DIN 16836 PEX pipe has become a standard material in modern plumbing, offering a versatile, cost-effective, and durable solution for both residential and commercial water systems. However, not all PEX pipes are the same. There are different types of PEX pipes, with PEX-A and PEX-B being the two most commonly used. Understanding the differences between these two types of PEX is crucial for selecting the right material for your plumbing project. In this article, we'll explore the key differences between PEX-A and PEX-B, helping you make an informed decision about which type of PEX pipe to use in your home or business.
What is DIN 16836 PEX Pipe?
Before diving into the differences between PEX-A and PEX-B, it's important to understand what PEX pipe is. PEX, or cross-linked polyethylene, is a type of plastic pipe that has undergone a chemical process to improve its strength and flexibility. This cross-linking process makes PEX pipes more durable, resistant to scaling and corrosion, and able to withstand higher temperatures and pressures compared to regular polyethylene pipes.
PEX pipes are widely used in water supply systems, radiant floor heating, and even repiping projects, owing to their flexibility, ease of installation, and ability to expand without cracking in freezing conditions.
PEX A vs PEX B: The Manufacturing Process
The main difference between PEX-A and PEX-B lies in how they are manufactured. The manufacturing process affects their flexibility, strength, and overall performance. Let's look at these processes more closely.
1. PEX-A: The Engel Method
PEX-A is made using the Engel method, which involves cross-linking the polyethylene molecules using peroxide during the extrusion process. This method creates a more highly cross-linked polymer structure, which improves the pipe's flexibility and durability.
Pros of the Engel Method:
High flexibility: PEX-A is the most flexible of all types of PEX. This makes it easier to install in tight spaces and allows the pipe to be coiled, reducing the need for fittings and joints.
Resistant to kinking: The highly flexible nature of PEX-A makes it less prone to kinking, a common issue with more rigid types of PEX pipe.
Improved resistance to freeze damage: PEX-A can expand when frozen, which helps prevent pipe bursts in freezing conditions.
2. PEX-B: The Silane Method
PEX-B, on the other hand, is made using the silane method, which involves grafting silane (a chemical compound) onto the polyethylene material and then cross-linking the polymer through a water bath. This method results in a different molecular structure compared to PEX-A.
Pros of the Silane Method:
More rigid: PEX-B is less flexible than PEX-A, making it easier to handle for certain applications but more difficult to bend or install in tight spaces.
Lower cost: PEX-B is typically less expensive to manufacture than PEX-A, making it a more budget-friendly option for homeowners and contractors.
Stronger resistance to chlorine: PEX-B is generally more resistant to chlorine degradation, making it suitable for areas with higher chlorine levels in the water.
Key Differences Between PEX-A and PEX-B
Now that we understand the manufacturing processes, let's explore the key differences between PEX-A and PEX-B in terms of their physical properties, performance, and installation characteristics.
1. Flexibility and Bend Radius
PEX-A is the most flexible of the two types, which makes it ideal for applications where tight bends or coiling are needed. Its flexibility allows it to be installed in places where other types of pipe might require multiple fittings or a more complicated setup.
PEX-B, while still flexible compared to rigid materials like copper or PVC, is less so than PEX-A. It doesn't have the same bend radius, meaning that when you need to make sharp turns, you may need to use more fittings. This can increase both installation time and costs.
Key takeaway: If you need flexibility for tight spaces or want to reduce the number of fittings, PEX-A is the better choice.
2. Resistance to Kinking
PEX-A is highly resistant to kinking, which is one of its main advantages. Kinking occurs when the pipe is bent too sharply, and the material loses its structural integrity, causing water to stop flowing or even creating leaks. PEX-A is designed to maintain its shape even when bent sharply, reducing the chances of kinks during installation.
PEX-B is less resistant to kinking than PEX-A. If you over-bend PEX-B, it can create permanent bends that can lead to leaks or weak spots in the pipe. However, it still performs well under typical installation conditions, where sharp bends are avoided.
Key takeaway: For easier handling and a reduced risk of kinking, PEX-A is the preferred option.
3. Durability and Freeze Resistance
Both PEX-A and PEX-B are highly durable and resistant to freezing. However, PEX-A has a slight edge because it can expand up to three times its normal size before cracking, which makes it more resilient in areas where freezing temperatures are a concern.
PEX-B, while still resistant to freeze damage, doesn't have the same ability to expand. If water freezes inside PEX-B pipes, there is a slightly higher risk of the pipe cracking or bursting compared to PEX-A.
Key takeaway: PEX-A offers superior freeze resistance and durability, making it ideal for colder climates.
4. Cost
PEX-B is generally less expensive than PEX-A, making it a cost-effective option for a residential plumbing system. The manufacturing process for PEX-B is less complex, which contributes to its lower cost.
PEX-A, while offering superior flexibility and freeze resistance, comes at a higher price due to the more advanced manufacturing process.
Key takeaway: If budget is a major factor, PEX-B offers a more affordable alternative, though it comes with some trade-offs in flexibility and durability.
5. Water Quality and Chlorine Resistance
PEX-B tends to have better resistance to chlorine and other chemical degradation compared to PEX-A. This makes it more suitable for areas where the water supply contains high levels of chlorine or other chemicals that may degrade the pipe material over time.
PEX-A is still resistant to chlorine, but over long periods, it may degrade slightly faster than PEX-B under extreme conditions.
Key takeaway: If you are in an area with high chlorine levels in the water supply, PEX-B may be the better choice for longevity.
Which One Should You Choose?
Both PEX-A and PEX-B have their advantages, and the best option for your plumbing system will depend on your specific needs. Here's a quick guide to help you decide:
Choose PEX-A if:
You need maximum flexibility for tight bends and long runs.
You live in a cold climate where freeze resistance is a top priority.
You prefer an easier installation process with fewer fittings and less risk of kinking.
You are willing to invest in a more expensive but high-performing option.
Choose PEX-B if:
You are looking for a more affordable option for a residential plumbing system.
Your system doesn't require the extreme flexibility or freeze resistance offered by PEX-A.
You are working with higher chlorine levels in the water.
Conclusion
Understanding the differences between PEX-A and PEX-B is key to making the right choice for your plumbing project. While PEX-A offers superior flexibility, freeze resistance, and ease of installation, PEX-B is a more budget-friendly option that offers strong chlorine resistance and solid performance for most residential applications.
By carefully considering your needs and the specific demands of your plumbing system, you can make an informed decision and ensure your PEX pipes will perform optimally for years to come.
