SAE Gr 8 bolting in Low Temperatures

[JohnKTexas]

I have 4000 bronze bodied three piece ball valves with Grade 8 bolting. The manufacturer has rated the valves to -20 F service conditions.

I am using the valves at 1/3rd the rated valve pressure and want to know how I can justify a lower working temperature based on the lower working pressure I am using the valves in.

I do not want to change out all 4000 valves with SS bolting if I can help it.

Can someone show me a method to rate Grade 8 bolts to temperatures of -30 F. The bolt sizes wre 5/16" to 1/2"

 

[iainuts]

Hi John. I'd suggest reposting in the Valve Engineering forum here:

http://www.eng-tips.com/threadminder.cfm?pid=408