B31.1 Excessing flange ratings
B31.1 Excessing flange ratings
(OP)
Hi Boys,
I read already several threads in here, but didn't find an answer for following issue:
Is there any possibility to excess the pressure/temperature ratings of B16.5 flanges under B31.1? Coming from EN 1591 Standards there is a way to calculate B16.5 flanges with higher values than mentioned.
Background is that several valve suppliers are giving me excess rated flanges: Valve flange is #600 but according 31.1 I shall use #900.
Many Thanks!
I read already several threads in here, but didn't find an answer for following issue:
Is there any possibility to excess the pressure/temperature ratings of B16.5 flanges under B31.1? Coming from EN 1591 Standards there is a way to calculate B16.5 flanges with higher values than mentioned.
Background is that several valve suppliers are giving me excess rated flanges: Valve flange is #600 but according 31.1 I shall use #900.
Many Thanks!





RE: B31.1 Excessing flange ratings
What pressures are involved here?
What section of 31.1 are you using to calculate #900
Is this a materials / temperature de-rating issue?
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: B31.1 Excessing flange ratings
RE: B31.1 Excessing flange ratings
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: B31.1 Excessing flange ratings
Sorry, but you're stuck, they way the rules are currently written.
If you want to change the rules, start attending the B31 Code Committee Meetings.
RE: B31.1 Excessing flange ratings
RE: B31.1 Excessing flange ratings
RE: B31.1 Excessing flange ratings
RE: B31.1 Excessing flange ratings
What I am telling you is that there is no route to use EN1591 calculations to DEMONSTRATE a temperature/pressure higher than the B16.5 ratings available in ASME B31.
You simply can't get there from where you are.
RE: B31.1 Excessing flange ratings
100 bar at 60C and 100 bar at 110C is within the ratings for pressure for class 1.2 materials, which should be easily available, but may cost a fraction more than 1.1.
Or use materials listed in ANSI / MSS SP44. No de-rating below 121C
It's all about the material which you haven't specified.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: B31.1 Excessing flange ratings
Another approach maybe. Reading through B31.1 104.7 Other Pressure-Containing Components and take 104.7.2 consideration would allow also flanges according EN 1759 with the calculation from EN 1591.
The interesting thing is that the customer spec also requiring the EN 1759 for flanges.
RE: B31.1 Excessing flange ratings