438	0.8542	0.8646	0.8750	0.8854	0.8958	0.9062
11"	0.9167	0.9271	0.9375	0.9479	0.9583	0.9688	0.9792	0.9896

Between the columns

A 16th is .0052'. A 32nd is .0026'. Need 5-7/16"? Take 5-3/8 (.4479) and add .0052 → .4531'.

The ones worth knowing cold

1": .0833'
1/8": .0104'
1/4": .0208'
1/2": .0417'
3": .250'
6": .500'
9": .750'

Grade sheets

A drawing that says INV 98.75 means ninety-eight and three-quarters of a foot — 98'-9", not 98'-7 1/2". Mixing the two on a sanitary line is how a run ends up flat.

Sources: Computed for this book.

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This section teaches the math. The rest of the book gives you the answer; this one shows you where the answer came from, one step at a time, with a worked example on every page.

Five tracks, in this order

The calculator comes first on purpose. It is the tool you use on every page after it, and most of us were handed one and never actually shown what the second function key does.

18.2	The tool. Your calculator — the function keys, the inverse key, and the one setting that quietly makes every trig answer wrong if it is set the other way.
18.3–18.7	Numbers. Fractions to decimals and back, doubling and halving on the pipe without a calculator, angles and degrees, squares and square roots.
18.8–18.13	The triangle. Naming the sides, finding a missing one, sine cosine and tangent, finding an angle, solving the whole thing off one side and one angle, and the 45 on its own page.
18.14–18.23	The payoff. Elbows, where take-out actually comes from, then every offset there is — simple, shortest, combination, rolling and combination rolling, each one built out of the one before it.
18.24–18.27	Circles. Its own track, take it whenever you like — pi, circumference, radians, chords, laying out a flange with dividers, area and volume.
18.28–18.29	Practice, and the answers. Fourteen problems. Work them on paper before you look.

Three habits that make the math easy

Work in decimals, convert once at the end. Turn every fraction into a decimal before you start, do the whole problem, and only turn the final answer back into a fraction. Convert in the middle and the rounding errors stack up.
Write it down. Every step, on the back of the print or in a notebook. A number you did in your head is a number nobody can check — including you, ten minutes later.
Sanity-check the answer. Is the travel longer than the offset? It has to be. Is the cut shorter than the center-to-center? It has to be. Catching a wrong answer costs a second; cutting one costs a joint.

You do not have to memorise any of this

The constants in 12.10, the tables in 17, and the calculators in 13 will get you through any day on the job. This section is for the days the table does not have your number in it — an odd angle, an odd fitting, a spot nobody drew. That is when knowing where the numbers come from is worth something.

How to work a problem out of this section 1 Draw it, even badly. Mark what you know.
2 Name the three sides: offset, run, travel.
3 Pick the formula that uses the two you have.
4 Work it in decimal inches all the way through.
5 Take off the take-outs and the gaps, still in decimals.
6 Convert to a fraction once, at the end — then cut.

Sources: Math worked out for this book; check it with the formulas shown.

Any cheap scientific calculator does everything in this book. Here is what the buttons are and the order to press them in.

Do this first, before anything else

Put the calculator in DEGREES. Look for DEG or D in the little display at the top. If it says RAD or GRAD, press the DRG or MODE button until it says DEG. Every answer in this book is wrong if it doesn't.

Test it: type 45, press tan. You should get 1. If you get 1.6198, you are in radians.

The function keys — angle in, ratio out

Key	You type	You get
sin	an angle	opposite ÷ hypotenuse
cos	an angle	adjacent ÷ hypotenuse
tan	an angle	opposite ÷ adjacent

Try these three right now 45 tan → 1
45 sin → 0.7071
22.5 tan → 0.4142 — the stagger number from 8.5, straight out of the machine

Some calculators want the number first, some want the function first. Test on 45 tan. Whichever order gives you 1 is your machine's order — and it will be that order forever.

The inverse key — ratio in, angle out

The same three keys run backwards when you press 2nd (or INV, or SHIFT) first. The little writing above the key — sin⁻¹, cos⁻¹, tan⁻¹ — is what you are reaching for. These are also called the arc functions: arcsin, arccos, arctan. Same thing, older name.

Try it 1 2nd tan⁻¹ → 45
.7071 2nd sin⁻¹ → 45
.4142 2nd tan⁻¹ → 22.5

The plain-English version

Plain key: "I have the angle, give me the number."
2nd + key: "I have the number, give me the angle."
That is the entire difference, and it is the thing most people never get told.

The other keys you will use

x²	Squares whatever is showing. 14 x² → 196.
√	Square root. 277 √ → 16.643.
1/x	Flips a number over. Turns a tangent into a cotangent, or .7071 into 1.414.
π	3.14159… Saves typing it, and saves the rounding.
( )	Brackets. Use them. √( 14 x² + 9 x² ) keeps the machine from rooting only the 9.
M+ / MR	Memory. Park a take-out in there and stop retyping it forty times.

A whole rolling offset, keystroke by keystroke

Rise 14", roll 9", 45° fittings, 2.00" take-outs True offset: 14 x² + 9 x² = 277, √ → 16.643
Travel: ÷ 45 sin → 16.643 ÷ .7071 = 23.537
Cut: − 2 − 2 = 19.537
To a fraction: .537 × 16 = 8.59 → round 9 → 19-9/16"
Roll angle: 9 ÷ 14 = .6429, 2nd tan⁻¹ → 32.7° off top

A phone will do it too

Turn an iPhone sideways in the calculator app and the scientific keys appear. Android calculators have a button or a swipe for the same thing. But a $12 scientific calculator with real buttons works with gloves on, in the cold, with wet hands, and does not ring.

Your calculator, keys namedA plain scientific calculator with the keys you actually use circled: sin, cos, tan, the shift or 2nd key, x², √, and the degree mode indicator on the display. PHOTO

Sources: Math worked out for this book; check it with the formulas shown.

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Before any of the rest of it makes sense, you have to be able to name what you are holding. Half of what sounds like jargon on a pipe job is just precise language for things that would otherwise take a sentence to point at.

A fitting

Every dimension on a fitting is measured to its face, and every dimension on a print is measured to the working point — where the centrelines cross, out in mid-air where there is no metal at all. The distance between those two is the take-out, and subtracting it is the whole job.

Face: The flat end of a fitting, where your pipe stops. Every fitting dimension in this book is measured to a face.
Working point: Where two centrelines cross. It is a point in mid-air with no metal at it, and it is what the print dimensions to.
Take-out: Working point to face. The number you subtract. Also called centre-to-face or centre-to-end.
Throat: The short inside curve of a bend.
Heel: The long outside curve. On a bent pipe this is where the wall thins.
Crotch: The inside corner where a branch meets a run. The hardest spot on any fitting to weld and the first place one cracks.
Bore: The hole through it. Matters because a fitting's bore has to match the pipe's, or you build a hi-lo.

An assembly

A spool is pipe with fittings already on it, made up at the bench and set as one piece. The run is the straight line through it; anything coming off the side is a branch. Prints dimension to the centreline, but hangers, clearances and interferences all get checked at top of pipe and bottom of pipe.

Spool: Pipe with fittings on it, made up at the bench and set as one piece. The unit of work on a fabricated job.
Piece mark: The number written on a spool that matches it to the drawing. Write it the second it is cut.
Run: The straight line through an assembly.
Branch: Anything coming off the side of the run.
Nipple: A short piece of pipe, threaded both ends. A close nipple is all thread with no bare pipe in the middle.
Field weld: A joint deliberately left for the field so the spool can be adjusted. Marked FW on the iso.

Where a dimension is measured to

Mark	Means
CL	Centreline. What prints dimension to, and what all the offset math works in.
TOP	Top of pipe. What you check clearance and headroom against.
BOP	Bottom of pipe. What you set a rack elevation to, because that is what sits on the steel.
TOS	Top of steel. The elevation of the beam or support, not the pipe.
Invert	The inside bottom of a gravity drain. Grade is set to invert, never to the outside.
Crown	Inside top. Used on drainage the same way invert is.

BOP and invert are not the same number

Bottom of pipe is the outside bottom. Invert is the inside bottom. They differ by one wall thickness, which on 12" Sch 40 is .406". Check the wall on whatever you are running.

On a pressure line nobody cares. On a gravity drain it is a flat error at every point — at 1/8" per foot, 3/8" or 1/2" is the whole fall of three or four feet of run. Read which one the print says.

Positions around the pipe

The clock face is how everybody describes a position around a pipe, looking along it in the direction of flow: 12 o'clock is the top, 6 is the bottom, 3 and 9 are the sides. "Seam at 2 o'clock" and "there's a pinhole at 5" are complete instructions.

The spring line is the horizontal centreline — 3 and 9 o'clock — the widest part of the pipe seen from above. It is where a trench bed has to support a pipe and where a clamp gets its grip.

Say it the way the trade says it

None of this is showing off. "Cut the branch back to the crotch" is instant and unmistakable, and "cut that bit where the little pipe joins the big pipe, up in the corner bit" is not. When you can name the parts, you stop describing and start instructing — and people start handing you work.

The full glossary of trade words is 12.9.

The same elbow, labelled with tapeA real LR 90 on a bench with masking tape flags on it: face, throat, heel, bore, and a soapstone dot out in the air where the working point would be. One shot does more than a page of words. PHOTO

A spool with its piece markA finished flanged spool on horses with the piece mark in soapstone, next to the iso it came off, so the two can be read together. PHOTO

Sources: Common trade practice.

Nobody is born knowing this and plenty of hands fake it for years. It takes about ten minutes to learn properly and it is the single most used skill in the trade.

One inch, blown up. You are not reading sixteen identical lines — you are reading a ladder of heights. Find the nearest tall mark you recognise, then count the short ones up from it. Nobody measures by counting all sixteen.

Read the tape: practice

Try it

How the marks work

An inch is divided in half, then each half in half, then again, then again. Four cuts, sixteen pieces. The height of the mark tells you which cut it belongs to — that is the whole system, and it is why you can read a tape at arm's length in bad light.

Mark	Height	How many in an inch
Inch	Tallest, numbered	1
Half	Next tallest	2
Quarter	Shorter	4
Eighth	Shorter again	8
Sixteenth	Shortest	16

Read from the nearest big mark, not from zero

Do not count sixteen little lines. Find the tall mark you can see at a glance — the half, or the quarter — and count the short ones from there. Two short marks past the half is 1/2 + 2/16 = 5/8.

Everybody who reads a tape fast is doing it this way.

Worked — three reads Three short marks past 3" → 3 + 3/16 = 3-3/16"
One short mark past the half, after 7" → 7 + 8/16 + 1/16 = 7-9/16"
One short mark before 5" → 5 − 1/16 = 4-15/16"
That last one is the read people fumble. Counting backward from a number you can see beats counting forward from one you cannot.

