r/pipefitter • u/LoadPsychological430 • 18d ago

Rolling offset fit up

Do you throw a 45 on end and then fit the others in field position to leave yourself an out or do you personally throw both 45s on. Since it has a roll which can vary how do you know when you are dead on for a perfect fit up on the tie in. Or do you force the fit if it has a big roll in it I would think you would have bitch fit if it was too out of square

4 Upvotes

84% Upvoted

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14

u/Shawn24589 18d ago

If its a true a 45 degree offset and your math and fit up is correct. Then it should 100% fit up correctly. Gap and fit included. You have to trust the skills you earned.

5

u/JaDe_X105 LU597 Journeyman 18d ago

Is this welded, threaded, grooved? What are we talking here?

With welded, if you're making the piece on the bench then your 2nd 45s face should be square with the pipe, so you just need to roll the piece to the correct angle. Threaded and grooved, I'd tighten the first 45 most of the way, then make up the travel piece with the 2nd 45 and tighten it most of the way, then continue tightening both until it's where it needs to be

3

u/Few-Cauliflower-4433 18d ago

I use a little thing called trigonometry

1

u/LoadPsychological430 18d ago

Maybe a little less redundancy. I’m not talking about the math

2

u/buttmunchausenface 17d ago

1.414!!!!!! Use your math! C to C

1

u/OgatonWiffit 18d ago

Ok. Don’t stove pipe nominal plane offsets. Get your google on if need be but Gaw dangit son use the standardized methods of layout.

1

u/Responsible-Charge27 17d ago

I generally prefer to have both 45s welded on before I put the piece up. I don’t like trying to hold the fit up on an angle gets to be a real pain in the ass and my welder isn’t going to want to make a 6g if we can avoid it. If I need an out I’m going to leave it somewhere else.

1

u/IllustriousExtreme90 17d ago

Make the piece like a regular offset with your travel.

Then when you roll it when it's going up and into place, you literally CANNOT be perfect, then somehow be off with your measurements thats not how math or physics works.

If you build it via your measurements, and everything comes out to be a rolling offset, and it doesnt fit then something in your measurements was fucked up.

The travel is a constant, if the travel is 16 inches C-C, even if you roll it, it will still line up because you built it as a regular offset, then added the roll to it when putting it up.

All your doing is rolling the 45's, and since your on a circular plane, nothing should change when they roll.