MAWP of API 12A tanks/ IFR ?
MAWP of API 12A tanks/ IFR ?
(OP)
Good morning all, I hope all is well. I have been tasked to investigate the MAWP of 70,000BBL tanks built to API 12A (old riveted tanks, IFR with shell). The tank has low pressure relief devices on the floating roof set at minimum for the pressure (0.5 Oz) and vacuum (O.5 Oz) to protect the seal when emptying the tank completely.
Q-1: Is it commonly seen to have low pressure relief devices on IFR?
Q-2: Will the shell of the tank be subject to API 2000?
Q-3: Opinions on determining the MAWP of API 12A tanks?
Your time and advice is greatly appreciated. Thanks,
Avg
Q-1: Is it commonly seen to have low pressure relief devices on IFR?
Q-2: Will the shell of the tank be subject to API 2000?
Q-3: Opinions on determining the MAWP of API 12A tanks?
Your time and advice is greatly appreciated. Thanks,
Avg





RE: MAWP of API 12A tanks/ IFR ?
IFR seals do not need pressure / vacuum relief - they are not that tight or sensitive
API 2000 does not apply because IFR tanks should have circulation vents, see API 650 Annex H
MAWP for an IFR tank should be atmospheric, because of the circulation vents
RE: MAWP of API 12A tanks/ IFR ?
Have you seen any case in which a shell has been constructed with out circulation vents?
If so, the shell would either be protected by Emergency Vents and/or frangible roof joints I presume?
Thanks again,
Avg.
RE: MAWP of API 12A tanks/ IFR ?