YungPlantEng
Chemical
- Jan 19, 2022
- 84
We have a ASME VIII vessel that used to be run on high pressure. What’s the standard for formally rerating this to a low pressure tank to avoid the need to have a PRV? This tank already has a rupture disc that we’ll keep and it has a control valve for out/inbreathing that goes to a common header - the PRV doesn’t have design calculations and isn’t very operable.
It’s a PSM vessel if that changes anything, obviously we would have to revalidate the PHA but from my standpoint the only credible overpressure case (beyond a rupture disc fail closed, control venting failure, and interlock failure) is an external fire case. Not sure if rupture discs and emergency procedures are enough to counteract that but it’s what I’ve seen for other low pressure vessels that contain low boiling point non flammable substances
It’s a PSM vessel if that changes anything, obviously we would have to revalidate the PHA but from my standpoint the only credible overpressure case (beyond a rupture disc fail closed, control venting failure, and interlock failure) is an external fire case. Not sure if rupture discs and emergency procedures are enough to counteract that but it’s what I’ve seen for other low pressure vessels that contain low boiling point non flammable substances