Beware of Hasa's check valves

[Water_man]

When I first installed my LQ I removed the check valves because the initial flow was slow and it was posted everywhere that if your equip is above water level you don't need'em. This is also what the tech from HASA said.
After the installation I noticed that my pool was fed by not only FC, but also by DE too.
When the pump shuts off, the LQ drained into the inlet line, bringing air into the system. I noticed the pump basket got filled with DE. (I have the Hayward Super Pump with a transparent basket cover.)
I reinstalled the check valve into the "In" line. There was no flow reduction and no more DE running back into my pool!

 

[pooltime]

Re: Liquidator's check valve is needed on the intake line

I noticed some DE flowing back into my pump as well (have same pump as you). I will install my check valve on the inlet side and see how it works. Did you use the one that came with the LQ or a replacement one from elsewhere?

 

[Water_man]

Re: Liquidator's check valve is needed on the intake line

I noticed some DE flowing back into my pump as well (have same pump as you). I will install my check valve on the inlet side and see how it works. Did you use the one that came with the LQ or a replacement one from elsewhere?

I used the original one. No DE problems or pump not priming ever since.

 

[Water_man]

As mentioned above I installed the original check valve in the "in" line.
Recently I noticed that after pump shut off air comes to the system and the pump basket is no longer air-and-DE free. I checked the check valve and lo and behold - it goes both ways. These valves go out of order with time. You can't assume that if you check it OK when you install it will go on forever.

 

[JasonLion]

This might be an effect of the white stuff. Sometimes a quick rinse in dilute muriatic acid will get it working again.

 

[Water_man]

This might be an effect of the white stuff.

This check valve is in the "in" side of the system, where FC level is pool level and there's no WS buildup. The valve should have not been in contact with any LQ top layer water had it been working properly in the first place.