I've got a wicked air leak somewhere on startup this year. I'm running to get a replacement strainer pot oRing today for the pump (Pentair Whisperflow). I opened the suction ball valves (2 1 skimmer 1 pool bottom) and one of the valves is completely missing the ball seat and oRing. I had the pump replaced about 3 years ago before I decided to take on being my own pool man and I'm betting they just tightened the joint up with some wrench instead of replacing the parts they lost and I never knew better. I undid the unions last year in order to more easily fill the pipe running to the bottom of the pool with antifreeze when closing. I'm betting I didn't jack it down like they did so now I have an air leak.
So my question is, I found the mfr of the valve and they have rebuild kits for the valves (seats and o rings). But they sell 3 different version and I don't know which type of oRing I need. It looks like it is related to the TYPE of material the oRing is made of.
http://www.barrettsupply.com/barrett/sp ... kits.htm#3
Those are the rebuild kits but I don't know if I need BUNA-N, EPDM or VITON/FKM oRings.
Does anyone know what should be used in a pool valve? Or does it not matter?