Always reduce

Write 3/4, not 12/16. Write 1/2, not 8/16. A cut list in sixteenths is hard to read fast and easy to misread under a hard hat. Divide top and bottom by the same number until it will not go any further. The full conversion tables are 17.1, and if fractions themselves are shaky, 18.3 teaches them from scratch.

You counted	Write
2/16	1/8
4/16	1/4
6/16	3/8
8/16	1/2
10/16	5/8
12/16	3/4
14/16	7/8

Feet and inches

A tape marks every foot, usually boxed or in a different colour. Past that it keeps counting inches, so the 40" mark and the 3'-4" mark are the same place. Prints are in feet and inches; most take-out math is easier in straight inches. Convert once, in writing, and work in one or the other — mixing them mid-calculation is a classic way to lose a foot.

FEET × 12 + INCHES = TOTAL INCHES

Worked 6'-3" → 6 × 12 = 72, + 3 = 75"
Back again: 75 ÷ 12 = 6 remainder 3 → 6'-3"

The other marks on the blade

16" marks: Usually red or boxed. Stud spacing — nothing to do with pipe, but that is what they are.
Black diamonds: Every 19.2", which is five joists per eight feet. Also not yours.
The case length: Printed on the case, normally 3" or so. Butt the case into a corner, read the tape, add it — that is what it is for.

The hook is supposed to be loose

That little bit of slop is not wear. The hook floats by exactly its own thickness, so that hooking over an end and pushing against one both read true. If you squeeze it tight to "fix" it, every inside measurement you take from then on is short by the thickness of the hook.

A hook that is bent, or loose by more than its own thickness, is a different story. That tape is done — and it has been giving you bad numbers for a while.

Burn an inch

On anything long or critical, start at the 1" mark instead of the hook, take your reading, and subtract an inch. Now nothing depends on a bit of stamped metal that has been dropped off a rack fifty times.

Two rules: say it out loud to whoever is on the other end, and both of you burn the same amount. Half the burned-inch mistakes in the trade are one man burning and the other not.

One tape, and do not lend it

Two tapes of different brands can disagree by a sixteenth over ten feet, and both are within their own tolerance. Lay out a whole spool with one tape and check it with another and you will find errors that are not there.

Pick one, mark it, use it for everything on that job.

The ladder of marks, up closeA macro shot of one inch of a real tape so the four heights are unmistakable, then the same inch with 5/8 and 11/16 flagged, because those are the two that get misread. PHOTO

A good hook and a bad oneA hook sliding its proper amount, then one visibly bent, and a shot of a tape started at the 1" mark with the burn called out. PHOTO

Sources: Common trade practice.

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Units

The book is written in feet, inches and sixteenths, because that is what is printed on the drawings and stamped on the fittings on the jobs it is written for. Millimetre equivalents sit in section 17. The calculators work in inches and feet — type 18 1/2, 18-1/2 or 18.5 and they will sort it out — and the Conversions tab in the calculators (13.1) turns fractions, decimals, millimetres and metres into feet and inches and back. The Fraction calc in the same grid adds, subtracts, multiplies and divides them.

A metric edition

Not the same job as a translation. Metric pipe runs to different schedules, different standards and different stock fittings — converting the numbers would give you a book that is right on paper and practically wrong. If it gets built it gets built properly, from metric standards.

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No price rises without at least 30 days notice by email, stating the old price, the new price and the date it starts. A price change never takes effect in a term you already paid for, and the notice tells you exactly how to cancel before it lands.

Failed payments

If a renewal payment fails, you get an email and the card is tried again over the following days. You keep full access while that happens. Update your card under Manage or cancel your plan and everything carries on. If the card still cannot be charged, the plan ends and the paid pages lock. Nothing is deleted, and subscribing again brings it all back.

What happens to your data

Cancelling does not delete anything. Your account and email stay as they are until you ask for them to be deleted (20.1) or until 24 months of inactivity, after which the account is erased and you get an email before that happens. The full detail is in the privacy policy (20.6).

The agreement between you and whoever owns this book. Written to be read, not to be skipped.

The short version

Pay the subscription, use the book on your own devices, do not hand it out or resell it. It is a reference, not an engineering document, and you are responsible for checking anything you cut or build. Cancel whenever you like. If something goes wrong, what you can recover is limited to what you paid. Students aged 13 to 17 use it through a seat from their school, training program or employer.

Effective October 17, 2026 · Version 1.2 · Between you and Pipelogic LLC, an Ohio limited liability company, of 850 Euclid Ave Ste 819 #7312, Cleveland, OH 44114 ("we", "us")

Agreeing to this. Subscribing to or using Field Fitter (the "book") means you accept these terms. If you do not accept them, do not use it.
Who can use it. To buy a subscription or a licence you must be 18 or older and able to enter a contract. If you are using it for an employer, you confirm you can bind that employer, and "you" means both of you. If you are 13 to 17, you may use the book only through a seat on a licence held by your school, training program, union hall or employer (next clause). Nobody under 13 may use it.
Licences for schools, programs and employers. A school, training program, union hall or employer that holds a licence (the "licence holder") accepts these terms for every seat it hands out, and each person on a seat follows them too. A licence holder may give a seat to someone aged 13 to 17 only with any permission its own rules or the law require, including a parent’s or guardian’s where that is needed, and must never give one to anyone under 13. On a school or training licence, the licence holder stays in charge of its students’ records, as 20.6 explains. If a licence holder has a separate agreement with us that both sides signed, such as a purchase order addendum or a student data privacy agreement, that agreement wins wherever it differs from these terms.
Your account. One person, one account. Keep your sign-in to yourself — you are responsible for what happens under it. Tell us at [email protected] if you think somebody else has got into it. Crews and companies: see 20.7 for multi-seat licences, which cost less per hand than sharing a login and do not breach this clause.
Subscription, billing and renewal. The book is sold as a recurring subscription that renews automatically until you cancel. Price, billing period, renewal date, the cancellation method and the refund position are set out in full in 20.4 and form part of this agreement. You can cancel at any time — in your phone’s subscription settings for the App Store or Google Play, or as 20.4 describes for the web; access continues to the end of the period already paid for.
Buying in the app. A subscription bought in the iPhone app is sold through Apple’s App Store, and one bought in the Android app through Google Play. That store takes the payment, and its own terms also apply to the purchase, its renewals and any refund. These terms are between you and Pipelogic LLC only, not Apple or Google. We alone are responsible for the book, for supporting it and for any claim about it, and neither Apple nor Google has to do anything about those. On an iPhone you may use the book on any Apple device you own or control, as the App Store’s usage rules allow. Apple and its subsidiaries are third-party beneficiaries of these terms and may enforce them against you.
What you are allowed to do with it. While your subscription is current you get a personal, non-exclusive, non-transferable, revocable licence to use the book for your own work. What that covers — and the things it does not — is set out in 20.7.
What you must not do.
- Share, sell, rent, sub-licence or give away your access or your sign-in.
- Show a personal plan to a class or group on a projector, a TV or a shared screen, by mirroring, casting, streaming or any other way. A class needs a school licence (20.7).
- Copy, republish or redistribute the book or a substantial part of it, in any form, including reformatted or retyped.
- Scrape, crawl, bulk-download, or extract the tables or entries by any automated means.
- Use the book or any part of it to train, fine-tune, evaluate or ground a machine learning model, or to build a competing product.
- Get round, disable or interfere with any access control, or reverse engineer the software except where law says you may.
- Strip out or alter any copyright, trademark, source or disclaimer notice.
The book is a reference, not an engineering document. This is the important one and it has its own entry: 20.8. In short — it does not replace your job specification, drawings, codes, manufacturer data, training, qualifications or supervision, and where it disagrees with the governing standard on your job, the standard wins. You verify every figure before you cut, lift, hang, weld or test anything.
Availability and changes. We aim to keep the book up and correct, and we add to it and fix it over time. We do not promise it will be uninterrupted or error-free. Entries may be added, corrected, reorganised or withdrawn — corrections are the point of a living reference. If we ever make a change that removes something substantial you paid for, you may cancel, and nothing more is charged after that. Payments already made are not refunded (20.4).
What you send us. Send in a correction, a photograph, a figure from your shop or a suggestion and you keep owning it, but you grant us a worldwide, royalty-free, perpetual licence to use it in the book and in material about the book. Do not send anything confidential to your employer or your customer, or anything you do not have the right to send. Credit is given where you want it and withheld where you do not — say which.
Other people's material. Standards, manufacturer catalogues and regulations referred to here belong to the bodies that publish them, and are named so you can go to the source. Trade marks belong to their owners (20.9). Links or references to anything outside the book are not endorsements.
Suspension and termination. You can stop any time by cancelling. We may suspend or end access if you breach these terms — seriously or repeatedly — and where it is fair to do so we will tell you first and give you a chance to put it right. If we end your access for something that was not your fault, you get the unused part of your term back.
Warranty disclaimer. THE BOOK IS PROVIDED "AS IS" AND "AS AVAILABLE", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, ACCURACY OR NON-INFRINGEMENT.
Limitation of liability. To the fullest extent the law allows, we are not liable for any indirect, incidental, special, consequential or punitive loss, or for lost profit, lost work, rework, delay, scrap material or downtime, however caused. Our total liability arising out of or relating to the book is limited to the amount you paid us in the twelve months before the claim. Nothing in these terms excludes or limits any liability that cannot lawfully be excluded or limited — including for death or personal injury caused by negligence, for fraud, or under consumer protection law that applies to you.
Indemnity. You will cover us against claims arising from your use of the book in breach of these terms, or from work you performed, to the extent the claim is caused by that breach.
Disputes and governing law. These terms are governed by the law of Ohio. Any dispute is decided by the state or federal courts located in Cuyahoga County, Ohio, and both of us agree to those courts. Nothing here takes away a right you have under the consumer law where you live.
Changing these terms. We may update these terms. For any change that materially affects you, we will give at least 30 days notice by email before it takes effect, and you can cancel before then if you do not accept it. Carrying on after the date is acceptance. Every version is dated, and previous versions are available on request (20.11).
The rest of it. If a clause is unenforceable the rest still stands. Not enforcing something once does not waive it. You may not transfer this agreement; we may transfer it as part of a sale of the business, on notice to you. These terms, together with 20.4, 20.6, 20.7, 20.8 and any separate signed agreement described above, are the whole agreement between us about the book.
Getting hold of us. [email protected], or the postal address in 20.11.

What gets collected, why, who touches it, and how to get it deleted.

The short version

Your email and your payment go to running your subscription. The card number never touches our systems — the payment processor holds it. Nothing is sold, nothing is shared with advertisers, and nothing tracks you. The website counts visits only as totals, with no cookies and nothing that identifies you. On a crew or class licence, the people running it see the work you do for it, listed below. Students aged 13 to 17 use it only through a school, program or employer licence, and a school stays in charge of its students’ records. Ask and it all gets deleted.

