The Differences Between PEX-A, -B and -C

PEX (cross-linked polyethylene) pipe is a type of flexible plastic tubing used in plumbing systems for the transport of water. It was developed in Europe in 1968 and later introduced to the United States in the mid-’80s. PEX pipes have gained widespread popularity in residential plumbing for the past few decades due to their flexibility, durability, and ease of installation.

Key features of PEX pipes include:

1. Flexibility: PEX pipes are highly flexible, allowing for easy installation in various configurations, including tight spaces and around corners, without the need for additional fittings.

2. Corrosion Resistance: PEX pipes resist corrosion and scale buildup, providing a longer lifespan compared to some traditional metal pipes.

3. Freeze Resistance: PEX has the ability to expand and contract, making it less prone to bursting in freezing temperatures compared to rigid pipes.

4. Cost-Effectiveness: PEX is often more cost-effective than traditional materials like copper, both in terms of material cost and installation.

5. Lightweight: PEX pipes are lightweight, making handling and installation more convenient for plumbing professionals.

PEX pipes come in different types, commonly denoted as PEX-A, PEX-B, and PEX-C, which refer to the manufacturing methods used to cross-link the polyethylene. Each type has its own characteristics, but they all share the advantages of PEX as a versatile and reliable plumbing material.

So what are the Differences between PEX types? The truth is not a whole lot. Again, the main distinction lies in the manufacturing method, which is what assigns an A, B or C to PEX.

The main difference between PEX-A, PEX-B, and PEX-C lies in the manufacturing methods used to cross-link the polyethylene, which is what assigns the A, B, or C designation:

1. PEX-A (Peroxide Method):

1. This method involves using peroxide to initiate the cross-linking process.

2. PEX-A pipes are known for their superior flexibility, making them easier to install, especially in tight spaces.

3. They also have better resistance to chlorine and other chemicals.

2. PEX-B (Silane or Moisture Cure Method):

1. The Silane method utilizes a chemical compound called silane to initiate cross-linking.

2. PEX-B pipes are the most common type in use.

3. They strike a balance between flexibility and stiffness, making them suitable for various applications.

3. PEX-C (Electronic Irradiation or Cold Method):

1. PEX-C is manufactured using the electronic irradiation method.

2. These pipes exhibit good chlorine resistance and are relatively easy to install.

3. They are less flexible than PEX-A but more flexible than PEX-B.

While the manufacturing methods result in some variations in properties such as flexibility, each type must meet the same performance standards, and their sizes, Material Designation Codes, and compatibility with fittings remain similar. The choice between PEX-A, PEX-B, and PEX-C often depends on specific project requirements and installer preferences.