Check valve placement?

[t5Nitro]

Can you put a check valve under water? I have an all plastic one so it is saltwater safe right? This is for a sump/fuge.

[AZDesertRat]

Best advice is don't use a check valve period. They fail and flood your home no matter how good or where thay are placed. Design overflows and returns properly and there is no need for one.

[cmomo0128]

I second that. Dont rely on a check valve, It could end in a flood.

[t5Nitro]

So what do I do to prevent flooding?

[BeanAnimal]

Design yoru sump and overflows so that the backflow does not cause a flood. :D That may sound like a smartass answer.... but it is not :) You simply can not rely on a check valve to keep water off of your floor. If you DO, you will wish you hadn't.

[t5Nitro]

I didn't design my overflows. It is a dual megaflow overflow. It has 3 spots on the overflow where water pours in; bottom/middle/top.

[AZDesertRat]

With a Stockman or Durso standpipe close to the surface it does not matter if it has several inlets to the overflow, it will break suction with just slight backflow.

[Gary Majchrzak]

garbage can

all the water draining on those mega flows have to go over the top edge of the overflow...

[t5Nitro]

<a href=showthread.php?s=&postid=9217336#post9217336 target=_blank>Originally posted</a> by Gary Majchrzak
garbage can

all the water draining on those mega flows have to go over the top edge of the overflow...

So does that mean my overflows would break the siphon?

[AZDesertRat]

The height of the overflow breaks the siphon on the overflow side and keeping the returns close to the surface breaks the siphon on the return side. Once water gets to the bottom of the overflow teeth the flow stops falling over the overflow and once the rrturns are uncovered they also break suction. Just make sure your sump is large enough to contain whatever siphons back and never ever fill it past that point, I marked my high water point both running and power off on the sump with a Sharpie and never go any higher than that.

[t5Nitro]

How do I test a back siphon, turn the pump off?

[AZDesertRat]

Yes. Make sure you have some room in the sump and pulll the plug.Mark where the beginning level was and where the final power off level is and always maintain at least that amount of room plus a little extra in your sump at all times, even when topping off.