MAWP and MDMT

[jtk921]

I have a pressure vessel which has a MAWP of 50 psi/FV at 350 deg F. It is also stamped with a MDMT of -20 deg F at 50 psi. Does this mean that the MAWP of 50 psi is good for the range of temperatures from -20 to 350 F?

 

[eliebl]

Yes

 

[jehan17718]

jtk921,

MDMT must correspond to MAWP.

As per General note #4 of Fig UCS 66.2 (ASME Sec 8 Div 1)....... " The construction of Fig. UCS-66 is such that the MDMT so selected is considered to occur coincidentally with an applied general primary membrane tensile stress ".... which will be governed by the pressure loadings.

Hence, we associate the MDMT with the MAWP. Please correct me in case I am incorrect/ viewpoints differ.


-jehan

 

[SnTMan]

I think you will find that UG-20 allows you to assign multiple MDMT's to multiple MAWP's, however if only marking with one set of conditions, the highest MAWP must be used to determine the MDMT.

Regards,

Mike