XPipe Pro
Pipefitter's calculator
Offsets, rolled elbows, cuts and layout — worked out to the millimetre and drawn to scale, on the pipe you are actually holding.
No ads. No tracking. No account. Everything works offline.
Try the maths
This is the app's own arithmetic, running here in the page. Change anything and the drawing and the figures follow.
With the fittings closed up this offset is the most the two radii can make.
What is inside
Two half elbows in one plane, with or without an insert. Tick what you know — angle, offset, length or insert — and the sketch shows live what will be worked out. Four new combinations, including the insert from the length and the angle from an insert already cut.
A 90° elbow rolled about the inlet axis — the offset is always up Z.
A run across X, Y and Z. Both elbow angles are solved separately, because they differ — and the box you measure is drawn round the pipe, not round the theoretical corners. The headline figure is the insert between the two elbows — the pipe you actually cut.
Cutting an elbow down to an odd angle: take-out, heel and throat arcs, chords, heights, and the arcs to mark back from the face you already have.
Purge time before the root pass, the gas it costs, and the inlet velocity that tells you the flow rate is wrong before the weld does.
How far to cut a reducer back so its end comes out at the diameter you need — with the offcut and the cut plane drawn.
The sector to strike on flat sheet for a full or truncated cone, with the sheet it fits on, its area and what the finished part holds.
Twelve pieces off one construction: round over square or square over round, centred, offset on one axis or on both, with the square opening level or laid over — and a round pipe run down into a square or rectangular pyramid. Each returns the blank to cut, the true length from every corner out to its quarter of the circle, and the angle the sheet turns at each of those lines. The pyramid pair returns two patterns, because it is two jobs: the hole in the faces and the fishmouth on the pipe.
Several lines making the same offset. Bend them all in one place and the spacing closes up on the slant; this says how far to hold each fitting back.
A bend built out of straight pipe. Every segment length, the angle to set the saw to, and the cosine wave to wrap round the tube to mark it out.
One pipe cut to sit on another, square or on the skew. The length to cut, the distance back from the face at 8, 16 or 24 stations round the girth, and the size, shape and position of the hole in the run. The deepest point of the cut changes formula as the branch lies down; the app knows where that happens.
The same joint with the two axes set apart, at any angle. Setting a branch across the run costs it its symmetry: the two horns stop matching, the deepest point of the cut wanders off the crotch, and the hole in the run needs both of its edges given at every station rather than one half-breadth. Each side is marked on its own, and an end view carries the centre distance — in elevation the offset lies along the line of sight and cannot be seen at all.
A tube cut to stand under a bend — the fishmouth again, with the run curved. The seat is a torus rather than a cylinder, so every figure comes off a different root: the length to cut, the ordinates round the girth, the height of the base plate, and the two angles at which the tube first touches the bend. Set it off to one side and the near and far horns stop matching, exactly as they do on an eccentric branch.
Per cent, mm per metre, one-in-something and degrees are four ways of writing one number. Type whichever the drawing used; the rest follow, with running levels down the line.
The steel, what is in it, the lagging and the cladding — per metre for the hangers and in total for the crane. Plus the flooded weight, which is what a sling is really chosen against.
The gauge is down eight bar this morning: a leak, or a cold night? Water barely compresses, so a stiff system moves about 2.6 bar per degree. Whatever the cooling does not explain comes back in litres.
ΔL for the actual grade, and the leg the movement needs. Held solid at both ends the stress is E·α·ΔT — over 400 N/mm² for stainless at 150 °C, and it does not depend on the length at all.
Cut the closing spool short, pull the ends together, weld. The run starts in tension and the nozzle sees half the reaction. The force it takes is worth reading first: thirty millimetres on a four-inch line is tonnes.
Klöpper, Korbbogen and ASME profiles — blank diameter, knuckle radius, straight flange and crown height, worked from the finished inside diameter. The three shapes hold different capacity off the same diameter, and the difference is in the numbers, not the eye.
Converts a to z and back, filler metal per metre of leg, and an intermittent weld’s length and pitch — with the callout read back in words, so a6 and z6 are never taken for the same joint.
V or J: the face width, the groove area and the filler a joint will take. On a heavy wall a J holds about half what a 60° V does, and the screen shows both so the saving is a number rather than a claim.
One butt weld is a millimetre and nobody notices. Twenty on a rack run is two centimetres and the last spool does not reach. Work it out before cutting, and calibrate the figure on your own first spool.
Two flanges, a gasket, washers, nuts and the thread that has to show. ASME B16.5 gives the thickness without the raised face below Class 400 and with it above — read it the same way for both and every low-class stud is 3 mm short.
Three criteria at once: bending, sag, and — on a line that has to drain — whether the sag tilts the pipe back uphill faster than the gradient takes it down. The last one is not in the tables, and it is the one that catches hygienic work.
B36.10M and B36.19M wall thickness by schedule number, in inches and millimetres together, with the bore that thickness leaves — so a schedule number off a spec sheet becomes a wall you can actually measure for.