Effective November 8, 2026 · Controller: Pipelogic LLC, 850 Euclid Ave Ste 819 #7312, Cleveland, OH 44114 · Questions: [email protected]

What is collected, and why

What	Why	Kept for
Email address and name	To give you an account, send receipts, renewal reminders and correction notices	Until you delete the account
Your progress and saved things, when you are signed in	Which self-paced lessons you finished, your best and latest score on each and the questions you still have missed, your saved and recently opened pages, the notes you write on pages, your cut lists and job folders (job names, cut lists and job notes; job photos stay on the phone that took them), your best practice quiz scores, and your settings (text size, light or dark, glove mode and the like), so the website and the app on each of your devices show the same ones. If you turn on phone alerts in the app, we keep that phone's alert address (from Apple or Google) with your email so a crew or class hand-out can reach it; signing out takes it off. Alerts are sent through Google Firebase Cloud Messaging and say only what was handed out and by which crew or class. Only you see them; they are not shown to a foreman, instructor or admin. A certificate you earn carries the name you type and a check code, so anyone you show it to can confirm it on our site.	Until you delete the account
Your say messages (20.12), on the website	What you write, the page and the name or details you choose to add, plus your email if you are signed in, so we can write back. Only Pipelogic LLC reads them.	Until you ask us to delete them
On a crew, company, school or union hall licence	The licence’s admins, and the foreman or instructor who runs your crew or class, see your name, your email, when you last opened the book, and your practice quiz scores, with the questions you missed and the answers you picked, so they can manage seats and follow the crew or class. They also see which assigned pages you opened, the tasks and assignments you marked done, your lesson quiz scores and missed questions, the JSAs and toolbox talks you signed, the cut list pieces you sent to the cut man, and the photos of your work you add to a task or assignment. The crew’s cut man sees those pieces too. Nothing else about you is shown to them.	Until you are taken off the licence, when all of it is deleted, except the JSAs and toolbox talks you signed. Those stay with the licence as its safety record.
Subscription and payment records	To take payment, issue receipts and meet tax and accounting law	7 years, as the law requires
Card details	Never held by us. In the app: Apple (iPhone) or Google (Android) holds the card and we never see any of it. Web: entered directly with Stripe, who is PCI compliant, and we see the last four digits and the expiry	Held by Apple, Google or Stripe, not us
Support emails, corrections, suggestions and stories you send	To answer you, to fix the entry you told us about, and — only where you said yes — to share your story with the name you chose	3 years
Photos and files added on a crew or class dashboard	Prints, drawings, photos and documents a foreman, instructor or admin adds to what they hand out or to the Prints tab, and photos of your work you send back on a task or assignment. Only people signed in on that licence can open them, and only the people it was handed to see them in their list. Photos are made smaller on your phone before they are sent, which also takes out the camera’s location. We never look at them or use them for anything else.	Until the person who added it, or the foreman, instructor or admin, deletes it, or deletes what it is on. Your own work photos are deleted when you are taken off the licence.
A map pin, if a foreman or instructor taps “Pin where I am now”	So the crew gets directions to a jobsite with no street address. It is the spot the foreman’s phone reports at that moment, saved with the task, JSA or talk they hand out. Nobody’s location is tracked otherwise.	As long as that task, JSA or talk is kept on the licence
Visit counts on the website	Cloudflare Web Analytics counts which pages are opened, the site that linked to them (such as a Facebook post or a Google search), the country, and the kind of device and browser, so we can see what brings people in. It sets no cookie, stores nothing on your device, does not fingerprint you and keeps nothing that identifies you. The iPhone and Android apps do not count visits at all.	Only as totals, never tied to you
Basic technical logs (IP, device, browser, time)	Security, fraud prevention and keeping the thing running	90 days
Your settings — theme, text size, language	So the book opens how you left it	On your device only; never sent to us. Email preferences (reminders, update notes) are kept with your account so they can be honoured.

There is no advertising identifier and no behavioural profiling. The only analytics is the website’s visit count in the table above. If that ever changes, this table changes first and you get told.

Who else touches it

Only suppliers who need it to run the service, under contract, and only for that purpose:

Stripe — takes the payment and holds the card details.
Apple and Google — take the payment when you subscribe in the iPhone or Android app, under their own privacy policies.
RevenueCat — tells the app whether a subscription bought through Apple or Google is active. It gets a random ID for the app on your phone, basic details of the phone and app version, and the store’s record of the purchase. It never gets your name or email.
Google Firebase Cloud Messaging — delivers phone alerts to the app when you have turned them on. It gets your phone’s alert address and the alert itself (what was handed out and by which crew or class). It never gets your email.
Cloudflare — serves the app and the website, and counts visits to the website as totals (see the table above).
Supabase — holds your account: your email address, your sign-in and your plan status, and the crew or class work in the table above, including its photos and files.
Resend — sends sign-in codes and update notices. Stripe sends receipts and renewal reminders.

If a partner's link brought you here, that partner sees that a plan was bought through it, which plan, the date and the amount, so they can be paid their share. They never see your name, email or anything else about you.

Nothing is sold, rented or shared for anybody's advertising. Data may be disclosed if the law requires it, or transferred as part of a sale of the business — in which case you get told first.

Your rights

Wherever you live, you can ask to see what is held, correct it, delete it, get a copy to take elsewhere, or object to a use of it. Email [email protected] and it will be actioned within 30 days, free, and using the service will not get worse because you asked.

California (CCPA/CPRA): the rights above, plus the right not to be discriminated against for using them. We do not sell or share personal information, and we do not use it for cross-context behavioural advertising — so there is nothing to opt out of. Categories collected are in the table above.
EU and UK (GDPR): our legal bases are performance of the contract (running your subscription), legal obligation (tax records) and legitimate interests (security, keeping the service up). You may complain to your supervisory authority.
Deleting your account erases your email, name and settings. Payment and tax records are kept for the period the law requires and then erased.

Students and children

Field Fitter is for people learning or working in a trade. Students aged 13 to 17 can use it only through a seat on a licence from their school, training program, union hall or employer. It is not directed at children under 13, and accounts are not knowingly created for them. If we learn that an account belongs to someone under 13, it is deleted. Write to [email protected] if you believe that has happened.

School licences and student records

When a school or training program gives a student a seat, the school stays in charge of that student’s records. Under FERPA, the federal student privacy law, we act for the school as a “school official” and handle those records only to run Field Fitter for its class:

Student records are used only to provide the book, the class dashboard and what the instructor sees, as the table above lists.
They are never sold and never used for advertising, and they are never used to build a profile of a student for anything outside the class.
The school can ask at any time to see, correct, export or delete its students’ records, and it is done within 30 days. A parent, or a student who is 18 or older, should ask the school, and we help the school answer.
When the licence ends, the school can ask for its students’ class records to be deleted, and they are deleted within 30 days.
Where the school has signed a student data privacy agreement with us, it applies as well, and it wins wherever it differs from this policy.

Security

Everything travels encrypted. Access to account data is limited to people who need it. Card data never reaches us. No system is perfect — if a breach affects you, you get told, and any regulator that must be told gets told, within the time the law sets.

Storage on your device

The book keeps your settings in your browser's own storage on your device. That is not a tracking cookie, it is not sent anywhere, and clearing your browser data clears it. Signing in sets one cookie that keeps you signed in. It is strictly necessary for the account to work and is not used for tracking. If you arrive through a partner's link on the website, a second cookie holds that partner's code for 60 days so they get credit if you subscribe. It holds nothing about you, and clearing your browser data clears it.

Where the data sits

Held in the United States. If you are outside it, your data is transferred there under the safeguards the law requires, such as standard contractual clauses.

Changes

If this policy changes in a way that matters, you get an email at least 30 days before it takes effect. The date at the top always tells you which version you are reading.

Who owns what is in here, what you are free to do with it, and the short list of things that will get your access pulled.

The short version

Use it on your own phone, your tablet and your laptop. Screenshot a page and show the hand next to you. Do not post the book, sell it, or feed it to a machine. If your whole crew needs it, there is a crew licence that costs less than each of them subscribing.

What is actually owned here

A dimension out of ASME B16.9 is a fact, and nobody owns a fact. What is owned is everything built around them:

The writing — every explanation, worked example, tip and warning.
The drawings, diagrams and the step-through walkthroughs.
The way the book is organised: material-first sections, the cut rules, the selection, arrangement and presentation of the tables.
The calculators and the code behind them.
The name, the look and the marks.

Copying the arrangement and the expression is infringement even where the underlying numbers are not owned by anybody.

What your subscription lets you do

Use the book on the devices you personally use — phone, tablet, laptop, shop computer. A personal plan stays signed in on up to three of them at a time; signing in on a fourth signs the oldest one out.
Screenshot a page and send it to a hand on your job, put it on a job whiteboard, or show it to your foreman. That is what it is for.
Quote a line or a figure in your own work — a cut list, an RFI, a toolbox talk — with credit to Field Fitter.
Teach from it in your own apprenticeship class, so long as each student has their own access or the class is licensed (below). Putting one personal plan up on a projector or TV for the class is not that: the app covers a personal plan while the phone is mirrored.

What it does not let you do

The short list

Share your login. Project or cast a personal plan to a class. Post the book, or whole sections of it, anywhere. Sell, rent or bundle it. Retype the tables into your own document, app or spreadsheet for distribution. Print it and hand it out. Scrape or bulk-export it. Use it to train, fine-tune or ground a machine learning model. Strip the notices off it.

These are not nitpicks — they are the whole reason the book can keep being written and corrected.

Crews, shops and schools

If more than a couple of people need it, licence it properly rather than sharing a login. Crew and company licences come with one bill, priced per seat, and let a foreman add and remove hands as the crew changes. Each seat is for one named person at a time. Apprenticeship programs, schools and union training centres pay by invoice. The admin runs the licence without needing a seat. A foreman or instructor who runs their own crew or class takes one. Details and prices: fieldfitterapp.com/licenses, or write to [email protected].

If somebody is copying it

Send it to [email protected] — a link, a screenshot, wherever you saw it. That helps more than you would think.

If you think this book copies you

Notice under the Digital Millennium Copyright Act goes to the designated agent:

DMCA Agent, Pipelogic LLC, 850 Euclid Ave Ste 819 #7312, Cleveland, OH 44114, [email protected]

A valid notice needs: your signature (electronic is fine), what work you say was copied, where in this book it appears (give the entry number), your contact details, a statement that you believe in good faith the use is not authorised, and a statement that the information in the notice is accurate and, under penalty of perjury, that you are the owner or authorised to act for them. Material that is the subject of a valid notice gets removed promptly, you get told, and you may file a counter-notice. Repeat infringers lose their accounts.

The most important page in the legal end of this book, and the one worth actually reading. It is the same message as 12.11, written so it holds up.

Read this once, properly

Field Fitter is a field reference. It is not a code, a standard, an engineering document, or professional advice, and it is not a substitute for any of them.

