Water hammer (check valve)

[A. Grandis]

Basically when I turn off the return pump, the check valve keeps making noise, the flapper goes up and down many times, and water still makes it's way in the sump. Some times for a long time until it stops.
Tried move the tubes around, flipped the check valve and also moved it to the side. Didn't work.

Did you ever had the problem?
How can I solve it?
Thanks,
Grandis.

 

[power boat jim]

They generally get dirty and become unreliable. I would not rely on them to prevent an overflow. Removing and cleaning them may help.

 

[ca1ore]

Check valves are essentially useless for a bunch of reasons; one of which you are experiencing. If you feel you must use one, the Y or ball checks tend to not vibrate like the flappers do. However, designing your return plumbing so that a check is unecessary is best.

 

[A. Grandis]

You're right! Besides that, biofilm and other organisms will eventually intervene.
Yep, I was thinking of redoing the plumbing here, back to the original.
I'll probably get back to the old style with the return pipe close to the water surface, so air can brake the back flow.
Any other tips?
Thanks,
Grandis.

 

[Bilk]

Basically when I turn off the return pump, the check valve keeps making noise, the flapper goes up and down many times, and water still makes it's way in the sump. Some times for a long time until it stops.
Tried move the tubes around, flipped the check valve and also moved it to the side. Didn't work.

Did you ever had the problem?
How can I solve it?
Thanks,
Grandis.

I have a "flapper" check valve on my return line. I installed it to prevent water draining down to the elevation of the two returns inside the tank when I shut the return pump off for feeding, etc. Yes it does need to be cleaned from time to time or it will foul and fail due to organic buildup. If I were to purchase a new tank, I'd probably have the builder place the return bulkheads a bit higher than what they currently are and possibly avoid the use of a check.

The hammering you're experiencing could be caused by organic buildup, which is preventing the valve from fully closing, which in turn is allowing water to force passed the check. It could also be from air which is being drawn down in the skimmer, putting negative pressure on the flapper. I have a bean animal overflow and it works under full siphon so no air enters into the pipe toward the sump.

 

[Bilk]

The hammering you're experiencing could be caused by organic buildup, which is preventing the valve from fully closing, which in turn is allowing water to force passed the check. It could also be from air which is being drawn down in the skimmer, putting negative pressure on the flapper. I have a bean animal overflow and it works under full siphon so no air enters into the pipe toward the sump.

"Skimmer" referenced in my post should read "overflow". We're not talking pools here

 

[A. Grandis]

Thanks for the replies!

Problem was easily solved by removing the check valve for good and replacing the ¾" return tube!!!
Like the old days, I just placed the return pipes closer to the surface and it is the best I've ever did!!! This time there are 2 bulkheads on the back glass, close to the surface. I connected some of those those Loc-Line modular segments and placed them half way out of the water on each side of the tank.

If you have a check valve please rethink about your plumbing. It may be way easier to remove them and redo your return than you think!! Now I know that if no more electricity I can guarantee there will be no problems.

Aloha,
Grandis.