API valve/bonnet connection

[yld]

For API vavle, do we have to use studs and nuts to connect the bonnet (for actuator) to the valve? I am think about using socket head capscrews to connect them, will this violet some industry standards? I did not find anything metion about using bolts in API 6A, but in ASME B16.5, there are certain limitations to use bolts, ie. have to be hex head etc.

Thanks a lot.

 

[EagleKnee]

I have seen the hex head bolts used on the smaller 2 1/16" 3K valves.However, I believe there are specs spelled out in API 6A as to what is acceptable for PSL1 to PSL4 valves.

hope that helped.