It does not replace your job specification, your drawings, your engineer, your foreman, your employer's safety program, your training or your own judgment. Nothing in it authorises or instructs you to perform work you are not trained, qualified and permitted to do.

Where this book and the governing standard, code, specification or manufacturer's data on your job disagree, the governing document wins. Every time. No exceptions.

Engineering decisions are not yours to make from a phone

Reinforcement, blind and closure thickness, support and anchor design, guide spacing, rigging plans, lift plans, test pressures, pipe sizing and anything touching a pressure boundary are engineering functions. This book explains what they are and how the math works so that you understand what you are building and can spot when something looks wrong. It does not qualify you to make those calls, and using it that way is outside what it is for.

Rigging and lifting

Section 25 (Rigging) is general, basic-to-intermediate reference. It is not rigging training, it is not a lift plan, and it does not qualify, certify or authorise anyone to rig, signal or direct a lift. Rigging and signalling must be done by persons trained and qualified for the work, and certified where the employer, owner, jurisdiction or contract requires it, following the site lift plan, the employer's program and the equipment manufacturer's instructions. Pipelogic LLC accepts no responsibility for any lift, rigging arrangement, load or outcome, and nothing in the book may be relied on in place of a qualified rigger's judgment.

Figures change, and vary

Standards are revised. A figure that was right at the edition named in an entry may not match the current edition your job runs to.
Manufacturers differ. Grooved, press, olet, valve and gasket dimensions vary by brand, size and schedule — the maker's catalogue governs.
Codes are local. Hanger spacing, grade and drainage rules change by jurisdiction.
Fittings vary in the box. Check the first one out of every box against the figure you are using.
Typographical and computational errors are possible in any reference, this one included. Report them (20.11) and they get fixed fast.

What you take on by using it

You accept that you are responsible for verifying every figure against the governing standard, specification, code and manufacturer data for your job before you cut, weld, lift, hang, pressurise or test anything, and for working within your training, your qualifications, your employer's program and the rules of your site. If you are not sure, ask somebody who is. Piping work is dangerous work and no reference can make it safe for you.

Warranty and liability

THE BOOK IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND ACCURACY.

To the fullest extent the law allows, Pipelogic LLC is not liable for any loss, damage, injury, rework, scrap, delay or downtime arising out of the use of, or reliance on, anything in this book, and total liability will not exceed what you paid in the twelve months before the claim. Nothing here limits any liability that cannot lawfully be limited, including for death or personal injury caused by negligence, for fraud, or under consumer protection law that applies to you.

Full terms: 20.5. Sources and standards: 12.11 and 20.9.

Where every number came from, whose names appear in here and why, and what the book is built out of.

Where the numbers come from

The full source table — which standard governs which figure, and where a maker's catalogue governs instead — is in 12.11. It is worth reading before you rely on a table for anything that matters.

Standards and rules referenced, by the group that publishes them:

ASME: B1.1, B1.20.1, B16.1, B16.3, B16.5, B16.9, B16.10, B16.11, B16.20, B16.25, B16.47, B16.48, B30.2, B30.5, B30.9, B30.10, B30.14, B30.16, B30.20, B31.1, B31.3, B31.4, B31.8, B31.9, B36.10M, PCC-2 and Boiler and Pressure Vessel Code Section IX.
AWS: A2.4, A5.1, A5.4, A5.12, D1.1, F2.2; ANSI Z49.1.
API: 5L and 1104.
NFPA: 13, 13R, 13D, 14, 25, 51B, 54 and 72.
Federal rules: OSHA 29 CFR 1910.28, 1910.146, 1910.147, 1910.184, 1910.252, 1910.253, 1926 Subparts L, M, R and AA, 1926.453, 1926.1053 and 1926.1408; DOT pipeline safety 49 CFR 192 and 195; EPA refrigerant rules 40 CFR 82 (Section 608).
Plumbing and mechanical codes: the International Plumbing Code, International Mechanical Code and International Fuel Gas Code (ICC); the Uniform Plumbing Code (IAPMO); the 2010 ADA Standards for Accessible Design and ICC A117.1.
Materials and products: MSS SP-43, SP-58 and SP-95; CISPI 301; ASTM A135, A795, D2466, F876, F877, F1807, F1960, F2080, F2098 and F2159; ASSE 1001, 1010, 1011, 1013, 1015, 1016, 1020, 1024, 1056, 1061 and 1070; ASHRAE 34 refrigerant safety groups; UL 60335 for A2L equipment; SMACNA duct practice.
Other: ISO 2553 weld symbols; IEC 60825-1 and ANSI Z136.1 laser safety.
Maker’s data quoted by name: Spears Schedule 40 PVC fitting dimensions; Lincoln Electric and Hobart electrode storage and filler choices; Chemours pressure-temperature tables for R-134a and R-404A; OSHA’s eye-protection fact sheet for lens shades.

Each standard is the authority for its own figures, and this book is not affiliated with, endorsed by or licensed by ASME, AWS, API, MSS, ASTM, ASSE, ASHRAE, ICC, IAPMO, CISPI, OSHA, DOT, EPA, NFPA, UL, SMACNA, ISO, IEC, ANSI or any other body. Nothing here reproduces a standard — individual facts are stated with the source named, which is what a standard is for. Each entry names its own source, and the edition on your job is the one that counts.

Trade marks

Trade names appear because they are what people say on the job. They are used only to identify those companies' products, under nominative fair use. This book is independent — not affiliated with, authorised by, sponsored by or endorsed by any of them, and no claim is made to any of these marks.

Mark	Owner
Weldolet®, Sockolet®, Thredolet®, Elbolet®, Latrolet®, Nipolet®, Sweepolet®	Bonney Forge Corporation
Victaulic®	Victaulic Company
Teflon®	The Chemours Company
ProPress®, Viega®	Viega LLC
NIBCO®	NIBCO Inc.
Anvil®	ASC Engineered Solutions
Shurjoint®	Shurjoint Piping Products
Victor®	ESAB Group Inc.
Harris®	The Harris Products Group / Lincoln Electric
Spears®	Spears Manufacturing Company
Freon™, Opteon™	The Chemours Company
Sawzall®	Milwaukee Electric Tool Corporation

All other marks are the property of their respective owners. Where it can, this book uses the generic name — butt weld outlet, grooved coupling, PTFE tape — because that is what you order by.

What the book is built out of

Component	Licence
Type	Your phone’s own system fonts. Nothing is bundled or downloaded.
Everything else — layout, calculators, diagrams, walkthroughs	Written for this book. No frameworks, no libraries, no trackers.

The book is one file, and once it is on your phone it works with no signal. No advertising network, no analytics package, no trackers. That is a deliberate choice: it is what lets the whole thing work in a basement, and it means there is nothing in here quietly watching you work. On the website, Cloudflare, which serves it, counts visits as totals with no cookies and nothing that identifies you (20.6); the phone app counts nothing.

It goes online only for your account: signing in, paying, and the crew and class dashboards. Those calls go to our own server at fieldfitterapp.com, which uses Supabase for sign-in, Resend to email sign-in codes, Stripe for card payments on the website, and Apple or Google (through RevenueCat) for payments in the phone app. More on what is stored, and where, is in the privacy policy (20.6).

Credits

Written by Pipelogic LLC. Corrections and field knowledge contributed by the fitters who sent them in — named here where they wanted to be, as they come in.

A book you cannot read is not a reference. Here is where this one stands and what is still wrong with it.

The target

WCAG 2.1 Level AA. That is a goal being worked toward, not a certification — and the gaps below are listed honestly rather than quietly.

What is already in place

Text scales to three sizes without breaking any layout or table (20.2).
Light and dark are both drawn to hold contrast, not inverted from one another.
Nothing depends on colour alone — every warning, tip and formula carries a written label as well as a colour.
Every diagram carries a text description for screen readers, and every walkthrough step is written out in words, not just drawn.
Keyboard navigation works throughout, with a visible focus outline on every control.
Motion stops if your device asks for reduced motion.
Tap targets meet the minimum, and Gloves mode makes them considerably bigger.

What is not right yet

Text follows your phone’s own text-size setting (switch it off in 20.2 if you prefer the book’s own sizes). It is applied as a scale, so a very large phone setting can push wide tables sideways.
Wide dimensional tables scroll sideways on a phone, or open full screen with the header row pinned. The full-screen view is still a table, and a screen reader reads it as one.
The animated walkthroughs are visual by nature. Each step's text stands on its own, but the geometry is easier to follow if you can see it.
No full audit by a third party has been done.

Hit a barrier?

Tell me and it gets fixed

Write to [email protected] with the entry number and what went wrong. You get an answer within 5 working days, and if it cannot be fixed quickly you get the information you needed another way in the meantime.

Who to write to, about what, and how long it takes to get an answer.

Support and corrections

Found a number that is wrong?

Send the entry number, what you got, and what you expected. A take-out that does not match your catalogue, a formula that does not close, a practice answer that comes out different, or a habit from your shop that belongs in here. Corrections go in fast and you see them the next time you open the book. This book gets better because fitters say where it is wrong — that is the whole arrangement.

[email protected]

Answered within 2 working days. Safety-related corrections are looked at the same day.

Everything else

About	Write to
Billing, refunds, cancelling	[email protected] — though cancelling is faster in 20.4
Privacy, data access or deletion	[email protected]
Copyright and DMCA	[email protected], see 20.7
Crew, shop and training licences	[email protected]
Accessibility barriers	[email protected], see 20.10
Legal notices and service of process	The postal address below — email is not valid service

The company

Entity: Pipelogic LLC, an Ohio limited liability company
Address: 850 Euclid Ave Ste 819 #7312, Cleveland, OH 44114
Registered agent: Republic Registered Agent LLC, 850 Euclid Ave, Ste 819, Cleveland, OH 44114
Governing law: Ohio

Notices

To you: by email to the address on your account, and by a notice inside the book for anything that affects everybody. It is your job to keep that email address current.
To us: for anything legal, in writing to the postal address above.

Disputes

Any dispute about the book or your plan is decided by the state or federal courts located in Cuyahoga County, Ohio, under Ohio law (20.5). Nothing here takes away a right you have under the consumer law where you live.

Version history

Document	Version	Effective
Terms of Service (20.5)	1.2, adds buying in the iPhone and Android apps	October 17, 2026
Terms of Service (20.5)	1.1, lets students aged 13 to 17 use a seat from their school, program or employer	October 8, 2026
Terms of Service (20.5)	1.0	October 5, 2026
Privacy Policy (20.6)	1.7, keeps your lesson progress, saved pages, notes, cut lists, job folders, settings and best scores on your account, adds phone alerts, and adds certificates	November 8, 2026
Privacy Policy (20.6)	1.6, adds visit counts on the website	October 18, 2026
Privacy Policy (20.6)	1.5, adds Apple, Google and RevenueCat for subscriptions bought in the app	October 17, 2026
Privacy Policy (20.6)	1.4, adds photos and files on crew and class dashboards	October 13, 2026
Privacy Policy (20.6)	1.3, adds how school licences handle student records	October 8, 2026
Privacy Policy (20.6)	1.2, adds the quiz questions you missed to what leaders see	October 7, 2026
Privacy Policy (20.6)	1.1, adds what crew and class leaders see	October 7, 2026
Privacy Policy (20.6)	1.0	October 5, 2026
Copyright and licence (20.7)	1.0	October 5, 2026
The book itself	October 2026 edition	October 14, 2026

Superseded versions are kept and made available on request — you are entitled to see the terms you actually agreed to on the day you agreed to them.

