MAY IKNOW THE DERIVATION: TRUNNION LOAD CHECK CALCULATION
HOW KELLOG DERIVED THE FORMULA FOR BENDING STRESS IN A CYLINDRICAL SHELL AS :

[1.17*f (R^0.5)]/(t^1.5) = bending stress

f- load induced by trunnion attachement
t- CORRODED WALL THICKNESS
R- outside radius of pipe

Regards,
Piping Stress Graduate Engineer

Try reading Kellogg and maybe Roark.

Hello Moverz...

Thanks for your reply.

i already tried Kellog. He gave only direct formula.

may i will try with roark as you said.