checking a compressor

[Greek_engineer]

hello!!
I want your opinion about the way I tried to test a compressor.

I wanted to know if a compressor was broken and I put a manometer at its discharge pipe.

I took as a result high pressure 14.8 bar and then I stopped the compressor.

I noticed that the pressure had the ability to remain at that point (14.8 bar) for about a quarter of time.

Then I was sure that the compressor was ok!

What is your opinion about testing a broken compressor.

Thanks!10706

[Greek_engineer]

notice : I had already removed all the pipe connections from the compressor and the discharge pipe of the compressor was directly connected on my manometer.

[moideen]

I think you are trying to test your compressor. I don’t know what you mean “broken compressor”. I think you mean the seating of compressor valves. If pressure is steady for a while; your compressor valves are ok.

[PaulZ]

If as moideen has said you are referring to the valves then the best way would be to see if you can get the suction into a vacuum say -50 kpa by closing the suction stop valve and see how quickly the pressure rises, make sure any oil return is shut.
This will give you some idea on the condition of the suction valves and will tell you if the discharge valves are sealing.
If you only look at the discharge pressure this could give you a false reading if the discharge check / non return valve is leaking as the discharge pressure will stay high for a long time.
If in doubt the best way is to lift the heads and visually inspect valves for broken rings.
Regards
Paul

[Greek_engineer]

worth mentioning, I used this method on a domestic refrigerator charged with R-134.

[1mikeefc1]

I would say you have proved the compressor does pump to a certain degree but not that it's pumping efficiently or enough for the refrigeration system to work.

[install monkey]

usually u test on the low side to ensure it will pull a 13 inch vac- within a minute- 2 minutes if its on the system- and see if it holds when stopped

[Greek_engineer]

ok. I used that method because I was taught it at a seminar related to inspect malfunction on compressor and its valves.
Does any of you have any special document about all mentioned methods above?

[install monkey]

http://gmrc.org/documents/GUIDELINEFORFIELDTESTINGOFRECIPROCATINGCOMPRESSORPERFORMANCE.pdf

[Greek_engineer]

Thanks a lot!

[sendhilkmar]

Remove the piping’s except condenser and connect the pressure gauge at the condenser out let . Supply nitrogen or dry air at 2 bar pressure thru the compressor suction tube. Run the compressor until pressure builds up to 12 bar in teh condenser then stop the supply and switch off the compressor. Check the leak back for a minute; if the leak back reading is more than 2 bar then you can conclude as pumping failure

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[StarCat]

I think you need to get gauges calibrated in PSIG because 1 BAR is too large a degree of change with respect to refrigeration work.

[shanonmethod]

hello!!
I want your opinion about the way I tried to test a compressor.

I wanted to know if a compressor was broken and I put a manometer at its discharge pipe.

I took as a result high pressure 14.8 bar and then I stopped the compressor.

I noticed that the pressure had the ability to remain at that point (14.8 bar) for about a quarter of time.

Then I was sure that the compressor was ok!

What is your opinion about testing a broken compressor.

Thanks!10706

In my opinion Change the piping and bottom valves to check broken compressor working.While checking it attached another compressor on it and see the difference between both,you can easily check and find its working performance.:cool: