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The Expansion of PEX

From beginnings to fittings and every application and connection in betweenPEX

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.


Going from A to B

PEXb built on Engel’s novel PEXa 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, PEXb 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.

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.

PEXa and PEXc also meet these jobsite requirements for these applications. They’re closer than cousins to PEXb. All follow crosslinking methods. All must be tested and third-party certified to meet ASTM standards in North America. However, PEXb boasts performance advantages over other crosslinking methods, such as UV and chlorine resistance, thermo stability, and burst strength.

Expanding the Way of Connecting

PEXb is expanding on its capabilities too when it comes down to the connection. PEXb used to be limited to crimp fittings for installation, while PEXa offered a larger opening for expansion fittings. Through meticulous enhancements, PEXb expanded its way of connecting. PEXb 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 PEXb without worrying about complications during installation or difficulties in cold weather conditions.

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.

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