MAWP

[ysc295]

Dear sir,

Whenever we do Pressure Vessel calculation either Div.1 or Div.2, MAWP is calculated for shell, head and nozzles only. Why MAWP calculation is not done for internal tray supports which are also having lot of internal pressure falling on it. Please advise or give your opinion.

Thank you,

Regards,
Sameer

 

[JohnGP]

Internal tray supports are not part of the pressure boundary, so do not need a MAWP calculation performed. They do need to be designed to support loadings applied to the trays, but pressure forces should balance out.

 

[PVDEngg]

Sameer,

w.r.t VIII.1: Pressure calculations as per say UG-27, UG-28 or UG-32, UG-33 or UG-34 are performed for 'pressure component', by meaning component having different pressures on two surfaces of it.

Internal support rings and trays, generally are process components with same pressure on either sides, so there happens no pressure difference. Hence, no MAWP calculations.

 

[SnTMan]

If there does exist a differential pressure across an internal component that is in some way designed for it, the maximum differential allowable can presumably be calculated, if it is of interest.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

On edit: added text in bold