CPVC fittings are made out of chlorine and ethylene. CPVC fittings can be used with either hot or cold water systems, making it a versatile material for most plumbing applications. Unlike other plumbing systems, CPVC uses a chemical glue to bond the fittings together. This makes for a permanent seal that's watertight and highly resistant to corrosion. CPVC fittings are molded using injection technology that creates a fitting with very tight tolerances, for snug connections every time.
Brass is used on high-end faucets and other bathroom fixtures. Brass is among the most long-lasting of materials available for residential plumbing fixtures, as it resists corrosion and is very durable. Brass faucets usually contain brass connection points for plumbing, such as supply lines or drain pipes. These connection points all contain standard pipe threads, which can operate with almost any pipe with the same type of threads. This makes connecting different types of plumbing straightforward in most cases.
CPVC fittings that contain threaded connections are compatible with any brass connection that contains the same types of pipe threads. However, it's critical to lubricate the threads of any CPVC fitting with a layer of plumber's tape prior to installation. Wrap the threads about two times with plumber's tape to lubricate the threads and help ensure a tight connection. A thin layer of liquid pipe dope also will work. It's important not to over-tighten CPVC fittings on brass, as the heavier metal connection will often crack the more delicate CPVC.
Some fittings require special adapters to make the connection. For example, if your brass faucet contains straight copper supply pipes, you must use a CPVC fitting that's pre-molded into a copper fitting. These dual fittings allow you to transition from copper to CPVC, with the copper end soldered and the CPVC end glued in place with CPVC cement. Other alternatives for this type of connection include push-to-fit compression fittings, which don't require soldering or glue to make the transition. Ask an associate at your local hardware store to show you the range of options available for your application.