Unknown Device In Pad Plumbing

[revitup]

I don't know what this device is in my pool plumbing. It's in the line coming out of the HP. Can someone enlighten me?

 

[PoolGate]

Looks like a one-way (check) valve.

 

[JamesW]

Thread-On Cover - CMP

www.c-m-p.com

 

[revitup]

Thanks much.
By ‘socket’ and ‘spigot’ that’s just in and out?
Am I supposed to service that periodically? If at all?

 

[JamesW]

The end connection of a fitting that is to be assembled into another fitting is called the “Spigot.” The spigot end of a fitting has the same outside diameter as pipe. The common female connection of PVC fittings is referred to as the socket or hub, and the spigot end of a fitting can be inserted into a Hub or Socket.

What is a Spigot (SPIG), and how does it differ from Socket and Hub? | U.S. Plastic

What is a Spigot (SPIG), and how does it differ from Socket and Hub? The end connection of a fitting that is to be assembled into another fitting is called the “Spigot.”

www.usplastic.com

The valve has both spigot and socket connections. PVC pipe slips into the smaller socket connection and a PVC coupling slips over the larger diameter outside spigot end.

The check valves last a long time as long as they're not near a tab feeder. If they fail, the top can be unscrewed and the guts replaced. I'm pretty sure that yours are CMP, but verify by looking for markings on the valve.

When you look through the clear top, you can see the spring and flapper assembly. The flapper should move up on the hinge as water begins to flow and it should go back down as the water stops flowing.

 

[revitup]

Very interesting thanks. Funny how I’ve never heard those terms used in that context before. Always learning
Guess I’ll glance at it occasionally like I do the pressure gauge.

 

[pjt]

It's a check valve functioning as part of the bypass plumbing for your HP.