View Full Version : Very noisy (discharge) check valve in scroll tandem compressors

29-05-2013, 09:51 PM

I have some condenser units with 2 scroll compressors connected in tandem. Because the compressor doesn't have a non-return valve, we mounted ones in the discharge line.
The problem is that when the condenser unit works with ONE compressor the check valve makes an incredible noise (and it looks like it is the valve from the other compressor, that is in stand-by). This happens with all the condensers (nine). So... I have excluded the malfunction of the non-return valve.
There ARE NOT valves with spring and there are mounted in the right vertical position.
Why does the ball moves up and down when the pressure in one side of the ball higher than the the other side?
Could anyone, PLEASE, help me with this problem?

Thank you!

1: I don't have a big experience in refrigeration industry (1 year) and I lead the electrical team
2: Air cooled condensing unit with R410A