1/2 in. CPVC CTS Slip x FIPT Adapter Fitting

I think you have to use CPVC with CPVC. I don't think you can mix PVC and CPVC. The diameters are slightly different.

I used the rubber seal and tape and it still leaked.

Don't see why not. Just use some teflon tape or pipe dope on threads.

Thank you for your inquiry on the 1 in. CPVC CTS Slip x FPT Female Adapter. For the 3/4 in. pipe it will be an inside diameter of 3/4 in. The pipe used with it should be 3/4 in. If you need further assistance, you can reach a NIBCO Technical Services Advisor, M-F 8am - 6pm EST, by phone at (888) 446-4226. Thank you!

No, there is no rubber seal. You will need to use some kind of seal. I use Teflon tape, and it works very well.

You can do anything you want. With that being said, I am currently in the process of using it to connect to a brass shower mixer. I have read on the internet that some say to avoid CPVC and brass because the brass can vibrate and destroy the CPVC. I tried hooking it up last night and experienced leaks in both of them that I attached to the brass. Could be user error, but I did use thread tape, and applied the gasket correctly.

Thank you for your inquiry on the Everbilt 3/4 in. CPVC CTS Slip x FIPT Adapter Fitting. 4704 CPVC-CTS adapters are NPT thread, but designed to really be used with a 4703 CPVC-CTS adapter, which is NPSM straight thread—it incorporates a rubber gasket for the flat nose of the 4704 to seal against. If you have additional questions, you can reach a NIBCO Technical Services Advisor, M-F 8am - 5pm EST, by phone at (888) 446-4226.