Flange Rating

[Mechh007]

How can we choose flange rating?
one way is referring B16.5. Is there anyother calculation to select flange rating?

 

[austsa]

Pressure rating can also be calculated. However, my understanding is that you'll end up with more conservative (lower pressure) than B16.5.

 

[Mechh007]

Thanks austsa. So you are saying that it would be better to refer B16.5 rather than doing calculation. am i right?

 

[zdas04]

This is a case where using the widely published maximum pressure from 16.5 reduces the number of times you have to produce your calculations to justify using a different number. If I see an ANSI 150 Class flange rated at 50 bar, I am going to want to see the justification and I am most likely going to be more than a bit skeptical (although I had a fab shop misread a set of plans once and I walked into the shop to see the end of a successful 62 bar test that included 3 pairs of ANSI 150 Class flanges that held up just fine, we cut them off and redid the test with the ANSI 300 Class flanges I specified). There is no benefit to ignoring 16.5.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

 

[austsa]

MH, yes that's my understanding. Sometimes (eg flange size/rating falls outside B16.5 and B16.47 - eg in pressure vessels), then calculation is the only option.

 

[Mechh007]

do you know the calculation? if you know please share here

 

[C2it]

Flange calculations may be made in accordance with:

ASME VIII Div 1 App 2

ASME VIII Div 2 Section 4.16

PD 5500 Section 3.8

EN13445 Pt. 3 and App G.

EN-1591.

And others.