Finding new take-off for cutting down fittings.

Date 05-23-2009 22:45

We've been making several PIs and I'e been able to use 5' pups on all my fittings that I've had to cut down to a specific degree. On one of my last tie-ins, I wasn't able to use a pup because the other side was already welded to the pipe. What is the formula for finding the new take off for a fitting (90,45, etc.) after its been cut down. I know you can hold the fitting up to the joint and mark your cut, but it did raise the idea of WHAT IF YOU COULDN'T!

By swsweld (****)

Date 05-24-2009 01:52 Edited 05-24-2009 01:55

RockerB,
This won't help you with your immediate problem but I use this book for what you are describing.
http://www.pipefitters.com/
Pipe Trades Pocket Manual is the book that I'm referring to. Click books and look for A104. It gives the cut back ordinates and the center to end dimension for cutting down 90 elbows and it has lots of other prefigured charts that are very helpful. You don't have to go through the formula process the book gives you the numbers and they work very well.
This is my favorite pipefitting book.

By RockerB (**)

Date 05-24-2009 17:18

Thanks for the info. Ill check my local welding supply for one before ordering. Its quicker that way. Otherwise I'll just order that one. Anything beats running thru the trig formula!!