What the heck is wrong with my check valves?!? HELP!!!

[jcardona1]

Ok so I've had this issue with the plumbing on my 400g and it didnt become a huge problem until the power went out and my tank drained a few inches. and when the power came back on of course there wasnt enough water to get the sump going (good thing this is in the garage and not in the house )

Everytime i turn off the power to my pump, my check valves WONT CLOSE!! they vibrate and shake violently and the flappers go up and down and they wont seat. they allow water to trickle down into my sump which is NOT GOOD!

ive had some friends look at it and they had no idea what could be causing it. i cant figure it out either! my pump is plumbed to the sump using 1.5" piping. the outlet is 1" and split into two for the two returns. pump flows about 3400gph.

here's some pics of the setup. so any ideas what is causing this? do i need bigger plumbing? could it be the different heights of the returns?

please help!

 

[spiff]

I noticed that too. I went through two of them and they both did the same thing: they dribbled unless there was at least 3 feet of water pushing down on them.

I guess that's normal. They still should prevent a full back flooding at least. It just sounds like there isn't enough water weight on your flappers to create a good enough seal.

 

[jcardona1]

but did yours shake and rattle? mine are LOUD! sounds like my plumbing is breaking apart

 

[Superlaz]

Your pump plumbing forks into two inlets into the tank, when working properly it's no problem. When the power goes out, usually the water siphoning back out to the pump is at a greater rate than most pumps produce. You have this x two, and then coming together into one. The water backs up per say all the way up to your valves...at this point theres no suction, just water at your valves level...so the valves float open again. Once the water start coming through it repeats the process...hence the open, close, open, close. I suggest either get a second pump and have one line of PVC per pump. Or eliminate one of the ones you're currently using.

my 2 cents.


Hope that makes sense.

 

[spiff]

I just think that lowering the valves further on the line they're on will do it. That will give more water weight to control the valve. Air is trapped in the bubble of the flapper, that's what gives it the energy to bounce... but with enough water pushing down you'll be fine.

 

[jcardona1]

Your pump plumbing forks into two inlets into the tank, when working properly it's no problem. When the power goes out, usually the water siphoning back out to the pump is at a greater rate than most pumps produce. You have this x two, and then coming together into one. The water backs up per say all the way up to your valves...at this point theres no suction, just water at your valves level...so the valves float open again. Once the water start coming through it repeats the process...hence the open, close, open, close. I suggest either get a second pump and have one line of PVC per pump. Or eliminate one of the ones you're currently using.

my 2 cents.


Hope that makes sense.

thx man, i was also thinking it had something to do with the two returns lines. since i have balls valves, i was going to close one off and then cut the power to see what happens. i really dont want to add another pump so i may have to eliminate one of the returns.

but that would mean i may also have to up my plumbing to 1.5" right? since 1" may be too small for a 3400gph pump...

 

[jcardona1]

I just think that lowering the valves further on the line they're on will do it. That will give more water weight to control the valve. Air is trapped in the bubble of the flapper, that's what gives it the energy to bounce... but with enough water pushing down you'll be fine.

hmm interesting. i guess i can try this before eliminating one of the lines to see if they extra weight of the water can hold them closed...

 

[Superlaz]

Try closing one and see how it goes...shut off power and check out results. If still an issue, than moving the valves farther down is a valid option. As for return piping, I don't know how much the current size would strain your pump.

 

[jcardona1]

ok just had a thought...what do you think would happen if i leave both returns but only keep the check valve on the lower return? the upper return is high enough that all that water would go down through the overflow box anyways.

would two return lines and a check valve on only one line have the same effect?

 

[spiff]

That's an idea. Just put one between your pump and the fork to your ball valves. Those valves work horizontally too, just be sure that the flapper is oriented to be "up" when open.