Pressure Vessel - Full Vacuum Capability?
Pressure Vessel - Full Vacuum Capability?
(OP)
I have an existing vessel that doesn't seem to have a vacuum rating, or no minimum pressure listed. To be honest I'm not sure if that information should appear on the U-1A or not, but that's the only document I have. Well, there's also a U-4 and a U-2A but I don't see a vacuum rating anywhere.
The info on the vessel - MAWP 50 psig, min design temp -20 @ 50 psig, shell is SA-240-304L, nominal thickness is 0.250". Diameter is 84" and it's 56'1" seam to seam. Elliptical 2:1 heads.
The vessel (an amine still column) is going to run at about 240 F and 14 psig. I need to determine whether or not it can handle full vacuum should it get isolated and cool down to ambient. Is there a way to determine this?
Thank you for your help!!
-Matt
The info on the vessel - MAWP 50 psig, min design temp -20 @ 50 psig, shell is SA-240-304L, nominal thickness is 0.250". Diameter is 84" and it's 56'1" seam to seam. Elliptical 2:1 heads.
The vessel (an amine still column) is going to run at about 240 F and 14 psig. I need to determine whether or not it can handle full vacuum should it get isolated and cool down to ambient. Is there a way to determine this?
Thank you for your help!!
-Matt





RE: Pressure Vessel - Full Vacuum Capability?
Just a quick calculation: An 84" ID cylinder x 0.25" thick x about 674" long (omitting consideration of the heads), SA-240 304L, has an MAEP of about 1.3 psi. That's nowhere near full vacuum.
RE: Pressure Vessel - Full Vacuum Capability?
Thank you!!
RE: Pressure Vessel - Full Vacuum Capability?
RE: Pressure Vessel - Full Vacuum Capability?
As Tom indicates, vacuum capability can be calculated. To achieve full vacuum rating would require stiffeners on the shell roughly 6' apart, so some form of vacuum relief may be cheaper.
Cheers,
John
RE: Pressure Vessel - Full Vacuum Capability?
D*mn misspell checker.
Rather: If you cannot get the vessel "protected" by design calculation against a "full vacuum", then add a vacuum relief valve in an unisolable position, a place you cannot isolate it.