ASME B31.3 PIPE WALL THICKNESS FOR A THREADED PIPE

[vi_shj]

Dears,

I am using ASME B31.3 appendix K for a high pressure 1" line. I used 12.5% for mill allowance, 0.236 as corrosion allowance as per project specification and 2 mm thread allowance. But in NPT type threads are inclined and OD will be lesser than the standard OD (1.32
"). so how should i calculate this. Please help.

 

[LittleInch]

Why don't you put down your calculation.

Note that pipe is supplied in standard OD, but variable thickness. What you usually work out is thickness, not OD.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[EdStainless]

You will get 1.050", 1.315", 1.600" OD depending on what you order.
Picking the correct schedule for wall thickness is your task.
I believe that 1 NPT sch160 is 1.315" OD x 0.250" nominal wall.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy

 

[vi_shj]

DearS,

Please refer attached calculation sheet for 1" NPS nipolet which is welded in 6" NPS pipe. I calculated the wall thickness as per B31.3 & B31.8. For both wall thickness calculation I need to provide actual OD of the pipe.

My concern is Nipolet is with male NPT thread and at the tip of nipolet 1.315" will not be there due to its taper and around 1.213" will be available. So should i consider less OD or to add high thread depth allowance to mitigate the issue