Noisy expansion valve

[R1976]

Evening all,

A site we look after has 3 Eaton Williams IPAC close control type units. One of them when switching off has an extrnally equalised TEV which makes a whining/hammering noise. From the sight glass it looks like it passes refrigerant for a few minutes after the compressor stops. Is this something I should be concerned about, will liquid pass into the evaporator and compressor when next starting. It seems to run okay with superheat okay but others say it has frozen up in the summer but I have not witnessed this.

Help very much appreciated.

[mbc]

hi
orifice of your TEV is not sealing good and passing liquid from equalized line
change it and then adjust it again

Before that close TEV about half circle see what happen

[R1976]

Thanks mbc,

I will give it a go, what would closing down by half do, won't this change the superheat?

[Neddy]

Most Close Control systems have a liquid line solenoid valve. If the system has one you need to check the valve is closing when the compressor stops.

[mbc]

Hi
It changes the super heat but this much is not too important