hello, my dear friends,
waiting for your advice!
one expansion bellow manufacture is manufacturing a few "U" type expansion bellows.
based on the vessel situation, the bellow thickness will be definitely beyond the thickness limit 5mm according to Appendix 26,so how to deal with such situation, what calculation basis shall the manufacturer rely on? thanks for your kind help!

Fred,

as an Inspector, you can not accept a violation of the limits in the Code.

But you can point your finger at 26.4.1(e)&(f).
Try to avoid to make decisions for the manufacturer. It is his responsibility to manufacture the bellows, not your.
Your role is to make sure he meets Code. I suggest you contact your AIS if you are in doubt.

DK

Thanks, Dr. Koelbl!