ASME B31.4-2019 Chapter II Design Part 2 Sections 402.1 to 402.4

In Chapter II we continue to describe the concepts of B31.4 procedures for flexibility analysis. The standard has specific requirements for mechanical properties allowing less latitude foe the designer. The hoop stress equation is introduced in terms of flexibility for positive and negative pressures. An example calculation is provided.
The section ends with an explanation of the traditional methods for calculating the stress intensity factors for B31.4.
Mechanical properties
Internal Pressure - Hoop Stress
External Pressure - Hoop Stress
Stress Intensification Factors

[@rodneyramcharitar2300]

Nope. Do a worked example. Always adds max value. But your info and explanation is spot on and really appreciated.

[@dgreen1944]

why D/d is 57? Not sure where the 16 is coming from?

[@rodneyramcharitar2300]

At least imo