API 650 Low Pressure Tanks MAWP/V calculations

[msshah17]

thread794-149937

I have some difficulty in calculating the MAWP & MAWV of low pressure Storage Tanks. I had spent long hours on the Pressure Vessel Handbook and I'm still not sure about the relevance of my calculations. I have almost a hundred tanks to determine the MAWP/V, some conical and dome type roofs, for one of our major clients before sizing pressure relief devices for those tanks. Please advise.

Can some one can help me out with API 650 Low Pressure Tanks MAWP/V calculations OR Excel spread sheet, please

Thanks.
Mech engineer,
MS

 

[JStephen]

First off, MAWP is an ASME term and is not well-defined in API.
Some questions, though: Are you sizing vents based on the tanks' pressures as already defined? Or are you re-rating every tank?
Do you have the original drawings and design calculations for the tanks? Original vent set pressures, flow rates, etc.?
Note that in the last several editions of API-650, the pressure design and means of combining that with wind and seismic have changed, so if you evaluate per the current standard, you'll get different results than you would using the as-built standards. If you lack calculations or drawings or nameplates, it could get considerably more involved.

 

[msshah17]

Thanks for reply, J Stephen
You are correct, it is not well define. I do have some information from name plate so I am making some assumption on Tank software and build the model.

Are you familiar with Tank software? I need some explanation if you are familiar.

Please let me know. Again, I appreciate your time and help.