What is this plumbing part? Air break?

[Reclayborn]

I need to replace a check valve to the right of this, and PO was nice enough to but all of the connections/valves/checks right up against each other so I need to replace the the entire run. I have purchased all the parts except this gray thing. I have another on the waste line and I think it is an air break, but nothing I search for looks like it. I think it threads into the PVC with a 3/4" fitting. I showed this photo to the local pool supply shop and was told "Not sure what that is". That's the second item I have shown them, so need to find a new shop. Or if it does thread out I'll try to get it out, but don't want to wrench on it and break it then not be able to replace it.

 

[ajw22]

Pool systems do not have air gaps or backflow preventers other then at an autofill connection to the house water.

Did you build the pool or was there a prior owner?

They may be plugs that were used for chemical injections from a Stenner pump or the like.

 

[1poolman1]

That appears to be the remains of a flow switch, possibly Hayward, based on what's left of a label. The wires are cut off very close to the body. It is a 1/2" thread, not 3/4". The system may have had a Hayward SWG at one time and this was left over when it was removed.

 

[Reclayborn]

That appears to be the remains of a flow switch, possibly Hayward, based on what's left of a label. The wires are cut off very close to the body. It is a 1/2" thread, not 3/4". The system may have had a Hayward SWG at one time and this was left over when it was removed.

Gotcha, I'll check for wires. If that was it then I don't need it and can skip that PVC part.

Thank you both for your help.