What Is CPVC Pipe? Here’s Everything to Know

Chlorinated polyvinyl chloride (CPVC) pipe is a popular plumbing choice in modern homes. Valued for its durability and wide range of applications, this chlorinated cousin of polyvinyl chloride (PVC) was first produced in the 1970s. It quickly gained popularity due to its ease of installation and ability to withstand high temperatures.

I recently opted for CPVC during a recent home project instead of copper, my traditional choice. CPVC was especially useful in tight spaces where soldering was difficult or dangerous, and it saved on project costs.

Read on to learn about the properties, uses and advantages of CPVC pipe with three licensed plumbers — Mitch Smedley from Smedley Plumbing, Claude Taylor from YouTube’s “How to Plumbing,” and David Carey from Worcester Technical High School.

What Is CPVC Pipe?

CVPC pipe is a hard, thermoplastic plumbing pipe. “CPVC piping is similar to PVC piping but also very different,” Smedley says. CPVC goes through an additional chlorinating process that increases its flexibility and working temperature range.

What Is CPVC Pipe Used For?

CPVC pipe is ideal for water supply lines. Taylor says it’s best “specifically hot water applications”  but it can also be used for drain lines.

CPVC pipe pros and cons

Pros:

• Easy to install: It’s easy to cut and assemble using glue to connect fittings. You get high-quality results without the copper soldering chore. “You do not need a flame, so it is safer,” Carey says.
• Durable: Harsh water won’t harm the material, unlike copper, which will erode from acidic water. “[It] will not rust out,” Carey says. CPVC pipe tubing and fittings are perfect for areas of the country with aggressive water that eats away at copper pipes.
• Heat and pressure-resistant: CPVC is capable of carrying 200-degree water at 100 psi (water in the average home is about 125 degrees at 50 psi).
• Inexpensive: CPVC costs .50 to $1 per sq. ft., making it one of the cheapest plumbing pipe options.

Cons:

• Needs more support: Because of its flexibility (which can be an asset), you’ll need to support it more often than copper or galvanized steel — every 32 to 36 inches.
• More brittle than metal pipes: CPVC is less tough than copper or galvanized steel. Take care not to strike it with a hammer, and be sure to use steel nail plates in wall framing if a nail or screw puncture is a possibility.
• Expands and contracts more than copper tubing: This is especially true in hot water lines. A 10-foot piece of tubing can grow in length by as much as 1/2 in.
• Requires slow-drying adhesive: “It takes eight hours for the glue to dry in some situations,” Carey says.

What’s the Difference Between CPVC and PVC Pipe?

There are several differences between CPVC and PVC pipes.

Applications

“PVC is only allowed to be used in drain, waste and vent plumbing applications,” Smedley says. It is not approved for use as a water supply line, whereas CPVC is primarily used in water delivery applications.

Heat tolerance

PVC starts to melt at 140 degrees Fahrenheit, while CPVC can tolerate hot water up to 200 degrees Fahrenheit.

Sizing

PVC and CPVC have different sizing measurements. “PVC will follow iron pipe sizing (IPS) whereas CPVC will follow Copper Tube Sizing (CTS),” Smedley says.

CVC or CPVC: Which Is Better?

It really depends on the application. “They both are great but for their own purposes,” Smedley says.

PVC is preferred for drain lines, as it is not as sensitive to certain chemicals as CPVC. CPVC is great for plumbing supply lines, especially hot water.

How To Tell if a Pipe Is PVC or CPVC

You can quickly distinguish between the light beige color of CPVC pipe and the bright white of PVC. If you’re unsure, look for the printing on the side of the pipe.

What Other Types of Pipes Are in Use Today?

There are a few other plumbing pipe options available.

PEX

Cross-linked polyethylene (PEX) is a flexible plastic piping system used for cold and hot water supply lines. It is valued for being inexpensive, long-lasting and easy to install. It also requires fewer joints for a lower risk of leaks. However, PEX is not UV resistant and requires more support at fixtures due to its flexibility.

Copper

Copper plumbing pipes are long-lasting metal pipes that can withstand high temperatures. Copper pipes can be used for supply and drain lines.

However, it’s expensive, heavy and requires soldering for installation. “And if a copper water pipe freezes, the pipe will split,” Carey adds.

Polyethylene (PE)

PE is durable yet flexible plastic tubing typically used in cold water applications, such as supply lines, wells and irrigation systems. It is valued for its chemical resistance and ease of installation.

However, it cannot withstand high water temperatures.

Frequently Asked Questions

Can you connect PVC and CPVC pipe?

“Mixing CPVC and PVC is not recommended,” Taylor says, especially with glue. Each material has a corresponding glue that will not work well on the other type.

If you have to join the two, Smedley recommends using adapters. “[Glue] a male adapter on one and a female adapter on the other,” he says. “Then thread them together using Teflon tape or pipe joint compound.”

Which pipe best for plumbing?

Which pipe is better for plumbing really depends on a few factors.

If money is no object, and you value time-tested durability, copper pipe is your best choice. If you’re on a tight budget and don’t want to solder pipes, CPVC is your best option. Carey prefers to use PEX because it doesn’t rust or corrode, and “if PEX freezes, it will just expand and not split.” Weigh the pros and cons of each type to fit your unique situation.

What kind of pipe is the cheapest?

“PEX and CPVC are the cheapest,” Carey says, with CPVC slightly cheaper than PEX.

How long do PVC and CPVC pipes last?

Expect a lifespan of 50 to 70 years. “They each should last a very long time as long as they aren’t damaged from freezing or UV rays,” Smedley says.

About the Experts

• Claude Taylor is a Master Plumber in Texas with over 30 years of residential and commercial experience. He is also the host of “How to Plumbing” on YouTube with over 50K subscribers.
• David Carey is a Master Plumber in Massachusetts with over 30 years of plumbing experience. He is also Department Head of Worcester Technical School‘s plumbing program in Worcester, Massachusetts.
• Mitch Smedley is a Master Plumber and owner of Smedley Plumbing in Kansas City, Missouri. He has 15 years of industry experience and hosts a YouTube channel of plumbing information and how-to’s.