From beginnings to fittings and every application and connection in between
In the mid-1900s, indoor pipes consisted of copper and metal materials. These plumbing solutions became problematic against corrosive environments. Pitting of the pipes put in question the integrity of the water supply and users at risk.
Enter Engel...
Pioneering PEX
German inventor, Thomas Engel, pioneered a new way of piping by crosslinking polyethylene using a peroxide method. This method proved both more cost-effective and long-lasting—the piping held up to heat, it was easier to work with during installation, and more reliable against corrosion over time.
By the 1980s, homes and businesses were using PEX for plumbing projects and radiant floor heating inside their buildings. There are three types still used by contractors: Engel’s or PEXa, the Silane process or PEXb and Electron Beam method or PEXc.
PEX A vs PEX B
PEX A uses larger-diameter expansion-style fittings, requiring an expansion tool to enlarge the pipe and sleeve. Its unique expandable nature, driven by memory features, ensures a snug fit when it contracts back to its original size around the fitting.
PEX A offers exceptional flexibility, enabling tighter radial bends and easy kink repair with a heat gun. The material can expand back to its original shape.
Pros: PEX A ensures unrestricted flow with matching pipe and fitting diameters, making it ergonomic for tight spaces and quick connections in challenging areas like joist bays.
Con: In cold climates expansion fittings may delay their return to the original size. Solution? Use a heat gun to speed up the contraction.
PEX B
PEX B utilizes insert-style fittings by inserting them into the pipe and securing them with a copper sleeve using a crimp tool.
PEX B, although made of similar material as PEX A, has limited flexibility. In case of kinks, repairs are impossible, necessitating the replacement of the affected section.
Pros: PEX B offers a tool-free, consistent joining method that's quick and easy in any weather.
Con: PEX B fittings reduce flow and water volume at the joint due to their smaller diameter and may result in leaks if crimped incorrectly.
PEX b built on Engel’s novel PEX a by crosslinking through a physical, chemical process, essentially fortifying the pipe’s high temperature threshold, resistance to UV rays and harsh or acidic elements, and overall toughness. Even with the robust reinforcement, PEX b proved to be just as flexible on the job. Today, this is by far the most widely used solution for all the above. We’re talking like well over half of all plumbing projects.
In frigid climates, freezing pipes and potential bursts are worrisome. PEX A offers higher burst resistance, capable of withstanding up to 500 PSI in extreme cold, while PEX B, being more rigid, is less resilient.
The manufacturing enhancement opened the door (literally) to more outside applications for both residential and commercial spaces, such as irrigation systems, radiant heating on sidewalks and driveways, and outdoor water systems.
PEX a and PEX c also meet these jobsite requirements for these applications. They’re closer than cousins to PEX b. All follow crosslinking methods. All must be tested and third-party certified to meet ASTM standards in North America. However, PEX b boasts performance advantages over other crosslinking methods, such as UV and chlorine resistance, thermo stability, and burst strength.
Expanding the Way of Connecting
PEX b is expanding on its capabilities too when it comes down to the connection. PEX b used to be limited to crimp fittings for installation, while PEX a offered a larger opening for expansion fittings. Through meticulous enhancements, PEX b expanded its way of connecting. PEX b pipes are now fully certified for use with both ASTM F1807/F2159 crimp and ASTM F1960 expansion fittings and accessories.
What does this mean? Well, expansion PEX can offer a path of leak resistance if used with a certified expansion tool. Certified tool heads feature interlocking teeth and unique nose design, specifically for PEXb. This industry innovations allows homeowners and building owners to upgrade to the strength of PEX b without worrying about complications during installation or difficulties in cold weather conditions.
PEX Expansion Tool
The Zurn PEX F1960 Expansion Head, compatible with DEWALT® DCE400 and Milwaukee® M12™ ProPEX® Tools, streamlines PEX system assembly, ensuring leak-free connections. Designed for Zurn Non-Barrier PEX pipe, it creates secure connections with ASTM F1960 fittings.
Choosing PEX for Your Project
No matter, which option you choose—a, b, or c—PEX surpasses copper piping for reliability across all indoor applications. You’re guaranteed to save project costs and labor and extend the lifespan of your system with fewer maintenance requests or problems down the road with your water source. However, if you’re looking to get more creative outdoors or want more jobsite flexibility, you may want to consider PEXb.
It’s hard to say what’s next for PEX. But seeing as it’s the most versatile solution in the plumbing world, we can only expect another advancement or discovered use in time.
FAQs
PEX a is made using the peroxide, or Engel, method. PEX b is formed using silane, or moisture cure, method. This is the most common PEX pipe type out there. PEX c is created using the electronic irradiation, or cold, method of cross-linking.