ISO 7-1 / EN 10226 taper and parallel threads, R 1/16 to R 6: pitch, major and minor diameter, and the length of thread to cut — read off the size stamped on the fitting rather than guessed with a gauge.
EN 10253 / ISO 3419 dimensions for elbows, tees and reducers, DN 15 to DN 600 — centre-to-face and centre-to-end, the two figures a drawing gives and a spool sheet needs.
EN 1092-1, ASME B16.5 and the hygienic DIN 11853-2, drawn face-on beside the section — because the section gives you the thickness and the section alone never tells you where the holes go. Bolt circle, hole size, count and the chord between two neighbouring holes, which is how a pattern is checked with a calliper rather than a protractor.
Searchable pipe tables with short, long and orbital elbow data, plus every standard the trade quotes and the fittings each one defines.
The symbol sheet: 239 marks from ISO 6412, ISO 4067, ISO 14617, ISO 10628, ISO 2553, ISA-5.1, ASME Y14.38 and ASME Y14.44 — every one drawn, named and explained in a line. Search matches the lettering inside a symbol too, so BW, PIC or =G1 finds itself. One button drops the partition between standards, which is what an unknown mark actually needs.
Torque at the wrench, computed rather than copied off a table: stress area from the thread form, load from the grade and the share of yield you are pulling to, torque from the nut factor. The nut factor sits among the results with its own figure showing, because published values scatter by a third and everything downstream moves with it.
The wall a pressure needs under ASME B31.3 or EN 13480, the schedule it comes to, and a check of the pipe on the bench.
Arc energy from voltage, current and a timed run, and the preheat EN 1011-2 calls for.
Losses along the pipe and through its fittings by Darcy–Weisbach, and the size a velocity calls for.
Bend marks, gain, cut length and springback for a tube bender.
One pipe into two of the same size: the cut on all three pipes, as DXF or printed 1:1.
Whether a weld needs PWHT under ASME B31.3, at what temperature and for how long.
What an ISO 9606-1 or ASME IX certificate covers, and reminders before it lapses.
The only screen that measures instead of calculating. Lay the phone along a pipe and read the fall that is already there, in degrees, per cent, millimetres per metre or one in something. Zero it on a surface you trust and the reading cancels both the phone's own case and the crown of the pipe.
New in 1.9
An isometric of the line: route, valves, dimensions, cut list and a PDF sheet.
A direction, a length, the next direction. Elbows and tees place themselves from the geometry, and every symbol follows ISO 6412.
Every piece is cut short by what the fittings at its ends take off. Where a figure is missing, the piece is flagged rather than guessed.
An A4 or A3 PDF with the drawing, the bill of materials and the title block, ready to print and hand over.
A weld log on the isometric: every weld numbered on the sheet, with its welder, WPS, date, examination and status. Out to CSV, or to a PDF weld map.
An isometric out as a PCF for isometric software, and as a 3D DXF of the true centreline in plant coordinates.
Pick a length, then a direction — each press adds a run from the end of the line. The elbows follow from the turns; valves and branches go in with one tap.
Both go in the middle of the last run. Tap any point on the drawing to carry on from there.
The app adds every other valve and fitting, reducers, the cut list with take-outs, the weld log and the PDF sheet. Open this drawing in the app
On the phone
Not a diagram of something similar — a scale drawing of the exact assembly the numbers describe, dimensioned where a fitter would measure it.
Off the phone
A development is only worth having if it reaches the metal. The segmented elbow, the branch, the cone and the whole square-to-round family hand theirs over two ways, both at full size.
The blank as a real CAD file, drawn 1:1 — R12, which every reader still opens, from a nesting table's software to a current CAD seat. Cut line, fold lines, setting-out, seam and lettering on separate layers, so a machine can be given the outline alone. Curves go out sampled far finer than the marking-out stations; a cone leaves as true arcs.
Not every site has an A3 plotter, and every site has A4. The same pattern is broken across A4 sheets at full size with a map sheet showing what goes where. Trim on the marked line, butt the sheets cross to cross, and stick the template straight onto the plate. Sheets that would come out blank are never printed, and every sheet carries a printed rule — measure it, and a printer that quietly scaled the page is caught in seconds.
Why you can cut to it
84 542
cases run through two independently written engines — one in Swift, one in Kotlin — on every change, and diffed figure by figure. Most come out identical to the last bit; nowhere do the two disagree by more than one part in a million million.
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tests on the geometry itself: worked examples stepped off by hand, exact round trips of every inverse, and the identities that keep a drawing honest.
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strings, translated in full into twenty-four languages. A half-finished language is kept out of the picker rather than shown as English patches.
Plus a library of every standard the trade quotes for pipe, fittings and joints — what each one covers, and the fittings it defines.
Millimetres or inches, dark or light, twenty-four languages, and every figure readable at arm's length on a pipe rack.