I need a check valve

[Limpit]

Went to local hardware stores today looking for a saltwater safe check valve to plumb into my return line. Right now if the power were to go out I would end up with about 30 extra gallons of water spilling out of my sump. I am using 3/4" tubing because I do not want to hard plumb the thing with pvc. I am looking for a size that I can get some hose barb ends to attach to it that will accommodate the 3/4" tubing. The local hardware stores do not have anything besides large sump pump check valves. Who's got what I need?

[Stevan]

http://www.usplastic.com/catalog/default.asp

[Fast Fred]

You should consider arranging your plumbing in such a way that you don't NEED a check valve. They have been known to fail.
JMO

[Neurosis]

Marine Depot carries check valves. Pretty much all of their check valves are slips, but you could just attach short pieces of pvc then put barbs on them. I'd still go with the suggestions above, in that you should always prepare for the worse, cuz the check valves may get stuck open.

[drjrose]

Originally posted by Limpit
The local hardware stores do not have anything besides large sump pump check valves. Who's got what I need?

I use the ones from Home Depot.

[Limpit]

Originally posted by drjrose
I use the ones from Home Depot.
Went to Home Depot last night, all they had was 1 1/2" and 1 1/4" sump pump check valves. While I could make one of those work I do not want a bunch of fittings attached to the thing to make it work. I am going to get a slip connector type from Marine Depot or Foster and Smith and attach barb ends to it.

[Limpit]

Originally posted by Fast Fred
You should consider arranging your plumbing in such a way that you don't NEED a check valve. They have been known to fail.
JMO
How would you prevent a back siphon by arranging the plumbing when the return pump is in the sump without using a check valve?

[redspot321]

Have your return plumbing just below the surface of the water. When your power fails, you will suck water breifly then air once the water level drops a bit.

[Limpit]

Originally posted by redspot321
Have your return plumbing just below the surface of the water. When your power fails, you will suck water breifly then air once the water level drops a bit.
I will have to do some water level adjustments to the tank in order to do that. Right now I only have about 3/4" from the tank lip to the water surface, but it could be adjusted. My return pipe goes over the top of the tank and sits about 2" below the surface right now. That would mean quite a bit of overflow if the power goes out on a 125 gallon tank.:eek1:

[sarduci]

Drilling a small hole or 2 at about 1" below your water surface would drain about 5 or 6 gallons at the most. Even if it drained 10, it still would be less than your check valve not working and dropping 30 gallons anyway.

[Limpit]

Originally posted by sarduci
Drilling a small hole or 2 at about 1" below your water surface would drain about 5 or 6 gallons at the most. Even if it drained 10, it still would be less than your check valve not working and dropping 30 gallons anyway.
Thanks for the hole drilling tip, I am going to try that along with a check valve.

[drjrose]

Originally posted by Limpit
Went to Home Depot last night, all they had was 1 1/2" and 1 1/4" sump pump check valves.

Must have gotten someone unfamiliar with the plumbing area. They are next to the red handled PVC cut off valves. You can get an anti-siphon valve that you put in line at the highest point of the return line. They break the siphon when the forward flow cuts off are a good backup.

[Neurosis]

If you do get a check valve, you'll want the flip type checks. Most of the ones I've seen at HD are spring loaded, which requires extra pump pressure to keep the check valve open. Also, the springs are made out of metal.

[Paul79936]

The HD type spring check valves reduce your return flow and have metal in them.

These are what I would buy:

http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/8229/cid/2043

[sjm817]

I use the true union type as posted above and have had very good luck with them. I also drill the hole in the return just below the water level. Cant be too safe.

[Limpit]

I drilled a hole in the return pipe about 1/8" below the water surface. Unplugged the pump and very little backflow. I am going to forget about the check valve now. Thanks for saving me some money, now I can spend it on some more livestock!