Return plumbing question

[joshyross70]

I purchased an Eshopps small overflow with a 1inch return. I want to place a ball valve and can't seem to find the right adaptor for it since the threads seem pretty small. Has anyone plumbed one of these overflow boxes? What did you use?

 

[Flippers4pups]

Bump

 

[mfinn]

I purchased an Eshopps small overflow with a 1inch return. I want to place a ball valve and can't seem to find the right adaptor for it since the threads seem pretty small. Has anyone plumbed one of these overflow boxes? What did you use?

Is this the one that you drill?