Leak testing new ro

[MapleCamp]

Putting the finishing touches on my new 2 by 40 , 1hp , with a procon pump and want to test it with out getting the new membranes wet , was thinking of putting about 50 psi of air through it. Would this cause any problems I can"t think of? TIA

[DRoseum]

Why not use water?

Honestly not sure but a few questions come to mind...
(1) any negative impact of compressed air on membranes?
(2) cleanliness of air (oil from compressor) and impacts?
(3) using soapy water to find bubbles?

[MapleCamp]

Why not use water?

Honestly not sure but a few questions come to mind...
(1) any negative impact of compressed air on membranes?
(2) cleanliness of air (oil from compressor) and impacts?
(3) using soapy water to find bubbles?I don't want to have to put preservative mix to store, and I keep it in an area that gets pretty cold.

[Bricklayer]

You can still run RO without membranes installed if you are worried about it. I wouldn’t try to leak test with anything other then water.
You will get equal pressure and flow comming from both concentrate and permeate lines when running with no membranes. You could put valves on the outlet lines and choke them down a bit to get a little more pressure. Be careful not to close them all the way and deadhead the system. That would be real bad. I run my RO this way when I shut down my RO for the season. Take membranes out and flush RO out with whatever permeate I have left. All valves open wide. Then I close them a bit and let it build up some pressure then back to wide open till it runs out of permeate. Most leaks I have had have been at the membrane housing caps. The threads usually suck on them. I found using good quality Teflon and liquid teflon pipe dope helps a lot. Works great on stainless fittings as well. Seem to be able to get them a lot tighter.

[carls47807]

We test all of ours with 40psi air and spray fittings with soapy water. That is equivalent to around 150psi water pressure.