Pipefitter Offset Calculator

Most offset calculators give you the travel and stop there. Travel runs centre to centre of two fittings, so you cannot cut it. This one subtracts the fitting take-offs and your weld gap, then gives you the length to mark on the pipe. INCHES AND FRACTIONS, NOT DECIMALS Type 151 5/16 the way you would write it on a scrap of cardboard. Tap a fraction rather than typing a denominator. Everything comes back in inches and sixteenths, or eighths, or thirty-seconds if that is how your shop marks. No decimals to convert in your head. WHAT IT WORKS OUT - Rolling offsets, with the roll angle so you know how far to turn the fitting - Simple offsets in one plane - Fixed run, for when the obstruction has already decided your run - Cut length, with take-offs and weld gap taken off - Travel, run and true offset alongside it WHEN THE RUN IS FIXED Sometimes you do not get to pick the fitting. Give it the run you actually have and it works out the angle that run needs, then names the nearest fitting you can buy and the run that one would take. It will not assume 45 and hand you a piece that does not fit. THE PART YOU CAN CHECK Every number here comes from trigonometry you can do on paper. The 1.414 you already know for a 45 is 1 divided by sin 45, and that is how the app gets there too. Take-offs come off the fitting radius. Where a size breaks that rule, and a 1/2" and a 3/4" long radius 90 are both 1-1/2" rather than what the formula predicts, it uses the published dimension. You can edit any of it. If the fitting in your hand measures different, use yours. THE ASSUMPTIONS STAY ON SCREEN Every answer carries the gap it used, in plain words: cut length assumes 1/8" butt weld gap both ends. That line travels with the cut when you send it to a welder. Butt weld gaps shorten the pipe and socket weld gaps lengthen it. The app subtracts one and adds the other. ON A JOB SITE It works with no signal at all. The buttons are sized for a gloved thumb, and the screen stays on while an answer is up. Dark in the plant, light outdoors, following whatever your phone is set to. Figures are estimates for layout. Check the fitting and the weld procedure before you cut.