Permissible Variation in Diameter according to ASME VIII Div.1 3

[patchlam]

Dear all Engineers,

My pressure vessel is fabricated of 1.5" SCH 40 SA 106 B pipes and under internal pressure. However, the pipe is not straight, but is bent into a helical shape with the minimum radius of 17D. May I know what is the ovality tolerance that I should follow during the pipe bending?

Thanks for your time.

 

[pdiculous963]

Take a look at UG-80 of ASME Sec. VIII Div. 1. The difference between the maximum inside and outside diameter shall not exceed 1% for internal pressure. There is a slight increase in this tolerance at nozzle openings.

 

[every_name_is_taken]

To add to what pd has to say: you should specifically look at UG-80 (C). Since you have made this out of pipe, you need to comply to the specification of the pipe. In your case ASTM A106. For 1.5" pipe the permissible variations in OD are ±1/64".

 

[r6155]

@ every name is taken:
Tolerance of diameter is not the same that the tolerance of out of roundness.

Regards
r6155

 

[r6155]

See
PIPE FABRICATION INSTITUTE
PFI Standard ES-24
Pipe Bending Methods,Tolerances,Process and Material Requirements
Prepared by Engineering Committee

https://es.scribd.com/doc/235585537/PFI-ES-24-Pipe-Bending.

Regards
r6155