Sfmax Made Easy

We need to have a heart-to-heart talk about the Maximum Permissible Bolt Stress Prior to Flange Damage, Sfmax. 

I see a lot of really high “default” values to make sure it never governs the Selected Assembly Bolt Stress, Sbsel inside of the ASME PCC-1 Appendix O calculation. This is an unconservative approach because it ignores the actual flange stresses that can be attributed to leaky gaskets. 

I prefer that the Target Assembly Gasket Stress, SgT governs the Selected Assembly Bolt Stress, Sbsel instead of Sfmax inside of the ASME PCC-1 Appendix O calculation. In other words, I do not want the flange to yield before the gasket seals properly. That is exactly why I like to make sure I calculate an accurate Maximum Permissible Bolt Stress Prior to Flange Damage, Sfmax value by iterating on all seven flange stress combinations. 

The Maximum Permissible Bolt Stress before Flange Damage, Sfmax governs the bolt stress applied to the bolted flange joint assembly for many Class 150 and Class 300 standard ASME B16.5/16.47 flanges. 𝐏𝐥𝐞𝐚𝐬𝐞 𝐝𝐨 𝐧𝐨𝐭 𝐨𝐯𝐞𝐫𝐥𝐨𝐨𝐤 𝐭𝐡𝐞 𝐒𝐟𝐦𝐚𝐱 𝐜𝐚𝐥𝐜𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐟𝐨𝐫 𝐀𝐒𝐌𝐄 𝐬𝐭𝐚𝐧𝐝𝐚𝐫𝐝 𝐟𝐥𝐚𝐧𝐠𝐞𝐬.