AutoPIPE - Head Thickness Calculations as per ASME Section VIII Div. 1

Code References: AutoPIPE Vessel performs head thickness calculations in accordance with ASME Section VIII Division 1, primarily referencing:

UG-32 (Design of Pressure Vessel Heads)
Mandatory Appendix 1, 1-4

The selection of the governing formula depends on the ratio: (ts/L).

Where:

- ts = shell (or head) thickness
- = characteristic length (e.g., diameter)

Conditions:

1. When Appendix 1-4(d) is applicable.
2. When ts/L<0.002: In addition to UG-32 requirements, the rules of Mandatory Appendix1, 1-4(f) must also be satisfied.

Report : Covers both requirements: Appendix 1-4 (d) & (f) as applicable for torispherical head

Nozzle opening calculation:

For the nozzle opening calculation UG-37 (a), the primary reference is UG-32, which further refers to Appendix 1, 1-4(f), see:

Accordingly, the reported value of (tr) in opening calculations represents the maximum of all minimum required thicknesses calculated as per UG-32 and its associated references.

In this case, minimum required thickness (tr) in nozzle opening calculation is the smallest thickness, obtained by iteration, that satisfies condition 1-4(f)(1)(-i).

Why Head minimum thickness calculation in Summary of Thicknesses is different:

This is due to the application of paragraph 1-4(f) in Operating condition.
It is the smallest thickness, obtained by iteration, that satisfies condition 1-4(f)(1)(-i).

The minimum head thickness is the largest of the minimum required thicknesses, calculated according to all code requirements. In the case of ASME, there are two values to calculate: one obtained by direct calculation for Appendix 1-4(d), and another by iterative calculation for Section 1-4(f).

To this must be added the value of the straight flange (not relevant here).

These 3 calculations are clearly mentioned in the report...