Hello.

How can the MAWP of a pressure vessel be limited/restricted by non pressure parts like saddles/lifting lugs.

Thanks a lot. I really appreciate it.

Sharjeel

The saddles impose local stresses in the shell during operation. Similarly, other structural attachments such as pipe support clips, platform support clips, etc, will also impose local stresses during operation. The calculated local stresses (calculated by Zick analysis for saddle, or WRC-107, EN 13445, FEA for other attachments, etc) must be within the corresponding allowable stress.

If the local stress produced at the saddle (or some other structural attachment) equals the corresponding allowable stress at some given pressure, while the same pressure does not result in similar stress state (ie: calculated stress = allowable stress) for any other components...shell, heads, etc, then, by definition, the given pressure is the MAWP of the pressure chamber.

Most often it is likely simplest to find the MAWP of the shell and heads, then design the saddle and nozzles to meet this pressure.

Thanks a lot.