Check Valve Help!

[TazJMT]

Hello All,

So I put an inline chlorinator into my system last year-above ground 21 foot round pool. At the end of the season last year after only a few months, I found that my check valve had failed and it was letting the chlorine go back into the filter. I went back to the pool store and they replaced it for free. This year, I again put the check valve in (between the filter and chlorinator) horizontally (and facing the right way and all that) and tested it first by taking the plumbing and putting a garden hose into the end that would be the return end. I turned the water on and it worked perfectly, didn't let water exit on the other side (filter side), only backed up the water toward the return side. 7 days later, I had a suspicion it had failed again and took the plumbing system out and did the garden hose test again. this time, it let the water through the other side (check valve flap not engaging).

I am using trichlor pucks if that matters. Also, the chlorinator is mounted on the ground below the level of the filter and the return on the pool (via 90 degree elbows to get it down there). The brand is FLO and it is a flapper type check valve.

Is this the wrong kind? What am I doing wrong here? The pool store said they will give me another kind-the type that is always closed and needs front pressure to open rather than the flap that is always open and requires back pressure to close. But I am afraid this kind that needs front pressure to open will restrict the flow into the return because of the valve mechanism in the center of the valve (the flapper kind which is very open allows maximum flow)

Please help me, this is VERY frusterating!


Update:
does it matter how close I put the check valve to the chlorinator? The pool store guy that gave it to me to replace the old one said it should be about a foot away. Mine was only a few inches.

For reference, this is the one he gave me. http://www.amazon.com/Pentair-R17228...heck+valve+pvc

It's got a spring, but it's not a flapper like the Jandy, it's kinda of like a smaller circle instead the pipe that opens up when pressure hits it. I am worried about the flow I will get from it. The directions say it can be mounted in any orientation-does that mean I can do vertical also? gravity would be working against the check valve staying closed in that situation, but the spring feels REALLY tight. I would love to keep it vertical as that would give me distance from the chlorinator and less visible piping as I could hide it behind the filter. I am doing this either tomorrow or the next day, so if someone sees this, that would be great

[PoolDoc]

That particular Pentair check will restrict your flow a LOT. That *might* not be bad, since on AG pools, the pumps are often oversized and the filters undersized. But it also could essentially turn your flow off!

I'd recommend this one, instead: Jandy 7305 2-Inch to 2-1/2-Inch Check Valve


And, it's not necessary to put it right next to the feeder -- you can put it next to the filter instead.

One more tip: if you use a pump timer, it's a bad idea to have the pump run only 1x per day. It's much better to run 2 x 3hrs, than to run 1 x 6hrs. There are several reasons for this, but in your case the most relevant one is that each pump cycle will flush out built up gases from the feeder.

. . . membership updated.

[TazJMT]

That particular Pentair check will restrict your flow a LOT. That *might* not be bad, since on AG pools, the pumps are often oversized and the filters undersized. But it also could essentially turn your flow off!

I'd recommend this one, instead: Jandy 7305 2-Inch to 2-1/2-Inch Check Valve


And, it's not necessary to put it right next to the feeder -- you can put it next to the filter instead.

One more tip: if you use a pump timer, it's a bad idea to have the pump run only 1x per day. It's much better to run 2 x 3hrs, than to run 1 x 6hrs. There are several reasons for this, but in your case the most relevant one is that each pump cycle will flush out built up gases from the feeder.

. . . membership updated.

Well I put the pentair on yesterday, but wanted to check the flow (or lackthereof) in an interesting way. I detached part of the plumbing from the old setup I had with the failed check valve. So all i had left on the return end was some pvc, and elbow, and the check valve. I then turned the pump on for 3 seconds-ish to see how much water would come out. I thought this was the best way to literally see how much water it would allow through. Obviously alot since i basically wasnt stopping back flow anyway. I then built the new plumbing with the new check valve and did the same test-just had an elbow, some PVC, and the new check valve. To my surprise, the flow was very close. Not exact, but close. So i installed it, did all the cementing, and let 'er rip. The flow is about 90% of the old one, clearly plenty. So that was happy.
I installed the check valve about 2 feet of PVC away from the filter (mostly vertical pipe) and 1 foot away from the chlorinator (horizontal) . The check valve is installed in a horizontal orientation. It is closed with 2-3 pounds required to open the spring, which opens the circular type enclosure. Looks like it would restrict flow alot, but it doesnt

Oddly enough, i looked at the old FLO check valve and you can see the black rubber-ish ring wrinkled like bacon after just 1 week. How could that happen? Is that a very low quality valve? This is it here-flapper, no spring http://www.amazon.com/Flo-Control-Wh...vc+check+valve

And I am also happy to report that I do have the filter on a timer 2 times a day, from 7-10am and 7-10 pm

My pump is a Hayward 1 HP and my filter is S166T Hayward sand- 21 FT round above ground pool

[PoolDoc]

The gasket material is very important. Some common rubber materials used with potable water are not at all compatible with the high level of chlorine found in 'leak-back' from a trichlor feeder. Nitrile rubber and neoprene are both common but are not at all resistant to acidic solutions of chlorine. EDPM is much better, but Viton (a fluorocarbon) is best. When I've installed valves in commercial settings, Viton was always my go-to elastomer if it was available. I think that particular check valve does have a Viton O-ring seat (often a weird brown color).


Anyhow, I'm glad the check valve you had turned out not to be a problem.

[TazJMT]

The gasket material is very important. Some common rubber materials used with potable water are not at all compatible with the high level of chlorine found in 'leak-back' from a trichlor feeder. Nitrile rubber and neoprene are both common but are not at all resistant to acidic solutions of chlorine. EDPM is much better, but Viton (a fluorocarbon) is best. When I've installed valves in commercial settings, Viton was always my go-to elastomer if it was available. I think that particular check valve does have a Viton O-ring seat (often a weird brown color).


Anyhow, I'm glad the check valve you had turned out not to be a problem.

I actually couldnt see any color for the gasket on the new check valve. It was hard to reach my finger all the way in and I know there must be some sort of gasket, but i couldnt see it or feel it. The directions on this valve specifically mention stopping corrosive liquids/gasses, so that gives me hope that it will last some length of time. I'll update in a few weeks to see how it is lasting.

Hopefully, the FLO valve i used last year that surely failed within a few weeks didn't really mess my filer up too much

[PoolDoc]

I don't think the back flow from the feeder would be damaging to most filters.

[TazJMT]

I don't think the back flow from the feeder would be damaging to most filters.

Oh-well then I have to ask-why in the world was it suggested by so many people that I use one if the chlorinated backflow water wouldn't do damage? That's frustrating!

[PoolDoc]

It destroys heaters and any equipment with metal such as a gate valve. It would probably damage an SWCG.

I personally never used check valves when I installed feeders years ago. BUT, in this market pumps usually run 24/7 (afternoon thunderstorms mess pools up on a daily basis), and it wasn't usually an issue.

[TazJMT]

It destroys heaters and any equipment with metal such as a gate valve. It would probably damage an SWCG.

I personally never used check valves when I installed feeders years ago. BUT, in this market pumps usually run 24/7 (afternoon thunderstorms mess pools up on a daily basis), and it wasn't usually an issue.

SWCG? Whats that

[PoolDoc]

Salt Water Chlorine Generator.

SWG is more common, but those devices do NOT generate salt water, so I kinda banned that term here, among the mods.