Design for MAWP or MAP

[susanbhj]

Dear friends,
While designing nozzle for "design for MAWP or MAP", I noticed that while checking for MAWP case for nozzles, compress is adding Liquid static head on flange.

Guys, do you think it is necessary to add liquid static head? In my opinion it is not required.

What do you think, guys? Share your opinion.

Regards,
Susan

 

[vesselfab]

the pressure, whether map or mawp is at the top of vessel. the code requires that you design for all known loads. static head is a load on nozzles, especially those low in a liquid vessel.

 

[NTME76249]

We add a static liquid load to all vessels just to be safe, it can really make a difference on large OD Vessels. I would recommend it.

Michael McMillan

http://cadtechie.blogspot.com/

 

[AK23Static]

Software approach is correct, consider the situation of Column design where liquid head can make quite a big difference for the nozzle located in the bottom section.

cheers
AK
Beginning of every success is desire

 

[vesselkid]

susanbhj, MAWP for a vessel is measured at the top of the vessel (i.e. without hydro-static head); however, for each competent, MAWP shall be computed based on min. thickness and corroded diameter; Hydrostatic head at a point in a vessel must be added to the pressure used (normally vessel MAWP) when calculating the required thickness of the vessel component at that elevation; however, You must subtract hydrostatic head pressure when determining the MAWP of a vessel. If given a vessel of multiple parts and the MAWP for each of the parts, the MAWP of the entire vessel is determined by subtracting the hydrostatic head pressure at the bottom of each part to find the part which limits the MAWP of the vessel.