High temperature (650 Deg F) stud material for 8 inch, Class 300 steam flange

[racookpe1978]

Reference Thread: thread292-404005 (Now closed)

We are replacing the B31.1 saturated steam piping from a competitor's existing turbine casting.

7x flanged pipe connections from the turbine are built up from the turbine with "standard" ASME pipe flanges welded to pipe stubs welded to the casing. Our new pipe flanges match those 7x turbine flange dimensions and bolt circle diameters, thickness, etc perfectly. No problems.

Design conditions at the last flange are 650 deg F at 320 psig.
This turbine flange is cast integrally with the turbine upper casing. Its machined surfaces and tapped holes match the dimensions for the expected mating 8 inch Class 300 pipe flange although the flange OD and cast thickness differ. The 12x Studs will be 7/8 diameter x 5-1/4 long.

However, I cannot find a clear requirement for the stud material: Steam Temperature is 650 F, but I do not want stud stretch over time by assuming the wrong material.

 

[SnTMan]

Be hard to go wrong w/ B7 I'd think...

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[BJI]

If you wanted to be on the safe side you could go to B16.

 

[KoachCSR]

For 650 deg F, I agree that A193 B7 is appropriate. As BJI states, A193 B16 can be used, but will really be overkill.

B7 should be good for up to about 750 deg F service temperature applications. B16 is good for up to around 1,000 deg F.

 

[racookpe1978]

My thanks to all. We've ordered B7 material.