Dear All Members,

I have one stainless steel vessel with 14.5 bar internal design pressure, 50 degree Celcius, use SA 182 Gr. F316L 150# Rating(Material Group 2.3) According to code UG-99b[34], hydrotest pressure =1.3 x design pressure =18.85bar but as per table 2-2.3 ASME B16.5-2003, the max pressure of these flange is 15.3bar. That will effect on Flange rating or not?

Could anyone clarify to me?

thank you

_________________
Faizol
(PV-elite User)

Please refer ASME B 16.5 section 2.6; System Hydrostatic Testing

Flanged joints and flanged fittings may be subjected to system hydrostatic tests at a pressure of 1.5 times the 38°C(100°F) rating grounded off to the next higher 1bar(25psi) increment.

Regards

The flange operating pressure is listed in the rating table, the hydrotest pressure may be higher. There will be no problem for the flange.

DK

Let me add my 2 cents from experience.
B16.5 (or RF in general)- I fully agree.
Problems begin with full-face contact metat-to metal flanges (appendix Y-style) and their bolts. When you calculate bolt stresses during hydrotest, you quickly find out, that they rise tremendously due to the flange shape (lever!). As a rule of thumb, full face flanges need to have bolts replaced after a hydrotest. And, of course, do not overtighten them before the test, they may break!
Konrad

_________________
Konrad Anikiel