Pex A vs Pex B Pipes: What’s Better?


Nowadays, there are various materials you can choose from for your plumbing pipes. Gone are the days when plumbers only needed to work with lead pipes! The popularity of PEX pipes has become more apparent nowadays since you can find them in any home improvement store.

Yet, did you know that pex pipes aren’t all the same? Notably, you can choose between PEX A and PEX B pipes. In which case, what makes these two PEX pipes so different?

Learn their differences to understand which one would be the best for you!

What Are PEX Pipes?

Before you understand the difference between PEX A and B pipes, it’s good to know what PEX pipes are generally. Known as cross-linked polyethylene (PEX), it’s a flexible plastic with various utilities. You can use PEX pipes in building services, pipework systems, hydronic radiant heating and cooling systems, domestic water piping, and insulation for high tension electrical cables.

A PEX A Pipe

Known as the Engel method, PEX A pipes are made by introducing peroxides (a form of oxygen) to the HDPE before forming it. This addition is imperative since it enables more bonding at an atomic level. As a result, PEX A pipes have the highest degree of cross-linking.

A PEX B Pipe

In contrast, PEX B pipes are formed using the saline or moisture cure method. Alternatively known as steam or moisture cross-linking, the process of PEX B pipes is made after the HDPE is extruded into the tube. Once gone through steam, the presence of a silane catalyst encourages the polymers to form cross-links.

How Do They Measure Up?

When comparing PEX A and B pipes, there are certain criteria to be considered to distinguish their pros and cons. See how they stack up against one another to see which pipe type is the best!

In Terms of Flexibility

Interestingly enough, despite PEX A and B pipes coming from the same material, their level of flexibility differs vastly. Since PEX B isn’t expandable like PEX B, its flexibility is greatly limited. PEX A is repaired easily with a heating gun when pipe kinks occur since it will help it expand back to its original shape. Meanwhile, PEX B wouldn’t be repairable, and you would need to cut it out and then start over.

Regarding the Overall Cost

PEX A and B pipes can vary in price depending on how much you need and installation and labour costs. However, when you compare the two PEX pipes, PEX B would be less expensive. The reason is that PEX B’s material is made from cheaper material, and the tool needed for it to be installed costs $150. Meanwhile, PEX A pipes are pricier, with the tool required for it costing $250.

The Ease of Flow

These PEX pipes differ significantly based on their fitting style and how it effectively works regarding flow restriction. With Pex A, they use an expansion tool to enlarge the pipe and sleeve to allow them to slide in the fitting. It’s expandable due to the material’s memory, which shrinks back to its normal size while tightening snugly around the fitting. As a result, there is no risk of flow restriction because it fits the same diameter as the pipe. It’s what makes them ideal for tight places.

Meanwhile, it’s easier and faster to fit since it doesn’t require an expansion tool. Instead, after inserting the fitting into the pipe, it’s fastened securely with a copper sleeve using a simple crimp tool. However, PEX B’s smaller size downsizes the pipe’s diameter at the joint. Consequently, it causes resistance to flow and a decreased volume of water to the fixtures in your home.

Level of Environmental Adaptability

Before finding the ideal one, you need to consider how one of these PEX pipes handles certain environmental conditions. It will take longer for PEX A pipes to shrink to their original size in colder environments. But for PEX B pipes, they’re good under cold or hot weather when fitting them.

Beyond how they respond to fitting in certain conditions, they do handle colder weather in general quite differently. In cold weather that can cause pipes to burst, PEX A is better for resisting pipe bursts since it’s a more malleable material, while PEX B is more rigid, which won’t be as effective.

Despite PEX A and B’s similar makeup, what these two pipes can do is quite different. In essence, it seems PEX A is the best in comparison if you’re looking for a reliable and versatile pipe.