Hi all,

We are a pressure vessel manufacturing company, I want to standardize the nozzle loads for our steam drums for a range of pressure and temperatures.
Can you guys please tell me what is the procedure to standarize the nozzle allowable loads for the nozzles of a vessel so that when piping team designs piping they can use those allowable loads and do the piping at their end.

Dear friend

I appreciate the post and your intention is correct and very difficult.

Please refer to WRC 107/ 297 appendices. Even if you limit the allowable stresses in piping at the nozzle end to 25%, the nozzles may fail. In my personal experience, I have come across cases where piping engineer has limited it to 10% of code allowable, still nozzle was found to be failing on FEA.

I agree that a thumb rule value can be taken for the piping analysis but parallely nozzle shall be checked which may demand revising piping routing or supports.

It is a highly subjective number in my opinion and may be different case to case.

_________________
R.SRINIVASAN
Sr. VICE PRESIDENT
Head, Design and Engineering
PED,ISGEC,
YAMUNANAGAR
HARYANA -135001
INDIA