Dear All,

I heard that when air-cooled condenser is above of compressor, We must use check valve at discharge pipe of compressor.
Why we should check valve ? for prevent returning liquid on top of valve plate of compressor ? Or it has other reason ?
If we use "Inverted P trap" at inlet of condenser, It is not enough for prevent liquid migration ?

Thanks if you help me in this topic.

With best regards.