3" A193 B7M Allowable Stress 1

[bmoorthy]

Hello All

Where can i get the allowable stress for A 193 B7M (3" dia). ASME Sec II D gives allowable stress only upto 2.5" diameter.
The application: Sub Sea Flange (Sub Sea Fastener)

 

[metengr]

You won't use ASME Section II Part D. But you can use ASME B31.3, look in Appendix A, Table A-2. For ASTM A 193 Grade B7M bolting, the design stress value is good to 4", actually 4" and less in diameter.

For your sub sea flange (design temp from min to 100 deg F), the design stress is 20 Ksi.

 

[bmoorthy]

Thank you Mmetengr

Is it Ok to use B 31.3 Stress values if the design is B 31.8.

Does 31.8 permit the use of 31.3 values and formulae?

 

[metengr]

I glanced briefly thru B31.8, which is “Gas Transmission and Distribution Piping Systems”. You need to review it carefully, although there are references to other B31 Pressure Piping codes. Unless there is a specific exception stated in B31.8, I see no reason why one could not use accepted stress values for materials stated in other B31 Pressure Piping Codes provided the proper application is considered.