PEX A vs. PEX B

Attribute	PEX A	PEX B
Flexibility	High	Medium
Strength	High	Medium
Resistance to Chemicals	Excellent	Good
Temperature Resistance	High	Medium
Cost	Higher	Lower

Introduction

When it comes to choosing the right type of cross-linked polyethylene (PEX) pipe for your plumbing needs, two popular options are PEX A and PEX B. Both PEX A and PEX B offer excellent durability, flexibility, and resistance to corrosion, making them suitable for a wide range of applications. However, there are some key differences between the two types that may influence your decision. In this article, we will compare the attributes of PEX A and PEX B to help you make an informed choice.

Manufacturing Process

PEX A and PEX B are manufactured using different methods, resulting in variations in their properties. PEX A is produced using the Engel method, which involves cross-linking the polyethylene molecules during the extrusion process. This method creates a more uniform and consistent cross-linking throughout the pipe, resulting in enhanced flexibility and resistance to stress cracking. On the other hand, PEX B is manufactured using the Silane method, where the cross-linking occurs after the extrusion process. This method allows for greater control over the degree of cross-linking, resulting in a slightly stiffer pipe compared to PEX A.

Flexibility

One of the key advantages of PEX pipes is their flexibility, which allows for easy installation in tight spaces and around corners. PEX A is known for its exceptional flexibility, thanks to its uniform cross-linking. This flexibility makes it easier to work with, especially in colder temperatures, as it can withstand more bending without kinking or breaking. PEX B, although slightly less flexible than PEX A, still offers excellent flexibility, making it suitable for most plumbing applications. However, in situations where extreme flexibility is required, such as in radiant heating systems with many bends and turns, PEX A may be the preferred choice.

Resistance to Temperature and Pressure

Both PEX A and PEX B are designed to withstand high temperatures and pressures commonly encountered in plumbing systems. PEX A has a higher resistance to temperature extremes, making it suitable for both hot and cold water applications. It can handle temperatures ranging from -40°F to 200°F (-40°C to 93°C). PEX B, on the other hand, has a slightly lower temperature resistance, with a range of -40°F to 180°F (-40°C to 82°C). When it comes to pressure resistance, both types can handle typical residential plumbing pressures without any issues.

Installation Method

The installation method for PEX A and PEX B differs due to their varying flexibility. PEX A is typically installed using the expansion method, where the pipe is expanded using a specialized tool and then fitted onto fittings. As the pipe contracts, it creates a secure and leak-free connection. This method eliminates the need for additional fittings, reducing the potential for leaks. On the other hand, PEX B is commonly installed using crimp or clamp fittings. These fittings are secured onto the pipe using crimp rings or stainless-steel clamps. While this method is effective, it requires more fittings and may have a slightly higher risk of leaks compared to the expansion method used with PEX A.

Chemical Resistance

Both PEX A and PEX B exhibit excellent resistance to chemicals commonly found in plumbing systems, such as chlorine and various acids. They are also resistant to corrosion, ensuring long-term durability. However, PEX A has a slight advantage in terms of chemical resistance due to its more uniform cross-linking. This enhanced resistance makes PEX A a preferred choice for applications where exposure to aggressive chemicals is a concern, such as in commercial or industrial settings.

Cost

Cost is often a significant factor when choosing between PEX A and PEX B. PEX B is generally more affordable than PEX A, making it a popular choice for residential plumbing projects with budget constraints. The lower cost of PEX B is primarily due to the manufacturing process, which is less complex compared to PEX A. However, it is important to consider the long-term benefits and durability of PEX A, which may outweigh the initial cost difference in certain applications.

Conclusion

PEX A and PEX B are both excellent choices for plumbing applications, offering durability, flexibility, and resistance to corrosion. PEX A stands out for its exceptional flexibility, temperature resistance, and chemical resistance, making it suitable for a wide range of applications. On the other hand, PEX B offers good flexibility, affordability, and is commonly used in residential plumbing projects. Ultimately, the choice between PEX A and PEX B depends on the specific requirements of your project, budget considerations, and personal preferences. Consulting with a plumbing professional can help you make an informed decision and ensure the best outcome for your plumbing needs.