CPVC vs. PVC

What is the difference between PVC and CPVC?

PVC is the name of pipe that is widely used for plumbing material in the construction industry. It is an acronym for Polyvinyl Chloride and is used all over the world. It is not as expensive as GI pipe and is more flexible and this makes it easier to assemble. There is also a newer polymer that is starting to move up in its use in the industry and under certain circumstances it is a better product than PVC. This is CPVC, which stands for Chlorinated Polyvinyl Chloride. It is important to know how they are different so that you will be able to know which one is best to use.

What is PVC?

The inexpensive price of PVC is one of the reasons that it is so widely used in plumbing projects all over the world. It is flexible and this makes it possible to mold it into different shapes to make the various curves and bends often needed to reach the plumbing fixtures. The addition of plasticizers will make the PVC softer. It does not react very well with acids and bases and for this reason it is best used for drainage.

What is CPVC?

CPVC is PVC pipe that has been put through a chlorination process. Thermal or UV energy is used in free radical chlorination, which is a chemical reaction. This energy transforms chlorine gas into free radical chlorine. This reacts with the PVC by replacing some of the hydrogen in the material. It still retains most of the properties of PVC, but the chlorination process makes the pipe material fire retardant. It is, therefore, well suited for use in areas where there are high temperatures – over 220 degrees F. This process also makes it resistant to corrosion, which is something that PVC is not.

The interior surface of CPVC is smoother than PVC. This allows it to transport liquids over longer distances without losing pressure, and encountering problems with scaling or pitting.  It can be used for carrying hot and cold water and for this reason it is the preferred material for installing liquid heating.

There are times when it is better to use PVC over CPVC. One example of such a situation is when liquid ammonia is being transported from one place to another. However, in all other situations CPVC is the best choice.

Summary

  1. PVC has been widely used for a long time because it is inexpensive, but CPVC is fast becoming a competitor, even though it is more expensive.
  2. PVC is thermoplastic polymer and CPVC is created through the chlorination of PVC.
  3. CPVC is better for the transport of hot and cold liquids.
  4. CPVC has a smoother interior than PVC and is resistant to corrosion.
  5. There is higher tensile strength to CPVC and is more ductile than PVC.

 

  • Sachin

    Hi Kevin – What’s better to use G.I pipes of CPVC?