RTFM: CM-EP. hydrostatic testing with a refrigerant recovery pump

so… I was trying to hydro-test some newly made gear today, and I wanted to exercise the PRV’s as well.

my memory had the CMEP-OL with a 450PSI high-pressure cutoff, but the third gen CMEP-OL I managed to dig up actually quits at 350 PSI.

I dug a little further, and found a CMEP, which is the CMEP-OP predecessor (oiled!)…it tops out at 38 bar (550PSI -ish). I even found an adapter to bring it up to the 3/8in JIC I was connecting to the vessel with…but I couldn’t get it running (I’m concerned it was user error…)

So I’m either looking for someone in Eugene willing to loan me a appion/trs-21/1st/2nd gen CMEP tomorrow, or suggestions for what might be up with this CM-EP.

I could use the fine manual…and the all knowing one only wants to tell me of the newer CMEP-OL


Im off topic but that indicates its worn out? I just got my first?maybe last pump a trs21 and I think its supposed to go 550. How are you using the pump to test? Can these pumps run liquid?

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I’m using them to pump air.

Given they can handle r600 at pressures it will be liquid, they can presumably handle liquid.

System is as full of water as I can get it. Then I’m pressurizing with air. Which minimizes the stored energy should anything give way.

As far as what indicates your pump is worn out? It makes noise. It doesn’t suck like it used to. It no longer hits the high pressure limit. It leaks.

Manual contains test procedures.



that makes sense, how much pressure do you test to? and when you say give way , have you ever seen a clamp or pipe fail and blow up or is it a gasket leak? I dont have guages on the back end is a trs 21 putting 100s of psi through my cooling coil into my tank? If so that seems like the most dangerous area.

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Trying to confirm factory settings on prvs as part of a system rebuild. Those are set to break at 450 on this rig. System should never see more that 100psi in use.

Only testing the non-oem fabricated parts to 3x working pressure (350 psi so far. Ideally 450/up to PRVs).

Then doing a multi-day leak down test.

I don’t actually believe the OEM sight glasses are rated beyond 250psi. I’ll probably leak test at 200PSI.

why would the OEM spec 450PSI prvs with 250psi rated sight glasses you ask?


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crazy. I just got my first prv, some swagelok but if you turn it down its pretty loose, Il have to confirm it often, its 50 to 150 but 150 is too high. if it was set at 150 itd stay there.

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Use the lock nut once you’ve set it.

And then wire it in place.

im learning, at least now I know why its so hot on the output of the pump, extreme pressure. my swage prv has an allen screw. I think all the ice keeps the pressure way lower. Ive disconnected a hose and it wasnt 100 psi or more.

im slowly figuring this out= it puts tons of pressure against fluid but for a gas it would take a bit of time to compress and it wont be near 550.

New strategy, adjust the PRV’s to a more reasonable spot. I think they’ll only go down to 300, but that seems far more reasonable than 450PSI, and I can then test them with equipment on hand.

WhAts the largest falAnge size on that rig ?