check valve failing, NO FLOW

[dadszx7]

All right here we go....
I've got a tru vu 55 gallon with about 20 gallon sump. With out a check valve, the sump gets very close to over flowing with a simulated power outage. Right after the return pump, I've place a hard a plumbed PVC non-clear check valve bought at the local hard ware store. I've lost about 97% of flow out the 4 return heads. After the check valve, I've got a shut off valve, which goes to 4 parts of the manifold, and they each have their own shut off valves. Which go the four return heads. I've already bought a clear shut-off valve on the big

[hr]
site. When is comes in, I'll install it. It's the flapper style.
Thoughts///////////////
dadszx7

 

[salty blues]

I use one of the clear flapper style cv's on my set-up. It works great. No appreciable flow loss & no back siphon. ymmv

 

[scsinet]

Well those non-clear check valves are spring style. They require a lot of head pressure from the pump to operate, so that's where your flow is going... fighting the spring.
All check valves will eventually fail... and they'll almost certainly fail when you aren't around. Siphon holes are much more reliable. I've had two spring style and 2 flapper style valves fail on me... I just don't trust them anymore.

 

[trippkid]

Originally Posted by SCSInet
Well those non-clear check valves are spring style. They require a lot of head pressure from the pump to operate, so that's where your flow is going... fighting the spring.
All check valves will eventually fail... and they'll almost certainly fail when you aren't around. Siphon holes are much more reliable. I've had two spring style and 2 flapper style valves fail on me... I just don't trust them anymore.
Agree 1000%, don't trust the check valves, anti-siphon holes are the way to go, IMO.
Matt

 

[dadszx7]

So, I changed to a clear check valve and have add a seperate refugium that I built and added to my sump. Connecting the two with bulkheads and clear tubing. Now no issues with overflow. When the check valve fails, I will remove and not replace it.

 

[acrylic51]

Originally Posted by SCSInet
Well those non-clear check valves are spring style. They require a lot of head pressure from the pump to operate, so that's where your flow is going... fighting the spring.
All check valves will eventually fail... and they'll almost certainly fail when you aren't around. Siphon holes are much more reliable. I've had two spring style and 2 flapper style valves fail on me... I just don't trust them anymore.
I agree with SCSInet the spring ones are harder for the pump to push against and does affect your headloss from your pump....I do however like the flapper type check valves, and will only use the clear rebuildable ones, but like stated they do fail, but it's another safety precaution that I've always used....
You stated that when you shut your pump down it almost overflows???? If that's the case your water level is set incorrectly in your sump as well.

 

[myzislow]

definitely ditch the check valves and switch to some anti siphon holes drilled into your return. I have set up 3 tanks this way and never had the anti siphon holes fail yet. All you have to do is make sure they stay clear up salt build up/debris and that's it.