This book gets better because the people using it say where it falls short. A page you wanted and could not find, a better way your shop does it, the job you will never forget, or a plain complaint — send it. Every one gets read.

What is it?

Which page? (optional) Tell us

About you — all optional

First name or nickname Trade Years in the trade Local, shop or state

What happens to it

Suggestions and wrong numbers go on the list for the next update, and anything that gets changed shows up in What changed. Complaints get read first. Stories and shout-outs are only ever shared if you picked yes above — and you can change your mind any time by writing back.

Your draft is kept on this phone until you tap Start over, so you can come back to a long one. What you send is covered by 20.5 section 10 — you keep owning it — and by the privacy policy in 20.6.

The rest of this book is the standard and the math. This section is the part nobody writes down — the tricks, habits and hard lessons working hands pass to the next one, with their names on them.

Every tip here comes from someone in the trade who sent it in and said yes to sharing it. Nothing is made up and nothing is ghost-written. If a tip is here, a real fitter, welder, plumber or steamfitter stands behind it.

What a tip looks like

[The tip, in the words of the person who sent it — what the job was, what they do, and why it works.]

— [First name] · [Trade] · [Years in] · [Local, shop or state][page it goes with]

Credit reads exactly the way the sender chose in 20.12: first name and trade, or “a pipefitter in Ohio” with nothing that points to them.

How a tip gets in

Send it through Your say and pick Trade tip. Say which page it goes with if you know.
A journeyman reads it before it goes in. A tip that could get someone hurt, fail a test or break a code does not go in, however good the story.
It goes in with your name — or without it — the way you said, and shows up in What changed. The page it belongs to gets a link back here.

A tip is not a procedure

These are the ways good hands work, not the rule. Where a WPS, the job spec, the code or the manufacturer says something different, they win — every time (20.8).

The tips

More are on the way. The questions going out are in 21.2 — answer any of them and you could be next.

The questions going out to working hands for this section. Pick any one, answer it the way you would at lunch, and send it.

Short is fine. A page number helps. Tell us your trade and years if you want the credit.

Starting out

What is the one thing you wish somebody had told you your first year?
What did a journeyman show you that you still use every week?
What should every apprentice have in their bag that is not on the tool list?

Measuring and cutting

How do you check a fitting or an end is square without a square?
What is your trick for marking pipe so the mark survives the torch or the grinder?
How do you make sure your cut list is right before a single piece gets cut?
What is the fastest way you know to get a take-out off a fitting that is not on any chart?

Fit-up and welding

How do you set and hold a gap that every welder on the crew is happy with?
How do you keep a spool from pulling when it gets welded out?
Welders: what do you wish every fitter did before handing you a joint?

Offsets, layout and the field

How do you field-check a rolling offset before you weld it?
What is your shortcut for a saddle or a lateral when there is no time to lay it out?
What is the mistake you have seen cost the most money on a job, and how do you avoid it?

Rigging, safety and being a hand

What is the rigging habit that has kept you or your crew out of trouble?
What is the one thing about safety a new hand does not take seriously enough?
What makes a hand the one the foreman asks for by name?

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Cross-linked polyethylene tubing for hot and cold water and radiant heat. It bends around corners, so a PEX job is laid out with fewer fittings than copper — and every fitting you leave out is a joint that can never leak.

PEX-A: Cross-linked while it's still soft (the Engel method). The most flexible. Kinks can be heated back out, and it's the tubing the cold-expansion fittings are built for.
PEX-B: Cross-linked after it's formed (silane method). Stiffer, holds its shape, usually cheaper. Crimp, clamp or press fittings. A kink gets cut out, not heated.
PEX-C: Cross-linked with an electron beam. The stiffest. Same fittings as PEX-B.

Color is not the type

Red, blue and white are the same tubing. Color is only there to tell hot from cold. The type (A, B or C), the standard and the pressure rating are printed on the side every few feet — read the print, not the color.

Ratings on standard PEX water tubing

Water temp	Pressure rating
73°F	160 psi
180°F	100 psi
200°F	80 psi

The standard hydrostatic ratings for PEX water tubing (ASTM F876/F877). They're printed on the tubing. Heating-only and oxygen-barrier PEX may be rated differently, so go by what the print says.

Sizes

Water PEX is copper tube size (CTS), SDR 9. The outside diameter matches copper tube of the same nominal size, which is why push fittings and some transitions fit both. The wall is thicker than copper, so the bore is smaller. The numbers are in 22.2.

Keep it out of the sun

UV breaks PEX down. Leave it in the box or the bag until you use it, and never run it exposed outdoors. The print or the maker's sheet says how many days of sunlight it can take during construction. That's often only 30 days, and some makers allow less.

Heat and chemicals

Keep it clear of flue pipes, recessed lights and anything else that runs hot. The maker lists clearances. Most makers, and many local codes, want the first 18" off a water heater to be metal. Never bury PEX in soil soaked with fuel or solvents, because they go right through it. PEX water tubing is never used for fuel gas.

Sources: ASTM F876 (PEX tubing); the tubing maker’s data.

SDR 9, copper tube size. The OD is fixed and the wall is 1/9 of the OD, with a floor of .070" on the small sizes.

Nominal	OD	Min wall	ID (approx)	Gal / 100 ft
3/8"	.500	.070	.360	0.53
1/2"	.625	.070	.485	0.96
3/4"	.875	.097	.681	1.89
1"	1.125	.125	.875	3.12
1-1/4"	1.375	.153	1.069	4.66
1-1/2"	1.625	.181	1.263	6.51
2"	2.125	.236	1.653	11.15

OD and minimum wall per ASTM F876 (SDR 9, CTS). The ID column is worked from the minimum wall, so real tubing runs a hair smaller. Gallons per 100 ft is worked from that ID.

Why 3/4" PEX isn't 3/4" copper

3/4" type L copper has about a .785" bore. 3/4" PEX has about .681". That's roughly a quarter less flow area. On a long run, or on a manifold feed, that's why the PEX is often sized up one.

How long until hot water gets there

Gallons in the line ÷ faucet GPM = minutes of waiting. A 50 ft run of 1/2" PEX holds about 0.48 gal. At a 1.2 GPM lav that's about 24 seconds of cold water before the hot arrives. The same run in 3/4" is about 47 seconds. That's the case for home runs in 3/8" and 1/2" to the far fixtures.

Sources: ASTM F876 (CTS SDR 9 dimensions).

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Drain, waste and vent. Water runs downhill by gravity. The trap holds a plug of water that keeps sewer gas out of the room. The vent lets air in behind the water so it doesn't suck that plug out on its way past.

The trap seal is the water between the trap's weir and its dip, 2" to 4" deep. The trap arm runs from the weir to the vent. Keep it short and at a steady grade so the vent opening never ends up below the weir. The vent keeps the pressure in the pipe equal to the air in the room.

The parts, by name

Fixture drain: Trap outlet to where it joins another drain. The trap arm is the part of it between the weir and the vent.
Branch: A horizontal drain collecting several fixtures.
Stack: A vertical drain running through one or more floors. Soil stack takes toilets; a waste stack takes everything else.
Building drain: The lowest horizontal drain inside the building. Everything ends up here.
Building sewer: From where the building drain ends (30" outside the wall under the IPC, 2 ft under the UPC; some local codes go farther) to the public sewer or septic.
Stack vent: The drain stack carried on up through the roof above the highest fixture.
Vent stack: A separate vertical vent run beside a drain stack. It relieves pressure on tall buildings.

What goes wrong without a vent

Siphonage. A slug of water rushing past pulls a vacuum behind it and sucks the trap dry. The room smells like sewer.
Back-pressure. Water falling down a stack pushes air ahead of it, which blows through traps lower down as bubbles and gurgling.
Slow drains. The water has to push air out of its way. Glugging sinks are almost always venting.

Your code

This section teaches the International Plumbing Code (IPC) and the Uniform Plumbing Code (UPC) and says where they differ. Ohio and West Virginia both build on the IPC; much of the western US uses the UPC. Every state and city amends its code. The code adopted where you're working, and the inspector, govern over anything in this book.

Sources: IPC chapters 7 and 9; UPC chapters 7 and 9.

Water has to turn gently where it's moving fast or running flat. That one idea picks nearly every DWV fitting.

Change	Use	Don't use
Horizontal → vertical	Sanitary tee, wye, combo (wye + 1/8), 1/8 bend, 1/4 bend	— (most fittings work here: the water is falling)
Vertical → horizontal	Long sweep, combo, wye + 1/8 bend, two 1/8 bends	Sanitary tee. Short sweep in small sizes.
Horizontal → horizontal	Wye, combo, long sweep, 1/8 bends	Sanitary tee. Short 1/4 bend.

The pattern both codes follow (IPC Table 706.3, UPC 706). Each code has size limits and exceptions in its own table. The short sweep, for instance, is allowed vertical-to-horizontal from 3" up under the IPC.

San tee: The branch comes in with a short curve. It's for a horizontal line dropping into a vertical one, and it's what the trap arm hits on the stack. Never lay one on its back.
Wye: A 45° branch. With a 1/8 bend on the branch it makes the turn in two easy steps.
Combo: A wye and 1/8 bend cast as one fitting (a "combination wye and 1/8 bend" or "tee-wye"). Shorter than the two pieces.
Long sweep: A 90 with a long radius. It's the go-to for turning a stack to horizontal.
Closet bend: A 90 under a toilet. It turns the floor flange into the horizontal drain.

Back-to-back fixtures

Two fixtures on opposite sides of a wall, draining into one vertical pipe. A double sanitary tee can't take back-to-back toilets, or fixtures that pump their water out, like washers and dishwashers (IPC 706.3). Use a double fixture fitting or a double combo. Check the table for the fitting in your hand.

The pitch is built in

Most DWV sanitary tees, wyes and 1/4 bends are made with 1/4" per foot of grade built into the branch, so the branch isn't a true 90 (or, on a wye, a true 45). Set the fitting square and the branch runs out at grade. It's why a line at 1/8" per foot fights the fittings a little, and why you roll them slightly to match.

Sources: IPC Table 706.3 and UPC 706 (fittings for change of direction).

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Every card in this trade sits behind a test. This section tells you what's on each one, how it's scored, what books you can bring, and then lets you practice until the answers come without thinking.

