We have seen that many a times these valves do leak & the entire NH3 has to be wasted. WE have seen Danfoos Quick Drain valve & is really good. But that comes with a price tag & hence all try & avoid that.

We are trying to put up TWO drain valves so that One shall be always open & other shall be operated for draining the oil etc. in case of eventual leak, atleast we can close the back up valve. Any better idea than this?

Same is the story with Pr Safety valve. There also we get Dual safety valve operating on a similar principal as above. Again any better idea in this concept?