Finding ASME B16.5 Blind Flange Bolt Load
Having a difficult time figuring out the Bolt Load (W) for your modified ASME B16.5 blind flange? Check the flange it is attached to!
Oftentimes ASME B16.5 blind flanges used as reducers include pipes larger than allowed in B16.5 without a reinforcement calculation. I have found that the additional bolted cover calculation trips up some designers as they were expecting the ASME B16.5 blind flange to be exempt. The most common reason people reach out to me is for help finding the Bolt Load (W) needed in the bolted cover required thickness calculation.
Please remember that mating pairs share the Bolt Load (W). This means that finding the Bolt Load (W) needed for the bolted cover required thickness calculation may be as simple as grabbing it from the flange it is attached to.
ASME PCC-1 Appendix O
ASME PCC-1 Appendix O has a lot of stress values to look up (or calculate) and using “defaults” isn’t going to help you solve real world problems. Over the next few weeks I’ll be going over where to get some of the stress values you will need in order to properly determine bolt torque values using ASME PCC-1 Appendix O.
Maximum Permissible Bolt Stress, Sbmax
Minimum Permissible Bolt Stress, Sbmin
Target Assembly Gasket Stress, SgT
Maximum Permissible Gasket Stress, Sgmax
Minimum Operating Gasket Stress, Sgmin-O
Minimum Seating Gasket Stress, Sgmin-S
Assembly Bolt Stress, Sbsel
Wait, just seven stress values? That seems way too easy! It is! But let’s start here and save the Maximum Permissible Bolt Stress for the Flange, Sfmax determination calculation using WRC 538 for after your exam.