Pressure relief valve question

[coldmilk]

Where should a pressure relief valve be placed on the "high side" of a refrigeration system, liquid or vapor?

[jacob perkins]

Hey coldmilk,
I dunno but will take wild guess.. and let some X refer guy correct me,if need be.

I will say discharge.(vapor)

[icemeister]

This answer to this question is most likely found somewhere within the ASME Pressure Vessel Code, the ASHRAE Safety Code and the like.

In my experience the codes address the venting of pressure vessels, so I'd vote for the relief valve's location to be on the receiver....at or near the top where vapor is most likely present. If there are large lowside vessels like chillers, accumulators, low-pressure receivers, etc.....they will require reliefs as well. Again, I've only seen the reliefs located at or near the top, where there's vapor.

So it's possible that you need relief valves in more than one point in the system and both on the high and low sides.

[rimek]

I'll also vote for on the discharge line - vapor- and not able to be valved off, excepting the discharge service valve on the compressor. I have seen passed installs where the prv was on the water-cooled condenser shell taps. Also be aware of the need to remote vent line if in a confined space.

[R12rules]

once again...Ice is right.

[condenseddave]

Originally posted by icemeister
This answer to this question is most likely found somewhere within the ASME Pressure Vessel Code, the ASHRAE Safety Code and the like.

In my experience the codes address the venting of pressure vessels, so I'd vote for the relief valve's location to be on the receiver....at or near the top where vapor is most likely present. If there are large lowside vessels like chillers, accumulators, low-pressure receivers, etc.....they will require reliefs as well. Again, I've only seen the reliefs located at or near the top, where there's vapor.

So it's possible that you need relief valves in more than one point in the system and both on the high and low sides.

Basically, there has to be one for every pressure vessel.

Doesn't matter what type of fluid is in it, or what state of matter it has taken on. Just has to be one on every pressure vessel...

[refrigerant_12]

ABSOLUTLY VAPOR

[condenseddave]

Originally posted by refrigerant_12
ABSOLUTLY VAPOR

Explain the use of the EXACT SAME CODE for hot water boilers, then.....

[coldmilk]

Thanks for the info fellas.