Flange connection vs. butt weld on critical steam line.

[T5580]

A steam line design condition at T=1050 F, P=1340 psig. Is it practical to have stop valve a flange connection instead of butt weld? What is a major concern if the flange connection being used from the stress point of view? Your input is appreciated.
Regards

 

[DSB123]

T5580,
It's very dangerous to have flanged joints on steam at the pressure and temperature you mention. Any leak at the flanged joint would not be visible and personnel could be fatally injured by an escape. We never use flanged joints in such a steam line. Also the bolts would relax giving more problems with leakage.

 

[abeltio]

Fully agree with DSB123, there is another practical consideration... welded joints can be 100% x-rayed and certified ok. flanged joints will require a pressure test that most likely would be prohibitive in terms of weight of water to perform the test.

saludos.
a.