The minimum required thickness at the thinnest
point after forming18 of ellipsoidal, torispherical, hemispherical,
conical, and toriconical heads under pressure on
the concave side (plus heads) shall be computed by the
appropriate formulas in this paragraph,19 except as permitted
by Appendix 32. Heads with bolting flanges shall meet
the requirements of UG-35.1. In addition, provision shall
be made for any of the loadings listed in UG-22. The
provided thickness of the heads shall also meet the requirements
of UG-16, except as permitted in Appendix 32