Test	Who runs it	What it's like
Union apprenticeship entrance	Your local's JATC (training committee)	Aptitude test: math, mechanical reasoning, spatial and sometimes reading. Usually no calculator, no books. Scores are ranked. Read 24.5.
NCCER Pipefitting	Trade schools, open-shop contractors, assessment centers	A written test after every module (70% to pass) plus hands-on performance checks. A 125-question journey-level assessment. Read 24.9.
Ohio contractor license	Ohio Construction Industry Licensing Board (OCILB), tested by PSI	A trade exam (plumbing, HVAC, hydronics or refrigeration) plus Business & Law. Open book, 70% to pass. Read 24.2.
West Virginia contractor license	WV Contractor Licensing Board, tested by Prov	A trade exam (piping, plumbing, HVAC and others) plus Business & Law. Open book, 70% to pass. Read 24.3.
WV journeyman or master plumber	West Virginia, by hours of experience and an exam	8,000 hours for journeyman, 12,000 for master, plus an exam for each card. Read 24.3.

How to work this section

Read the page for your test. Get the current candidate bulletin from whoever gives the exam. The bulletin is the rulebook, and it changes.
Get the reference books it lists. Buy the edition it names, especially for code books.
Take the practice quiz for your test cold, before studying. What you miss is your study list.
Follow the plan in 24.10. Retake the quizzes until you clear 85%, because the real test is harder than practice.
A week out, take the timed mixed test (24.16) to practice working against the clock.

Check before you schedule

Question counts, time limits, fees and book lists here come from the candidate bulletins as they read in September 2026 (Ohio: PSI bulletin updated February 2024; West Virginia: Prov bulletin of September 2024). Boards change vendors, books and code editions. If the bulletin you're sent says something different, the bulletin wins.

About the practice questions

Every practice question in this book was written for Field Fitter. None of them are copied from a real exam. Sharing real exam questions breaks your agreement with the test vendor and can cost you your license. These questions teach the same material, with the reasoning shown after each one.

Sources: NCCER; state exam bulletins.

Ohio licenses commercial plumbing, HVAC, hydronics, refrigeration and electrical contractors through the OCILB. To get one you pass two exams: your trade and Business & Law.

Before you can sit

At least 18 years old.
Five years working in that trade right before you apply. The application asks for proof: tax records, permits pulled under a licensed contractor, or your journeyman card.
After the board approves you, a BCI and FBI background check, then you schedule with PSI. The approval is good for one year.

The exams

Exam	Questions	Time	Pass
Business & Law	50	2 hr	70%
Plumbing	100	4 hr	70%
HVAC	100	4 hr	70%
Hydronics	50	2.5 hr	70%
Refrigeration	60	3 hr	70%

Plus up to 10 unscored "pretest" questions that count against your time. You can't tell which ones they are, so answer everything.

What's on them

Plumbing: General knowledge 8 · General regulations 20 · Fixtures 6 · Water supply 10 · Drainage, waste & vents 24 · Indirect wastes 3 · Roof drains 4 · Specialty 5 · Isometric analysis 20
HVAC: General 10 · Warm air heating & air distribution 25 · Ventilation & exhaust 15 · Air conditioning 10 · Piping 10 · Equipment & appliances 20 · Testing 10
Hydronics: General knowledge 16 · Heating equipment 10 · Piping, pumps, valves 10 · Fuel gas & oil 1 · Venting 5 · Controls 5 · Tests 3
Refrigeration: General 18 · Refrigeration piping 12 · Refrigerants 6 · Systems & controls 15 · Testing 9
Business & Law: Business organization 2 · Licensing 3 · Estimating & bidding 8 · Contracts 5 · Project management 4 · Insurance & bonding 5 · OSHA record keeping & safety 5 · Personnel 5 · Financial management 6 · Tax 5 · Lien law 2

Books you can bring

Plumbing: Ohio Plumbing Code 2024 · International Fuel Gas Code 2024 · Mathematics for Plumbers and Pipefitters, 8th ed. · Modern Plumbing, 9th ed.
HVAC: Ohio Mechanical Code 2024 · International Fuel Gas Code 2021 · Modern Refrigeration and Air Conditioning, 22nd ed.
Hydronics: Ohio Admin. Code 4101:4 (boiler rules) · Ohio Mechanical Code 2024 · Boiler Operator's Guide, 4th or 5th ed.
Refrigeration: Ohio Mechanical Code 2024 · Modern Refrigeration and Air Conditioning, 22nd ed.
Business & Law: NASCLA Contractor's Guide to Business, Law and Project Management – Ohio. The test center provides this one.

You can highlight, underline and tab your own books ahead of time. You can't write notes in them or bring loose papers. PSI gives you an on-screen calculator, and it's the only one allowed.

Where the points are

On the plumbing exam, 44 of 100 questions are DWV and isometrics. If you can size a drain and read an iso, you're close to halfway there already. Isometrics are practice, not memorizing: work every iso problem in the math book. Section 23 of this book covers the DWV side.

Money, retakes, locations

$69 per exam, each time you take it.
Fail a part and you wait 60 days to retake it. Up to 5 tries a year.
Pass Business & Law and it covers any other trade license you add within three years.
PSI sites in Ohio include Cambridge, Groveport (Columbus South), Dublin (Columbus North), Akron, Cleveland, Hamilton, Macedonia, Maumee, Troy and Wadsworth.

Journeyman cards in Ohio

Ohio has no statewide journeyman plumber or fitter card. Some cities license journeymen themselves; Columbus is one. Ask the building department where you work.

Sources: Ohio Construction Industry Licensing Board (OCILB) and PSI candidate bulletins.

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A refrigeration system moves heat. It boils refrigerant where you want heat taken out and condenses it where you want heat dumped. Four parts do the work: compressor, condenser, metering device, evaporator.

The basic loop. Copper = high side (compressor out to metering device). Black = low side (metering device out to compressor in).

How the cycle runs

Step through it

Simplified drawing of how it works, not any one brand; the numbers are examples.

The four parts

Compressor: Pulls low-pressure vapor off the evaporator and squeezes it into hot, high-pressure gas. It is a vapor pump. Liquid coming back to it (floodback or slugging) breaks valves and scrolls.
Condenser: Hot gas gives up heat to outdoor air or water. It desuperheats, condenses to liquid, then subcools a little before leaving.
Metering device: Fixed orifice (piston, cap tube) or valve (TXV, EEV). Drops the pressure so the liquid can boil cold in the evaporator. This is the dividing line between high side and low side.
Evaporator: Cold liquid boils as it picks up heat from the air or load. By the outlet it should be all vapor and a few degrees superheated.

Saturation is the key idea

Where liquid and vapor are both present (inside the coils), pressure and temperature are locked together. Know one and the PT chart gives you the other. That is why a gauge reading tells you the boiling temperature in the evaporator and the condensing temperature in the condenser.

Raise the pressure and the boiling point goes up. That is how the condenser can dump heat to hot outdoor air.
Drop the pressure and the boiling point goes down. That is how the evaporator gets colder than the room air.
Vapor warmer than saturation is superheated. Liquid colder than saturation is subcooled. Those two numbers are how you judge the charge (26.4).

Line names in the field

Discharge line: Compressor to condenser. Hot gas. On a split system it is usually inside the outdoor unit.
Liquid line: Condenser to metering device. The small line of a line set. Warm to the touch in cooling.
Suction line: Evaporator to compressor. The big line of a line set. Cool and sweating in cooling. Insulate it.

Heat pumps

A heat pump runs the same loop backward in heating. The reversing valve swaps which coil is the condenser. The indoor coil condenses and the outdoor coil evaporates. The big line carries hot gas in heating mode.

Sources: Standard refrigeration cycle theory.

A PT chart gives the saturation temperature for a gauge pressure. It only applies where liquid and vapor are both present: inside the evaporator and condenser, not in superheated vapor or subcooled liquid.

How to read it

Confirm the refrigerant from the unit data plate. Never go by the color of a jug or a guess.
Read the gauge in psig. Most charts are psig at sea level. Readings below 0 psig are vacuum, shown in inches of mercury ("Hg).
Find the pressure in the refrigerant's column and read the temperature on that row. Digital manifolds do this for you if you set the right refrigerant.
For a blend with glide, pick the right column: dew for the suction side, bubble for the liquid side.

Dew, bubble and glide

Single component: R-22, R-32, R-134a. One temperature for each pressure.
Near-azeotropic blend: R-410A, R-404A. Glide is small. R-410A is normally printed as one column.
Zeotropic blend (glide): R-454B, R-407C and others. At the same pressure the blend starts to boil (bubble point) cooler than it finishes boiling (dew point). The difference is the glide.
Dew point: Temperature where the last drop of liquid boils off (100% vapor). Use it for superheat.
Bubble point: Temperature where the first bubble forms (100% liquid). Use it for subcooling.

Why: superheat is measured on vapor leaving the evaporator, so compare it to where the refrigerant just finished boiling (dew). Subcooling is measured on liquid leaving the condenser, so compare it to where it just finished condensing (bubble).

Worked — same temperature, two pressuresR-454B at 40°F on the table in 26.3:
Dew = 107.0 psig. Bubble = 112.0 psig.
Use the wrong column and your superheat or subcooling is off by a couple of degrees. Suction side: dew. Liquid side: bubble.

Chart limits

Charts are for sea-level atmosphere. At high elevation a gauge reads higher for the same absolute pressure; use an elevation-corrected chart or a gauge that corrects. Also check the chart edition from the refrigerant or equipment manufacturer when numbers matter.

Gauge check

With a system off and fully equalized in steady weather, the pressure should match the PT value for the ambient temperature. A reading well above that points to non-condensables or the wrong refrigerant.

Sources: Refrigerant makers’ pressure-temperature tables (Chemours).

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A sprinkler system is a grid or tree of pipe full of water (or air) with heat-operated heads. Know which type you are on before you open a valve or cut a pipe.

How each system trips

Step through it

Simplified drawing of how it works, not any one brand; the numbers are examples.

Each head opens on its own

A standard head has a glass bulb or fusible link holding a cap over the orifice. Heat breaks the bulb or melts the link. Only the heads over the fire open. The rest stay shut.

That is why a leaky head or a bumped head floods one spot, not the whole building. It is also why a busted head on a wet system flows until someone shuts the control valve.

The four main types

Type	Pipe holds	How it trips	Where you see it
Wet pipe	Water under pressure	Head fuses, water flows at once	Heated buildings. Most common and simplest.
Dry pipe	Air or nitrogen under pressure	Head fuses, air bleeds off, dry valve opens, water fills pipe	Unheated areas: parking decks, loading docks, attics, freezers.
Preaction	Air (often supervised)	Detection system opens the valve first; heads still must fuse	Data rooms, museums, freezers: places where accidental water is costly.
Deluge	Nothing; heads are open	Detection opens the valve; every head flows	High-hazard spaces: aircraft hangars, some chemical and power plant areas.

