Common Types Of Plastic Water Pipes [Choose This!]


Pipes are made from different materials. The most common ones are made from metals and ceramics, and for decades these have been used to make pipes.

Today, in many homes, the pipes used are either made from galvanised steel, clay or cast iron piping. In the 1960s, galvanised steel used to be the most popular piping material, before it got replaced by copper. Today, copper is the most common type of metal used in plumbing systems.

hdpe pipes

Plastic pipes, however, are a popular choice over copper. They are easier to work when compared to copper, especially for sewage applications. Plastic pipes were first used in the 1930s and didn’t become so popular until the 1960s when most plumbers used them.
The materials used to make plastics have evolved over the years. In the past, plastic pipes made from polybutylene were used. However, this material has long been discontinued because it splits and creates leaks. If you have old polybutylene pipes in your house, we advise that you have them replaced as soon as possible with a newer type of plastic pipe.

Apart from polybutylene, there are other different plastics used to manufacture pipes. In this article, we have listed three different types of plastic water pipes that are commonly used by plumbers today:

  • Polyvinyl Chloride (PVC)
  • Chlorinated Polyvinyl Chloride (CPVC)
  • Cross-linked Polyethylene

1. Polyvinyl Chloride (PVC)

This is perhaps the most popularly used plastic material in many homes today and we wouldn’t be surprised if you’re familiar with it. Apart from plumbing, PVCs serve diverse roles in the house. For example, many electrical materials are made from PVCs.

UNDER GROUND PVC PIPES

Most main water lines are made from PVCs. But the downside about PVCs is that they are less flexible compared to other plastic materials used to make pipes. Another disadvantage of PVCs is that they can’t withstand high temperatures (hotter than 140°F) and as such, they are not used for hot water lines or kitchen applications.

But on the good side, plastic pipes, unlike metals, do not corrode and conduct heat less.

What’s The Cheapest PVC Pipe?

Schedule 40 pipe is the most common and cheapest PVC pipe.

More information about PVC schedule pipes will be provided later on in this article.

2. Chlorinated Polyvinyl Chloride (CPVC)

CPVC PIPES

This is PVC that has been treated with chlorine. CPVC pipes are more durable at higher temperatures than PVC. Like PVCs, CPVCs are commonly used at home and even in industries. Because CPVCs can transport water at higher temperatures, they’re widely used at homes to carry drinking and hot water. CPVCs are vulnerable to colder temperatures and tend to crack, making them unsuitable for piping water mains, which are often buried under the ground.

3. Cross-Linked Polyethylene (PEX)

Though PEX sounds like a strange name, it is often used by plumbers in many plumbing applications at home. Thanks to its many advantages, PEX is a top choice for plumbers who want a plastic pipe that can handle both hot and cold water without cracking.

PEX is plumbers’ favourite for carrying freshwater to kitchens and bathrooms. PEX is inexpensive to install, very flexible and so fits into most spaces. Plumbers find PEX easy to work with compared to PVCs. PEX also comes in different colours. This unique feature makes it easy for plumbers to identify the ones meant for hot and cold water. PEX pipes, however, do need support because of their flexibility.

Schedule 40 & Schedule 80 Pipes: Differences

Knowing where a schedule 40 pipe fits or what a schedule 80 pipe is designed for can be very confusing, especially if you have little know about pipes and plumbing. Your water pipes should go exactly where they are most suitable, not where you think they should. Incase you’re confused and can’t tell the difference between a schedule 40 and 80 pipe, below are some pointers to guide you.

Wall Thickness

Schedule 40 PVC and schedule 80 PVC are the most common types of PVC pipe out there. Schedule 40 are often white in colour, while schedule 80 PVCs usually come in grey, but are available in other colours too.
The unique thing about both pipes is their design. Schedule 80 PVCs are designed for thicker walls, which is why they are thicker and stronger and are commonly used in plumbing applications that demand high pressure.

As for schedule 40 PVCs, they are very common and you probably have one in your drainage system. These pipes are white in colour and are widely used for drainage applications, irrigation and cold water systems. You can find the schedule 40 pipes in your local plumbing store.

Though schedule 40 pipes are rigid, they can’t handle higher pressures like the schedule 80 pipes. PVC pipes and fittings have maximum pressures they can handle. You will find their ratings listed in pounds per square inch or PSI. The size of the pipes sometimes determine this pressure. For instance, a 4 inches schedule 80 pipe has maximum pressure of 320 PSI while a schedule 40 PVC of the same size has maximum pressure of 220 PSI.

Inside Diameter

It’s hard to tell the difference between a schedule 40 PVC and a schedule 80 PVC by just looking at them. Both pipes have the same other diameter so that a 1 inch size schedule 40 PVC has the same outer diameter as a 1 inch sized schedule 80 PVC.

The only way to differentiate between them is through their inner diameters. Though their outer diameters may be the same, their inner diameter is always different. Compared to schedule 40 PVCs, schedule 80 pipes have a smaller inner diameter because of their thicker walls. And as a result, water flow is restricted in schedule 80 pipes rather than schedule 40 pipes. This measurement also applies to fittings that are designed for either schedule.

Weight

Given their thicker walls, the schedule 80 pipes weigh more than schedule 40 pipes. Same applies to fittings designed for both schedule.

Price

Because schedule 80 pipes weigh more than schedule 40 pipes, they are pricier to ship and more difficult to handle when installing larger sizes. Moreover, the schedule 80 pipe is pricier than the schedule 40 because they require more PVC material to withstand higher pressures.

Are There Other Types Of PVC Pipe Schedule Pipes?

Schedule 40 and 80 pipes may be the most common types of PVC schedules in the market, but there is the schedule 120 (the least common of the trio). The schedule 120 has a much thinner wall than the schedule 40.

Generally, all these PVC pipes are applied to other materials. For instance you can buy a schedule 40 and 80 pipe, their fittings and combine them.

What Color Is The Schedule 80 Pipe?

Generally, schedule 80 pipe is often gray to distinguish it from the schedule 40 pipe which is white in colour. However, you should always check the manufacturer markings on the pipe to be sure you are buying the right PVC pipe.

What Should I Use: Schedule 40 Or Schedule 80?

If you’re planning to run a high pressure pipe line, the schedule 80 is a good choice for your project. If that’s not the case, then the schedule 40 is enough to handle many pressurised and non-pressurised jobs. Since the schedule 40 pipe is inexpensive, it is a great option for non-plumbing applications.

References:

https://www.pvcfittingsonline.com/resource-center/schedule-40-vs-schedule-80-pvc/

The Different Types of Plastic Pipes Plumbers Use

Joe Taylor

Over 2 decades of remodeling experience, Joe is an expert in home improvement. He is now the Managing Editor of PlumbJoe where he writes guides for homeowners. His hobbies include climbing, running and playing the piano.

Recent Posts