MAOP and Design pressure difference

[ElvisWilliams]

Good morning all.
Please, I need understanding on the difference between MAOP and Design pressure.
1. I understood that MAOP is a limit set, usually by a gornment body, which applies to compressed gas pressure vessels, how can I get this set limit in order to design gas pipeline, PMS pipeline?

2. I understood the design pressure is 10% - 25% higher than MAOP, how come then that is design has Opreting pressure (kg/cm2g) and the design pressure is 10.55 (kg/cm2g)?

 

[LittleInch]

Vessels work to a different system than pipelines.

They have MAWP, max allowable working pressure which can be higher than the design pressure. A bit odd to me but that's how it is.

MAOP appears in some design codes but not all and is set by the designer usually. In reality MOP or MAOP has to be a bit lower than design to allow for variations and margins for alarms and trips. Around 10% is common but it's up to you.

Just note that B31.8 has no overpressure allowance unlike say B31.4 and other codes.

I think you've missed some data out of your last paragraph?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[LittleInch]

Also try this past and scroll to the end.

https://www.eng-tips.com/viewthread.cfm?qid=229469

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.