Dear members,

ASME B16.5 covers flanges's strength until 1.5 times of highest pressure of its pressure class and material category, then round up to nearest 1 bar.

For example, SA105 (mat. group 1.1)flange with pressure class 150, highest working pressure is 19.6 bar. Max. HT pressure it can stand will be 1.5 x 19.6 = 29.4 or 30 bar after rounding up.

Occasionally, special customer requirement will set the hydrotest pressure higher than UG99c requirement. Say if there is a case HT required at 31 bar, shall PVElite prompt warning/failure the flange pressure class is in-sufficient to be tested at 31 bar?

Quite often PVElite warns about MAWP/MAP governed by flange before the hydrotest pressure applied > limit in B16.5 above. Design engineer might overlook if PVElite does not prompt or does not check manually.

Opinions are welcome.

S K Tan

As per B16.5,
Flanged joints and flanged fittings may be subjected to system hydrostatic tests at a pressure of 1.5 times the 38ºC (100ºF) rating rounded off to the next higher 1 bar (25 psi) increment.

Testing at any higher pressure is the responsibility of the user, taking into account the requirements of the applicable code or regulation.