NFPA 13, Standard for the Installation of Sprinkler Systems. The 2022 edition is widely adopted; a 2025 edition is out. The edition your AHJ adopted, plus local amendments, is the one that governs.

13, 13R, 13D

NFPA 13: Full commercial standard. Property and life protection. Everything in this section is based on 13 unless noted.
NFPA 13R: Low-rise residential (apartments, dorms). Life-safety focused. Lets some spaces go unsprinklered. The building code sets the height limit.
NFPA 13D: One- and two-family dwellings and manufactured homes. Simplest rules. Often run in CPVC or PEX by plumbers or fitters.

Dry and preaction pipe is not empty

A dry system holds compressed air or nitrogen. A tripped dry system is full of water. Before you break a joint, confirm the valve is shut, the system is drained, and the air is bled to zero on the gauge.

Impairments

Shutting a control valve takes the building's protection out. Follow the owner's impairment procedure: notify the owner, the monitoring company and usually the fire department. Put it back in service the same day if you can.

Sources: NFPA 13, 13R and 13D.

The riser is where the water supply enters the system. Every riser has the same jobs: shut off, stop backflow, signal flow, drain, and let the fire department pump in.

Typical wet riser, supply at the bottom. Trim layout varies by valve maker: follow the valve's data sheet.

What each part does

Control valve: Indicating valve (OS&Y gate, butterfly, or PIV outside). Must show open or shut at a glance. Keep it open, and supervised, locked, or sealed.
Tamper switch: Supervisory switch on the control valve. Sends a supervisory signal when the valve is moved off full open.
Alarm check valve: Check valve with an alarm port. Stops water flowing back to the supply. On a wet riser it can also drive a water motor gong or pressure switch.
Flow switch: Vane in the pipe. Water movement pushes the vane and sends the waterflow alarm. Has a built-in delay (retard) so pressure surges do not false alarm.
Gauges: Supply gauge below the clapper, system gauge above. The system reading is usually higher, because the check traps surge pressure.
Main drain: Drains the system and is used for the main drain test (see 27.11). Pipe it to a place that can take full flow.
FDC: Fire department connection. Lets the pumper boost the system. Ties in on the system side of the riser check or alarm valve, through its own check valve. No shutoff valve in the FDC line.
Inspector's test: Valve and orifice at the far end of the system that flows like one head. Used to prove the waterflow alarm works.

Main drain size

Riser or main size	Main drain size
Up to 2 in	3/4 in or larger
2-1/2 in to 3-1/2 in	1-1/4 in or larger
4 in and larger	2 in

NFPA 13 (2022) Table 16.10.4.2. Auxiliary drains for trapped sections: see 16.10.5.

Trapped sections

Wet pipe does not need pitch, but every trapped low spot still needs a way to drain. On a wet system: over 50 gal trapped, a 1 in valve; 5 to 50 gal, a 3/4 in valve; under 5 gal, a 1/2 in plugged nipple. On dry pipe in cold areas, a trapped section of 5 gal or more gets a drum drip: two 1 in valves with a 2 in × 12 in condensate nipple between them.

Sources: NFPA 13.

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The test position decides where you're allowed to weld in production. Pass the wrong position and you're qualified, but not for the job in front of you.

New to welding?

Start with the basics on plate at 28.13: beads, pads, fillets, the backing-strip test and open root in every position.

The four pipe groove test positions. The copper band is the weld. Only 1G gets rolled; 5G and 6G stay fixed and you go round them.

Watch each test position

Step through it

Simplified drawing of how it works, not any one brand; the numbers are examples.

What each pipe test covers

Test	How the pipe sits	Groove positions qualified
1G	Axis horizontal, rolled, weld on top	Flat
2G	Axis vertical, weld runs level around it	Flat, horizontal
5G	Axis horizontal, fixed	Flat, vertical, overhead
6G	Axis at 45°, fixed	All
2G + 5G	Two coupons, both passed	All

ASME Section IX Table QW-461.9, pipe groove tests. A groove test also qualifies fillet welds (QW-303.1). The table has more columns — plate, pipe over 24" OD, fillets — so read it for anything outside plain pipe butt welds.

5G alone is not all-position. It misses horizontal. Add a 2G, or take the 6G.
A plate test does little for small pipe. Plate groove tests mostly qualify plate and very large pipe. Check QW-461.9 before you assume a plate cert covers a pipe rack.
Fillet tests qualify fillets only. A 2F or 4F plate test never qualifies you for a groove weld.
6GR is a 6G with a restriction ring set close to the joint. It's an AWS D1.1 structural test for tubular T-, Y- and K-connections — not the usual mechanical-piping test.

Fillet positions

1F: Flat. The fillet is laid in the trough, weld axis level.
2F: Horizontal. One plate flat, one standing up, weld runs level.
3F: Vertical. Weld runs up (or down) the joint.
4F: Overhead.
2FR / 5F: Pipe fillets — rolled horizontal, and fixed horizontal.

Uphill or downhill is its own variable

On 5G and 6G, which way you travel in the vertical matters. A test run uphill doesn't qualify you to run downhill, and the reverse. Pipeline work is the usual downhill case — see section 29.

Sources: ASME Section IX (QW-461 positions); AWS D1.1.

One code tells you how to qualify. Another tells you how to build the pipe. The paperwork ties you, the procedure and the job together.

Which code does what

Code	What it covers	Where you meet it
ASME Section IX	How welders and procedures get qualified	Your pipe test, almost every mechanical job
ASME B31.1	Power piping — design, fabrication, inspection	Boiler external piping, power plants, steam
ASME B31.3	Process piping	Refineries, chemical, pharma, many industrial plants
ASME B31.9	Building services piping	Commercial HVAC, chilled and heating water, steam in buildings
AWS D1.1	Structural steel — its own welder tests	Supports, structural steel, tubular frames
API 1104	Pipelines and related facilities	Cross-country and distribution lines — see section 29

The B31 piping codes set how the system is built and inspected, and they send you to Section IX for welder and procedure qualification. Check which edition the job spec and the AHJ adopted.

The three papers

WPS: Welding Procedure Specification. The recipe you weld to. It gives ranges — rod, amps, preheat, thickness, material — and you have to stay inside them.
PQR: Procedure Qualification Record. The proof the recipe works. It records what was actually used on a test weld and the lab results. You rarely see it, but the WPS must reference one.
WPQ: Welder Performance Qualification. Your record. It shows what you welded, how it was tested, and the ranges you're now qualified for. Also called a WQR or "your cert".

The WPS qualifies the procedure. The WPQ qualifies you. You need both, and they have to line up with each other and with the joint.
Your WPQ belongs to the organization that tested you. Under Section IX the employer is responsible for its welders' qualifications. A new employer can accept a previous one's test only where the code and the owner allow it.
Position isn't a WPS variable. A procedure qualified in 1G can be written for all positions. Position is a welder variable — it lives on your WPQ.

Get a copy

Ask for a copy of every WPQ you sign and keep them together with your continuity records. When a job asks "what are you certed for?", the answer is on that paper, not in your memory.

Sources: ASME Section IX; AWS D1.1; API 1104; ASME B31.1, B31.3 and B31.9.

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A spread is a moving factory. Each crew does one job, then the next crew comes behind. If one crew falls behind or does sloppy work, every crew behind it pays for it.

The order of work

Survey and staking. Centerline, ROW edges, foreign line crossings and bends get staked.
Clearing and grading. ROW cleared and leveled so equipment can travel. Topsoil is often stripped and kept separate for restoration.
Ditching. Trencher or excavators dig to the depth the drawings call for. Foreign lines are located and exposed by hand or vac.
Stringing. Joints are hauled out and laid end to end along the ditch on skids.
Bending. Bending crew makes field cold bends to match the survey at sags, overbends and side bends.
Line-up and root. Front-end crew lines up joints with a side boom and clamp. Stringer bead (root) and hot pass go in.
Firing line. Fill and cap welders finish the welds behind the front end.
NDT. Welds are X-rayed or UT'd. Rejects are repaired or cut out.
Field joint coating. Bare weld areas are blasted and coated. Whole pipe is holiday tested ("jeeped").
Lowering in. Side booms lift the string off the skids and set it in the padded ditch.
Tie-ins. Tie-in crew welds the sections together at road bores, crossings and gaps.
Backfill. Padding first around the pipe, then the rest of the spoil.
Hydrotest. Sections are cleaned, gauged, filled, pressured and held. Then dewatered and dried.
Cleanup and restoration. Topsoil back, grade restored, fences and drainage fixed.

Who does what

Union pipeline work in the U.S. runs under the National Pipe Line Agreements. Four crafts are party to them.

Craft	Typical work on the spread
UA (pipeliners)	Welders and welder helpers, line-up, fitting, tie-ins.
Operating Engineers (IUOE)	Side booms, excavators, dozers, trenchers, bending machine.
Laborers (LIUNA)	Skids, coating, swamping, grade work, general labor.
Teamsters	Pipe haul, stringing trucks, fuel and water trucks.

Craft split varies by agreement, job and region. Your steward and the job's pre-job conference settle who does what.

Front end sets the pace

The front end (line-up, stringer, hot pass) sets how many welds get made each day. The firing line and every crew after it are sized to keep up with them.

Sources: Common pipeline practice; API 1104; 49 CFR 192.

Pipelines in the U.S. are regulated by the federal DOT through PHMSA. The CFR rules are law. The ASME and API standards are the technical rulebooks those laws point to.

Document	What it covers
49 CFR Part 192	Federal rules for natural gas and other gas pipelines: design, welding, construction, testing, operation.
49 CFR Part 195	Federal rules for hazardous liquid pipelines (crude, refined products, etc.) and CO₂.
ASME B31.8	Industry code for gas transmission and distribution piping.
ASME B31.4	Industry code for liquid and slurry pipelines.
API 1104	Welding of pipelines: procedures, welder tests, inspection, and weld acceptance standards.
API 5L	Line pipe: grades, chemistry, strength, dimensions, testing.

49 CFR 192.7 incorporates API 1104 21st ed. (2013, with errata and addenda), API 5L 46th ed. (2018) and ASME B31.8-2018. API published the 22nd ed. of API 1104 in 2021. Your operator's spec names the edition for your job.

How they fit together

192.225 says weld procedures must be qualified under API 1104 or ASME Section IX.
192.241 says weld acceptability is judged by API 1104 section 9 (or Appendix A).
The operator (pipeline owner) writes specs that are often stricter than code. On the job, the operator's spec wins as long as it meets code.

Operator Qualification (OQ)

OQ rules are in 192 Subpart N (gas) and 195 Subpart G (liquids). They make sure people doing certain tasks on an operating pipeline have been evaluated.

Covered task: Meets all four: done on a pipeline facility, is an operations or maintenance task, is required by the regs, and affects the operation or integrity of the pipeline.
Evaluation: How the operator checks you can do it: written or oral test, work performance history, observation, or simulation.
Qualified: You can do the task and can recognize and react to abnormal operating conditions (AOCs).
AOC: A condition that may mean equipment is failing or the system is outside design limits, or is a hazard to people or property.

