Code Case 2211
Code Case 2211
(OP)
Case 2211-1 says we can use system design in lieu of a relief valve to protect a pressure vessel if "The vessel is not exclusively in air, water, or steam service unless these services are critical to preventing the relase of fluids that may result in safety or environmental hazards."
We are looking at an air receiver designed to 150 psig being used in a system fed by a 40 psig centrifugal compressor with a 45 psig relief valve. The air is used as a utility. Since the vessel is exclusively in air service, it looks like CC2211 tells us we must have a relief valve. Is this correct?
We are looking at an air receiver designed to 150 psig being used in a system fed by a 40 psig centrifugal compressor with a 45 psig relief valve. The air is used as a utility. Since the vessel is exclusively in air service, it looks like CC2211 tells us we must have a relief valve. Is this correct?
Larry





RE: Code Case 2211
Larry, I am not familiar with Case 2211-1, but this passage seems to indicate using a HIPPS (High Integrity Pressure Protection System).
From a practical point of view, using a PRV on an instrument air receiver is most likely cheaper, and more common. I have not heard of a HIPPS on an air receiver.
Anyone else out there know of one?
RE: Code Case 2211
RE: Code Case 2211
I'd still like to have a discussion about a pressure vessel in a system with a PSV on adjacent piping, though. Would 2211-1 apply to a case like that?
Our local jurisdiction is NASA, so that's another complication.....
Larry
RE: Code Case 2211
"UG-125 GENERAL
(a) All pressure vessels within the Scope of this
Division, irrespective of size or pressure, shall be
provided with pressure relief devices in accordance
with the requirements of UG-125 through UG-137."
Our specific situation (not a receiver, but a compressor aftercooler) looks like it's covered by UG-125(g), so that our 150 psig shell fed by a 40 psig compressor with 50 psig PSV does not need its own relief valve:
"(g) The pressure relief devices required in (a) above
need not be installed directly on a pressure vessel when
the source of pressure is external to the vessel and is
under such positive control that the pressure in the
vessel cannot exceed the maximum allowable working
pressure at the operating temperature except as permitted
in (c) above (see UG-98)."
I've used this provision to install filter vessels rated at 150 psig in a line protected by a 140 psig PSV on the compressor discharge - with no intervening valves.
Comments, please?
Larry