Instructs the software to use the simplified form of the longitudinal stress term when computing sustained stresses. Some codes permit this simplified form with thin-walled pipe thicknesses.
This option is used most often when you are comparing CAESAR II results to older pipe stress software results. In most cases, you should use the more comprehensive default calculation.
The software ignores Use PD/4t for the offshore codes B31.4 Chapter IX, B31.8 Chapter VIII, Canadian Z662 Chapter 11, and Det Norske Veritas
(DNV).