Dear Mr. Richard Ay,

Thank you for your answer.

Really I appreciate it. For me is the first sign I'm spending my time with some profit.

Well, in this case I have some suggestions for the future flange calculator.

1. The Taylor-Forge/ ASME philosophy is focused on the conservative assumption that the pressure is discharging only the gasket.
The stress on gasket evolves from Y value at p=0 to the m*p_max value at p_max. The gasket load at p_max is HG=2 * b * Pi * G * m * P_max and is less than the gasket load at p=0 i.e. HG=W0.

For this reason HG=2 * b * Pi * G * m * P is a tricky equation when trying to describe the gasket load.
Instead HG=W0-P*Pi/4*G^2 is the correct equation ("correct" in the limits of the assumption made). The equation is more complicated when a bending moment is acting, because in this case HG is variable along the gasket circumference.

I understand the flange calculator is a structural model based on correlations on how really the bolts and the gasket are interacting.
For this reason I’m sure that you can calculate- numerically- the HG load given by the coincident p_operation, M and F, by following this model instead to consider an equation to describe it. In this assumption, the "Taylor Forge" index I’ve proposed makes sense, because in operation we need to be sure that

HG_operation > 2 * b * Pi * G * m * P_max.

This index would be:

Index= HG_operation/ (2 * b * Pi * G * m * P_max)=
=(Gasket stress in operation)/ (m * P_max)>1

No code is asking this index because no code is checking the operational conditions.

2. About the contribution of the axial force in Peq.

It’s true that considering negative values for forces (compression) it’s not conservative for the design of the flange. This is specifically asked in ASME VIII Div.2.

But a compression force might be a real condition for operational conditions applied on a piping flange.

The equivalent pressure concept is conservative enough because the assumption made, it’s no need to help this formula by considering axial force as tensile forces if we really have a compressive force.
For this reason, really I think in the next version, the calculator would accept negative (compression) forces.

Thank you very much for your information...and of course for your calm endurance considering my long posts, getting bored everybody.

My best regards.