VESSEL MAWP VS TEMP 1

[skylarknight]

Hi I'm wondering if there is a Vessel MAWP vs. Temperature rating, much like the ASME B16.5 flange pressure vs temperature (attached). We are installing a separator on a line which is expected to be running at 80 DegC so I'm wondering if I should have the PSV set point lowered.

 

[1gibson]

Does your vessel not have flanges on it?

 

[skylarknight]

of course it has flanges on it... MAWP of vessel is 1440 psi up to 100DegF. 40 PSI lower than that of flanges. So I'm expecting the MAWP of the vessel to be lower than the flange @80DegC

 

[LittleInch]

Your vessel should be certified for a max pressure at a maximum temperature.

Your post implies that you are operating either at a high pressure, but lower temperature or you're planning on increasing the operating temperature above the design temperature?

Either one really needs a re-certification not a simple chart of pressure vs temperature.

All flanges to a certain spec and rating and material are the same, but every vessel is different.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[skylarknight]

Thanks, Confirmed The vessel will have to be re certified.

 

[1gibson]

If your vessel/flanges are 316 stainless steel, then 1440 psig is the full flange rating @100*F.

 

[SnTMan]

Once the UNITS are straightened out, we can perhaps have a meaningful discussion.

Regards,

Mike

 

[GenB]

Your vessel does not have the rated temp. I believe the new NBIC allows re-rating down or de-rating but not re-rating upwards. Also check with your jurisdiction as they are the one as who authoriz re-ratings.