Specifies whether to evaluate the flanges using the Kellogg Equivalent Pressure Method or the ASME B&PVC Section III Subsection NC-3658.3 method.
Peq
Evaluates the flanges using the Kellogg Equivalent Pressure Method.
Peq = 16M/(p)G3 + 4F/(p)G2 + PD £ Pressure Rating
Where:
Peq = equivalent pressure (for checking against flange rating)
M = bending moment on flange
G = diameter of effective gasket reaction
F = axial force on flange
PD = design pressure
NC-3658.3
Evaluates the flanges using the ASME B&PVC Section III Subsection NC-3658.3 equation (12) method. The software rearranges the equation so that the factored moment is less than the limit:
(36,000/3125) * Mfs / (C * Ab) < Min(Sy, 36000 psi) in U.S. customary units
(250/21.7) * Mfs / (C * Ab) < Min(Sy, 250 MPa) in SI units
Where:
Mfs = Bending or torsional moment (whichever is greater) acting on the flange
Sy = Yield strength of flange material at design temperature
C = Bolt circle diameter
Ab = Total cross-sectional area of bolts
For the ASME B&PVC Section III Subsection NC-3658.3 equation (13) method for dynamic events (Mfd), double the limit.