MAWP and design pressure 1

[Melimelo]

I am reading right now the API 520 that I found very interesting...
Well, in this document, they specify a difference between the MAWP and the design pressure;
It is said that "MAWP is normally greater than the design pressure".
Is it the same rule everywhere I go or could it change from company to another one?
Thanks!
Méli )

 

[zdas04]

MAWP is "Maximum Allowable Working Pressure". Normal operating pressure cannot exceed this number. Design pressure is the "expected" working pressure and is always less than MAWP.

For example, you have a gathering system that you expect will have 350 psig at the farthest well and you are designing your compression inlet for 100 psig--most people would use ANSI 300 flanges and valves and "standard" pipe (e.g., Sched 40 for 6-inch) for this system (MAWP around 600 psig) to make sure that normal transients don't approach PSV set points on vessels.

David

 

[CJKruger]

Melimelo,

MAWP must always be greater than or equal to required design pressure.

Some companies prefer to make them the same (by varying corrosion allowance on vessels), while some don't.

 

[Samiran]

Check this faq135-133

 

[RotaryG]

I would like to interpret that the Design Pressure is the maximum pressure to which the System is designed to and safety features are incorporated to ensure that the operating pressure does not exceed the Design Pressure. The MAWP relates just to the peressure vessel or a compressor casing as the case may be.

Regards

Evolution rather than Revolution!

 

[djack77494]

I like to think "Design Pressure = Minimum needed to meet Process Requirement"
"MAWP = Actual Vessel Mechanical Design"

Let us hope that the actual mechanical design always meets the minimum requirement.

 

[786392]

I consider from the very meaning of word(s)
MAWP=
Maximum(Maximum) Allowable Working (Withholding strength capablity) Pressure


Best Regards
Qalander(Chem)