POLYVINYL CHLORIDE (PVC Pipe)

This is the material you're probably most familiar with, and it serves a number of roles in a household aside from in the plumbing. Most main water lines are made of PVC. It's not as flexible as some other types of plastic, and because it warps at high temperatures (hotter than 140°F) it isn't used for hot water lines or in kitchen applications. This type of plastic water pipe will not corrode and features a low heat conductivity.

CHLORINATED POLYVINYL CHLORIDE (CPVC Pipe)

This is PVC piping that's gone through chlorination (treatment with chlorine). CPVC is more durable at higher temperatures and pressures than PVC and is common in industrial plumbing. For homes, it's great for carrying drinking water and handling the hot water lines for which PVC is unsuited. CPVC is more flexible as well. However, it cracks if it freezes, so CPVC isn't useful for water mains because those pipes must be buried in the ground.

CROSS-LINKED POLYETHYLENE (PEX Pipe)

Plumbers often use PEX in home plumbing systems thanks to its many advantages. This type of plastic water pipe is useful for both hot and cold water applications, and is the favorite pipe found carrying freshwater in kitchens and bathrooms. PEX is very flexible, so it fits into most spaces and is inexpensive and easy to work with. It comes in different colors, making it easy for plumbers to identify hot and cold lines for future work. They do need to have support, however, because of their flexibility.

Except for the three types above, there are other types of pipes with different materials such as PPR Pipe, HDPE Pipe, PPH Pipe, etc.

A professional plumber knows the right types of pipes, whether metal or plastic, to use for water line repairs, replacements, and upgrades. Also, the pipes need Pipe fittings to connect the pipes together and allow you to customize your plumbing to suit your needs. There are lots of different kinds of Plastic Fittings with multiple different purposes, such as the drainage of rainwater. Plastic Fitting can be devided into different types as well, such as PPR Fitting, CPVC Fitting, HDPE Fitting and so on.