Q. Bolt Stress to Seat the Gasket?

The required bolt stress to seat the gasket can be calculated, using the recommended gasket seating stress provided by the manufacturer in accordance with Equation.

S_B = A_s * S_B/A_b

Where:

S_B = bolt stress at ambient temperature (psi)

A_b = total cross-section root area of bolts (in²)

S_g  = actual stress at gasket bearing surface (psi)

A_g = gasket area (in²)

A_g = 0.785 * [(d_o - 0.125)² -d_i²]            for standard flanges    

A_g = 0.785 * [d_o² -d_i²] + (Rib Area)      for equipment flanges

d_o = outside gasket diameter (in)

d_j = inside gasket diameter (in)