Pipefitter Math Made Clear: Offsets, Rolling Miter Cuts and Take-Outs, Worked Step by Step, with Field Tables the Check Behind Every Number

The travel is 15 9/16". The cut is 10 5/16". Now check it before the saw touches the pipe.A cut piece of pipe is thirty seconds of saw time and twenty minutes of rework. This book is about getting the number right the first time, and about the thirty-second check that proves it - with a tape and a framing square, on the layout table, before anything is committed.The geometry was calculated by one program and independently checked by a second. The second one does not know the first one's formulas: it rebuilds the pipe run as vectors in space, adds them, and measures where the far end lands. Across every worked example the two close on each other to better than a ten-trillionth of an inch. Figures printed as tape fractions are rounded separately to the nearest sixteenth, and manufacturer-dependent dimensions are marked as values to confirm on the fitting.What is inside - The four numbers - offset, run, travel, take-out - and the one sentence that ties them together - Simple offsets at every fitting angle, with the constants and where they come from - Rolling offsets taken apart one piece at a time: the true offset, the travel, the roll angle, and the mark you put on the pipe - Cut elbows, mitered bends, and a 90 made from two 45s - Wrap-around templates: angle cuts, ordinates, fish mouths, laterals and header holes - Four complete jobs worked start to finish, including the one nobody writes about - what to do when the spool measures half an inch out and you have to find which number lied - Reading an isometric, setting flange bolt holes, and the offset an eccentric reducer puts in your line - Twelve reference tables at the back, and an index built from the real page numbers How it is writtenEvery chapter opens on a job, works it in plain language, shows the drawing, and closes with a check you can do in thirty seconds. Thirty-eight chapters, thirty-three dimensioned figures, and no chapter that needs the one before it if you are standing at the pipe with a problem.What it does not doIt does not replace the job drawings, the line specification, the welding procedure or the code. Where a dimension comes from a catalog rather than from geometry, this book says so and shows you how to get it off the fitting in thirty seconds. One table came out of the book entirely: three catalogs gave three different answers, so Chapter 4 shows you how to take that dimension off the fitting with a straightedge and a tape.For pipefitters, steamfitters, welders, sprinkler fitters, apprentices, and anybody who has to turn a drawing into a cut length.