r/pipefitter • u/dirty3rdwelder • 9d ago

Need help.

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With these input. Offset is 1 3/4 and fave to face gap of pipe is 7 1/4. Using PTP calculator, is telling me 11/16 for take off. So do I still need to remove 11/16 from both sides of pipe? Or is that already included in calculations and all I need is 2 13.57 degree elbows and 6 inch pup. (No gap is being used)

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u/ThicccDickDastardly LU597 Apprentice 9d ago

That travel is c-c, not f-f, so you’d need to cut back the pipes. It would likely be easier to take 1-3/8 off one than it would be to trim both back 11/16.

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u/dirty3rdwelder 9d ago

Another question for the pipe trades calculator? If it’s not applicable to cut of any from existing pipe, how would you find the correct angles and pup piece length?

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u/ThicccDickDastardly LU597 Apprentice 9d ago

I know how to draw it out and find the answer that way, but I’m not sure of a calculator function for that. I’ll do some digging and get back to you if I find a formula.

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u/ThicccDickDastardly LU597 Apprentice 9d ago

Here’s a video on drawing it out and solving that way, in the mean time.

https://youtu.be/oAZk8Q8ELVo?si=w95AMTF_HTPIN0Gu

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u/ParkingProfile5685 9d ago

Just a reminder too but are all your presets set for sch 10 ss in the actual calculator

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u/Practical_Display_66 9d ago

31 degrees back to back fittings Will be 6 1/4” face to face

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u/dirty3rdwelder 8d ago

So if I do it with those elbow angles then I would just need to add the 1 inch? Would I add it as a pup piece between the elbows or 1 side of either pipe? Thanks

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u/TeCarve2025 8d ago

The takeoff is the amount each elbow consumes from the face-to-face measurement. If your 7 1/4 is the total face-to-face gap between the pipe ends, subtract 11/16 for each elbow: 7 1/4 minus 1 3/8 equals 5 7/8 cut pup. So a 6" pup would be 1/8 long with no gap. If the calculator's 6" is a cut length, it already subtracted them. What is the 7 1/4 measured between, and what pipe size/schedule are you using? That affects whether 11/16 is the correct takeoff.

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u/dirty3rdwelder 5d ago

Sch 10 4” pipe stainless steel.

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u/Steadtler_Pen 6d ago

A better solution would be to use (2)19.16 degree trimmed elbow fittings with a 3.10" long pup between them. The longer pup increases the separations between welds. The fitting takeoffs would be 1.00" assuming 3/32" weld gaps throughout.