AptoCalc workbench
Offsets and rolling offsets in feet, inches and fractions, drawn in 3D. Type 2 4 Offset, then Travel or Cut. 2nd Cut (or Why? beside an answer) shows the working.
Free for a limited time The full AptoCalc is open to everyone: every tool, plus full-size templates to print.
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Coming from another pipe calculator?
Most of it sits where your thumbs expect it:
- Angle, Offset, Run, Travel across the top. Type a number and press one to set it; press one with nothing typed to see the answer. Keep pressing Travel for the cut, take-out, gap, fitting angle and, on a cut-down elbow, the inside, centre and outside marks.
- Feet, Inch and / above the numbers: 1 4 Feet 7 Inch 1 / 2.
- 2nd down the left is the shift key; what it gives is printed small above each key. 2nd Offset is the root gap, 2nd Run the cutback, 2nd Travel the roll, 2nd Angle the take-out and cut marks, 2nd Size the elbow.
- Angle takes degrees (4 5 Angle) or a slope as a length (1 Inch Angle is 1″ per foot); press it again for the slope and the % grade.
- Stor and Rcl with 1–9 keep nine numbers. M+ keeps a running total: Rcl Rcl shows it, again the average, again how many.
- Conv does gallons, pounds, flow, pressure, torque, temperature, % grade and drop; 2nd Conv does degrees-minutes-seconds.
What's new here: Cut has its own key, and 2nd Cut shows the working step by step, drawn in 3D. The Tape keeps everything you did. Take-outs are steel butt-weld fittings (ASME B16.9); for anything else type your fitting's take-out and press 2nd Angle. The root gap starts at none unless your site's admin set one: type yours and press 2nd Offset.
Nothing here is guessed: every number used is in a box, and the shortcuts only fill a box you can change. Leave a box empty and anything that needs it waits for it.
Branch wraparound wrap it round the branch's outside, top edge square
Hole in the header wrap it round the header, centred on the branch's centreline
Marks for each line for a tape and soapstone
Print at 100% / Actual size (not "fit to page"). Before you cut anything, check the long bar at the top of the first sheet with your tape. Sheets overlap: trim on the ✂ line, match the ✛ marks, tape, then check the rulers read true across the joins.
Miter wraparound top edge at the throat (the short point), square to the pipe
Marks for each line
Print at 100% / Actual size. Check the long bar on the first sheet with your tape, trim on the ✂ lines, match the ✛ marks, tape, then check the rulers. Wrapped on the pipe, the two line 0s must meet.
Template
Marks
Print at 100% / Actual size. Check the long bar on the first sheet with your tape, trim on the ✂ lines, match the ✛ marks, tape, then check the rulers.
The joint in section to the sizes you typed, one side of the pipe
Joints
Practice
Glossary the trade words, in plain English
Use the boxes instead
Stock take-outs are ASME B16.9 centre-to-ends, checked against two makers' charts; outside diameters are ASME B36.10M. Flanges (ASME B16.5 and B16.47 Series A and B) and pipe walls (ASME B36.10) are entered from two independent charts each; anything they disagreed on is left out. Bolting is the standard cross pattern and textbook torque maths: your job's procedure and the gasket maker's numbers govern. Every answer comes from the formulas shown under Why?, and the maths is tested before every update. Check the fittings you've actually got against their tags. Free to use; see Privacy & terms.