B31.3 has adopted certain wants and desires out of the PED in order to obtain ISO-ization.... I found it to be a rather lengthy tome but it had a few gems in it....

Wonder if Zahid has his problem taken care of?

Another thing that could be a factor in a sustained overstress is very high pressure... the long axis pressure stresses are usually a small percentage but I have seen them drive the design towards added supports.....