thickness to be used in a raised face flange 1

[frfouqa]

Hi,
I 'm looking for an information.
I try to compute a blind flange 8" 300lbs (from the B16.5) as a flat head drilled with a 40 mm hole diameter.
The american standard say that the minimum thickness is tf=39.7 mm and the raised facing is 2mm.
To know if my blind flange is adequate under pressure, can i consider the thickness of the flange is 39.7 mm or 41.7 mm to do calculation ?
And gnerally speaking, can we consider the thickness of the raised face for calculation?
Thank you for your answer.

 

[SnTMan]

frfouqa, compute it how?

See ASME B16.5, Para 6.4 for facings dimensions.

See ASME Sec VIII, Div 1, Apx 2, Fig 2-2, General Note (b) for this Code.

Regards,

Mike

 

[doct9960]

frfouqa,

You don't need to perform pressure calculations if the hole is just 40mm.

The B16.5 pressure-temperature of your 8" Class 300 blind flange is still valid if the corroded I.D. of the hole does not exceed 88.9mm. Check Table 6 of ASME B16.5.

 

[frfouqa]

Hello,

Thanks for you answer.
I find ine the general note of the ASME (as SnTMan has suggested to me) that if the facing thickness is greater than 1.5 mm, i Can't take it.
Regards,