Stressed during hydrotesting for flanges

[VIJAYA1234]

Hi,
I am trying to do Engineering design calculations for a flange which needs to be hydrotested. I checked ASME section VIII div 1 and did not find anywhere that gives me the stresses and acceptable criteria for the stresses during hydrotesting.
I have the Appendix P for designing a flange but how about the stresses during hydrotesting and its acceptance criteria??
Any help is greatly appreciated
Thanks
Vijaya

 

[SnTMan]

VIJAYA1234, there are no explicit limits in Sec VIII, Div 1 for stresses at hydro. However, per UG-99 if "the vessel is subjected to visible permanent distortion, the Inspector shall reserve the right to reject the vessel." So that kind of sets an upper bound.

A fairly common industry practice is to limit stresses (presuambly calculated by Code rules) at hydro to 90% of yield at the test temperature, normally ambient.

If you flange is designed to Apx 2, and your hydro is even as high as 1.5 X design pressure you shouldn't have anything to worry about.

Regards,

Mike

 

[LSThill]

VIJAYA1234 (Mechanical) and Mike

Also, Sec VIII, Div 2, Apx 3,

L S THILL