An unqualified person may do a covered task only if directed and observed by a qualified person.
PHMSA says OQ does not cover new construction. But the tie-in of a new line to an existing one is an O&M task, and so is work on that segment after tie-in.

49 CFR 192.801–192.809; 195.501–195.509; PHMSA OQ FAQs.

Carry your OQ cards

If you are not qualified on a covered task, do not do it unless a qualified person is directing and watching you. Operators audit this.

Sources: 49 CFR 192 and 195; API 5L (46th ed.); API 1104 (22nd ed.); ASME B31.4 and B31.8.

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New to the book, or can't find something? Start with the tour. Each tutorial below walks you through the real screens one step at a time. Tap Next to move on, or Done to stop.

Answers by topic

Moving around the book: 30.2
Searching: 30.3
Saved pages and recently viewed: 30.4
Tables, drawings and walkthroughs: 30.5
Calculators and the cut list: 30.6
Your trade, settings and working offline: 30.7
Practice quizzes and test prep: 30.8
Your plan, billing and cancelling: 30.9
Common questions: 30.10
Something wrong, or still stuck: 30.11

The book is split into numbered sections, and each section into numbered pages. 1.3 is page 3 of section 1. Every link in the book uses those numbers.

The bar along the bottom

Home: Your materials, then your sections on short shelves. Tap Home any time to start over.
Charts: Every table in the book on one page (0.1). The fastest way to a take-out or a trig constant.
Calc: Fourteen calculators and your cut list (13.1).
Lessons: The self-paced lessons: the book one lesson at a time, with a short quiz on each. They come with the full book.
Class: Your class dashboard: assignments, scores and lesson plans. It shows once you are signed in with the email your instructor added.
Crew: Your crew dashboard: tasks, training, JSAs and the cut list. It shows once you are signed in with the email your foreman added.
Saved: Pages you saved, then the pages you opened lately.

To search, tap Home and use the box at the top.

The Back button

Top left of every page. It always takes you to the page you were on before, and back to the same spot on it. Keep tapping to walk back through where you've been. Home on the bottom bar starts fresh.

Inside a section

Open a section and you get its list of pages. Pages marked "inside" hold more pages under them, such as the advanced fab pages under 1.15.
At the bottom of every page, Previous and Next step through the section in order.
A blue number in the text, like 13.1, is a link. Tap it to go there, and Back to come back.

The search box on Home searches every page title, keyword and paragraph in the book. Type what you'd say out loud.

What works

Type	Finds
A size: 6", 6 inch, 6in	All the same to search.
Trade words: rolling, fishmouth, sil-fos	The page that covers it.
A number: 1.414, B31.3, R-410A	Constants, codes and refrigerants.
Two or three words: copper 90 take out	Every word has to land somewhere on the page, so more words narrow it down.
A typo: brazimg	Search forgives one wrong letter in longer words.

Nothing came up?

Try fewer words, or the plain name of the fitting or job.
Try the Charts page for tables, or the section list on Home.
Still missing? Tell us what you searched for (30.11). A search that finds nothing is how we learn what to add.

Tap ★ Save at the top of any page and it goes on your Saved list. Tap it again to take it off.

Saved on the bottom bar shows your saved pages first, then the pages you opened lately, newest first.
On the Saved list, the ↑ moves a page to the top and the × removes it.
Up to 24 saved pages and the last 15 you opened are kept.
Saved pages are kept on this phone. A new phone, or clearing the browser's data, starts the list over.

Most answers in the book are a table, a drawing or a step-through walkthrough. Each one can be opened up bigger.

Wide tables: Swipe sideways to see the rest of the columns, or open the table full screen with the header row held at the top.
Highlighted cells: The key number in a table is shaded, such as the 40°F row of the PT chart or the limit you can't go past.
Take-out tables: In the fitting tables (1.11), tap a size and the cut length calculator opens on that fitting.
Drawings: Tap any drawing to see it full screen, then close it to go back to the page.
Walkthroughs: Pages marked GUIDE in a section list have a step-through walkthrough built in. Step forward and back at your own speed. They work with no signal.
Jump buttons: Long pages open with a row of buttons under the title. Tap one to go straight to that part of the page.

Calc on the bottom bar opens the fraction calculator, full screen on a phone. Tap All calculators for the grid of all fourteen and your cut list, and tap any one to open it. Change order lets you move the ones you use most to the top, and Calc then opens whichever is first. Show all info puts the fraction calculator back in the page, with the tape drawing, Round to nearest and how to type a number. Every one shows its math underneath, so you can check it by hand.

Typing measurements

Type it the way you say it: 18 1/2, 18-1/2 and 18.5 all work.
Where a box asks for feet and inches, use both boxes. Leave feet blank for a short piece.
Conversions (tab 4) takes a fraction, a decimal, feet and inches, decimal feet or metric, and gives you all of them.

The cut list

Work out a piece in the cut length or offset calculator.
Tap + Add to cut list. It gets the next piece mark, and a box opens to name the part (like "riser to pump"). Type a name and tap Save name, or tap Skip. You can rename it later on the list.
Open the Cut list tab to see every piece. The tab shows how many pieces are on it.
Send it to the saw as a text or a link. Whoever opens the link sees the same list.
Clear it when the spool is done. It stays on this phone until you do.

Check the first one

Calculators use the book's standard take-outs. Fittings vary by maker and in the box, so check the first fitting out of each box against the number you're using.

The book is set up for the trade you picked the first time you opened it. You can change that, and the look of the book, any time.

Your trade

The book asks the first time you open it. To change it later, use Your trade in Settings (20.2). If you are signed in, your account remembers it on every phone. Your materials and sections move to the top. Nothing is taken out of the book, and "Whole book" puts it back the way it was.

Settings worth knowing

Theme: Auto, light or dark. Dark is easier at night, light in direct sun.
Text size: Follows your phone's size, then scales up from there.
Gloves mode: Makes every button and list row big enough to hit with a glove on.
Keep the screen awake: Stops the screen going dark halfway through a cut list.

No signal

Every table, calculator and walkthrough runs on your phone, so once the book has opened with signal it keeps working with none, even closed and opened again. Signing in, buying or changing a plan, your crew or class page, and sending anything — a message to us, quiz scores, a cut list — need a connection. On a crew or class seat, open it with signal at least once a day; after that it opens with only the free pages until it gets signal again.

Scored practice quizzes are at the end of the Test Prep section (24) and the HVACR, Sprinkler Fitting, Welding and Pipeline sections (26 to 29).

Tap Start. Pick an answer and you see right away whether it's right, and why.
70% passes. Aim for 85% before the real test.
The timed mixed test (24) pulls questions from all the licensing and apprenticeship quizzes, against the clock, like the real thing.
Section 24 also covers what's on each exam and gives an eight-week study plan. Start there if you're preparing for a license or an entrance test.

Open Test Prep

Some pages are free for everyone. The rest of the book opens with a plan.

Free for everyone: the first 2 pages of every section, all of the account and legal pages (20), and this Help section.
A locked page shows the plans when you open it. Nothing is charged until you choose one: $8.99 a month, or $75 a year with the first 7 days free the first time.
To cancel, switch plans or update your card, open Your account and tap Manage or cancel your plan. You keep access until the end of the period you already paid for.
Billing, refunds and failed payments are all explained in 20.4.

The questions people ask most, with short answers.

Is this a code book?: No. It's a field reference. Your job spec, the code your area adopted, your drawings and the maker's data always win (20.8).
My fitting doesn't match the take-out in the book.: Fittings vary by maker, and grooved, press and PVC take-outs come from maker catalogs. Measure your fitting and type it into the calculator yourself. If a standard fitting is off, report it (30.11).
Does it cover my state's code?: The plumbing pages cover the IPC and UPC side by side, and the license prep covers Ohio and West Virginia so far. Local amendments change things, so check what your area adopted.
Where do the numbers come from?: Published standards and maker data, named under each table and listed in 20.9.
How do I know what changed?: Every version is listed on the What changed page, including every corrected number. A banner on Home tells you when there's a new one.
Is it in Spanish?: Spanish is being written by Spanish-speaking fitters, not machine translated. When it's ready it shows up in Language (20.3).
Can I use it for rigging?: As a reference only. Rigging is done by trained, qualified people under the site's lift plan. Read 25.1.
Can I share a page with my crew?: You can send a cut list as a link. For anything else, see what you may and may not copy in 20.7.

If a number looks wrong, a page is missing, or something in the app doesn't work, tell us. Every message gets read.

A wrong number: open the page and tap Report a wrong number on this page near the bottom. The page number goes in for you.
An idea, a missing topic, or a question this section didn't answer: tap Suggest something for this page, or use Your say (20.12).
Billing or account trouble: see Contact (20.11).

Help us help you

Say what page you were on, what you tapped, and what you expected to happen. A screenshot is even better.

Working the table itself

What kind of number you are looking at

Between two rows

Centre to centre: the most common dimension on prints

Take-out, in detail

The words, and what each one points at

Why weld pipe has no add-back

What you measure and mark with

Where the tape actually goes

Measuring off a square end

Taking a field weld measurement

Habits that keep field measurements honest

Couplings

Unions

Socket depth — PVC Sch 40, nominal

Coupling gap

The end prep that matters

Laying out cast iron

Cutting

No-hub couplings

Hub and spigot

What the sides are called on the job

Rules that beat the table

Getting it right

Qualified and certified are not the same thing

When the rules say it has to be a qualified person

What this section is good for

When it is required

The three parts, and all three have to be good

The numbers, and why they are what they are

Wearing it, and checking it

Offset calculator

Cut length calculator

Cut list

Notes for this job

Photos for this job kept on this phone

Fraction calculator

Conversions — fractions, feet and metric

Pipe weight and fill

Flow, velocity and pipe size

Volume and fill time

Grade and fall

Right triangle solver

Circumference and equal divisions

Thermal expansion

Sling angle and leg load

Temperature, pressure and head

Fab layout

What is in your hand

The three reference marks

Which conduit

The four steps — every layout in this section

Two rules that save every layout

What goes where

What each column is for

NPT thread data

Wrench makeup — how far past hand tight

Thread types you'll meet

Wrench across flats

Pipe wrench to pipe size

Drill sizes for pipe taps

Tap drill sizes — machine threads

Decimal → fraction

Fraction → decimal

The whole tape, to 64ths

Inches and eighths → decimal of a foot

The ones worth knowing cold

Five tracks, in this order

Three habits that make the math easy

The function keys — angle in, ratio out

The inverse key — ratio in, angle out

The other keys you will use

A whole rolling offset, keystroke by keystroke

A fitting

An assembly

Where a dimension is measured to

Positions around the pipe

How the marks work

Always reduce

Feet and inches