Pressure Vessel Head

When designing a pressure vessel head with pressure to the concave side, UG-32 of Section VIII, Div.1 is applicable. If an ellipsoidal, or torispherical, head is to be attached to the vessel and the minimum head thickness calculations, per UG-32, are found to have ts/L<0.002, we are directed to the Section VIII, Div, 1 rules of Mandatory Appendix 1, Part 1-4. In Part 1-4, K is a factor to be used in the formula (1) calculations for the minimum head thickness required. The values of Factor K are predicated upon D/2h, and are found in Table 1-4.1 of Mandatory Appendix 1.