This process is further simplified by modern electrofusion machines that use a bar code scanner to input the correct welding ...

the grip-style mechanical fittings (Photos 3 and 4) can be used on both copper and CPVC pipe. Don't confuse CPVC pipe with the plastic polybutylene systems that were a problem more than a decade ago.

Plastic drain fittings are usually glued ... assuming you can find one. The post A Guide To Pipe Fittings and How To Use Them ...