In line check valve?

[ethany]

Can someone tell me what an in-line check valve does and is it absolutely necessary to have one? I have one now in between my heater and my salt water chlorinator. I am in the process of installing a new saltwater chlorinator and my old check valve cannot be reused because the couplings are too close to the check valve.

Thanks

 

[Isaac-1]

They prevent backflow, most importantly they prevent water flushing back through your filter depositing junk in the pump. If it is needed depends on a number of factors mostly relating to the height of the water relative to the equipment, for example if your pad is below the surface level of your pool you certainly need one.

 

[Bama Rambler]

Most mfg's suggest installing a check valve between the swg and the heater or filter to keep any gases from backing up into the equipment. The actual need for it depends on the individual plumbing arrangement.

 

[Melbourne]

They prevent backflow, most importantly they prevent water flushing back through your filter depositing junk in the pump. If it is needed depends on a number of factors mostly relating to the height of the water relative to the equipment, for example if your pad is below the surface level of your pool you certainly need one.

Is this true if you are using a regular hayward sand filter?

I am in the middle of re-plumbing my pool, and the new equipment pad is now about 16" lower than the pool water surface, and I was not planning on a check valve. When opening the pump lid, I planned to first shut the jandy valve that I am installing on the return line.

By your recommendation however, it sounds like you are saying that I should install a check valve on the return line - is that correct?

Great forum by the way. Lots of info here.

 

[Isaac-1]

You should if for no other reason than pump strainer baskets are a common source of leaks, and you probably don't want to come home one day to find hundreds or perhaps thousands of gallons of water has drained out through yours.

 

[Melbourne]

Okay I shall put one in then.

Your response begs the question though: would not that same thing occur through the suction lines anyway, on which a check valve against flow towards the pump cannot be installed?

 

[Isaac-1]

Yes, it could, but would partly depend on your plumbing setup, if you have a skimmer only or main drain plumbed through the skimmer as a vacuum break then it would stop loosing water when the skimmer ran dry, instead of the height / depth of the return fittings or ground level which ever is higher.

 

[Melbourne]

Thanks guys.