Can PEX b be used with expansion fittings? ›
PEX b used to be limited to crimp fittings for installation, while PEX a offered a larger opening for expansion fittings. Through meticulous enhancements, PEX b expanded its way of connecting. PEX b pipes are now fully certified for use with both ASTM F1807/F2159 crimp and ASTM F1960 expansion fittings and accessories.
Which PEX for expansion fittings? ›
PEX A uses an expansion-style fitting. These fittings are much larger in diameter the PEX B fittings, and require an expansion tool. Using the expansion tool, you enlarge the pipe and sleeve in order slide in the fitting.
What is PEX c good for? ›
PEX-C. PEX-c has less coil memory than PEX-b due to its manufacturing process. It's commonly used for supply lines from the supply stop to the fixture but is the least commonly used product in behind the wall water distribution systems.
How much do PEX b fittings reduce flow? ›
At a rate of 8 feet per second, the CPVC fitting will cause less than 1% restriction in flow while PEX fittings create a 23% to 54% reduction in flow, depending on the fitting used.
What is the lawsuit against Uponor? ›
Uponor Inc. was hit with a product liability class action Tuesday in Tennessee Middle District Court over the company's manufacture of polyethylene tubing used in plumbing systems.
Can I go from PEX A to PEX B? ›
It'll work in the real world, but the manufacturer does not recognize this as a transition. So if you're a contractor transitioning from PEX-A to PEX-B, you should ask the manufacturer about how they want you to make this transition Get it in writing, so it doesn't void your warranty.
Are all PEX expansion fittings the same? ›
If you're a plumbing and heating contractor who has been told by your distributor that all PEX F1960 expansion fittings are the same, be forewarned. That is simply not true. And the differences in low-quality F1960 fittings can come with considerable risk to your installations and your reputation.
What is the best PEX connection method? ›
Again, our #1 recommendation is to always use PEX Crimp fittings with Copper Crimp Rings.
Is it better to crimp or expand PEX? ›
Pex clamp connections are also secure but not reliable as crimp connections. However, Pex clamp connections made of stainless steel rings are more durable. You cannot use a crimping tool in confined spaces. Also, using the tool requires much pressure to make secure connections.
PEX cannot be used in areas with high heat, such as water heater connecting lines or near recessed lighting. Most professional plumbing experts advise sticking to the same manufacturer for tubing and fittings, which might not always be the most cost-efficient.
Can you expand PEX Type A? ›
PEX A is: More flexible, making it expandable and suited for fastening by cold expansion. Resistant to kinking that will make a pipe unusable. Installed with an expansion-style fitting.
Should I use PEX A or PEX B? ›
While PEX-b claims to be approved for use with expansion fittings, the pipe does not have the same elasticity as PEX-a and can therefore experience microcracks when expanding. Hence, PEX-b typically works best with smaller-diameter insert-style fittings that are secured by a crimp tool.
Is PEX C safe for drinking water? ›
Yes. NSF/ANSI/CAN 61, a plumbing standard that evaluates the health effects of potable water system components, tests for BPA levels in plastic piping and confirms that it isn't detected in our PEX pipe. PEX is made of cross-linked HDPE (high density polyethylene).
Is PEX a better than PEX C? ›
PEX-A is the most flexible of all PEX pipe types, it has little or no coil memory and gives installer the ability to repair kinks with a heat gun. It has been in use for over 50 years which is longer than other types and a lower bending radius in PEX-A (6 times the OD vs. 8 times the OD for PEX-B & C) is helpful.
Can you use SharkBite on PEX A? ›
Installing SharkBite PEX-A Pipe in Concrete
entering or exiting the concrete slab. A larger diameter piece of SharkBite PEX also works well in this application. continuous length of SharkBite PEX within the slab and be sure to check for leaks before pouring concrete.
What is the best type of PEX to use? ›
PEX-A is the most flexible and is suitable for use in all home water-supply plumbing needs. It is the most resistant to cracking due to freezing, as it can expand the most. PEX-A is more expensive than B or C, and has no major benefit over PEX-B besides its greater flexibility.
Is PEX A or B better for underground? ›
All types of PEX piping could be installed underground, nonetheless, it's better for you to research which type will last longer in this condition. As a general rule, PEX B can withstand freezing temperatures for a longer time than PEX A due to its high bursting pressure. However, it is less flexible than PEX A.
Is PEX A and B the same? ›
The wall thickness of PEX A systems is normally greater than PEX B because it has a lower burst strength and hence requires the greater thickness to cope with the same operating pressures. Yes PEX A is more flexible than PEX B but both types of PEX have the same minimum bending radius.
