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What’s the Difference Between Wirsbo and PEX?

After making the final decision to do an overhaul or new plumbing, we start searching for the best material to use. In most cases we settle for renown brands and at times we go for what fits in our budget. Finally you ask yourself the question; will I go for Pex or Wirsbo? What makes them so different?

Most people ask this question on our pexmania forum and we keep telling them that Wirsbo is Pex!  Simply put, Pex is a “crosslinked polyethylene”  a material that is used for plumbing and heating projects. Wirsbo is a brand name representing one of the many manufacturers of pex available in the market all over the world.

In most cases where a client asks if a pipe is wirsbo or pex, they simply want to know where the pipe is classified in the crosslinked polyethylene system.  We did a thorough review of the different types of pex in this article. However, it’s good to mention that Pex is classified in 4 broad groups namely; pex-a, pex-b, pex-c and pex-d.

The method used to induce the cross linking in the polyethylene chain determines the strength, flexibility and memory of the pipe. This is what gives the pex different groupings. The final product determines the type of connections that will be used with the different pipes and we will highlight this aspects in this article.

Lets start off with Pex-a which is the most flexible pex tubing in the market. There are popular brands that make pex-a including Rehau, Comfortpro and Uponor(Previously Wirsbo). Experts recommend the use of cold expansion fittings(F1960) with pex-a.

Alternatively you can use Uponor/Wirsbo propex fittings and they work perfectly as well. the beauty with pex-a is that you can also use all crimp fittings and the push-fit style to get a perfect connection. There are other connection fittings in the market like F2080 and Rehaus Everloc fittings that are comparticble and work perfectly. You will not lack options with pex-a.

Pex-c is not very popular in the market due to a scarcity in the crosslinking equipment. However, its popularity is growing over the years as it presents zero wastage in the materials used. Surprisingly some pex-c pipes have an equal flexibility with pex-a pipe brands for example the Uponor and Vesipex pipes that give a bend radious of six times the inside diameter of the pipe. Vesipex uses cold expansion fittings just like pex-a while other popular brands like  Roth and Sharkbite(barrier only) use the push style and crimp style fittings.

Pex-b is different from all the other pipes as it has a different molecular structure. Thiss makes it the stiffest pipe. It is however not recommended as it has zero molecular memory. The most popular brands include Watts, Viega and Bow. We only recommend various crimp or push fit style fittings with pex-b.

Pex-d is a new technology that has come in the market also known as pex other. It uses UV light combined with an azobenzene reactant to induce cross-linking. Due to its short time use we can not authoritatively talk of its durability and performance in different environments. It has not been recommended for potable water use too.

We recommend any brand of pex-a or Vesipex  pex-c for cold expansion fittings. This is the most reliable fitting type as proven over the years. The fittings are full flow giving them an equal diameter with the pex tubing. The cold expansion fitting come in different types including  STM F 1960  and ASTM 2080.  There are however other fitting connection choices like ASTM F2159 polymer crimp fittings and the ASTM F2854 push fittings that can be recommended by different pex-a and pex-c manufacturers.

With pex-b, you have limited choices where you can use crimp or push-fit style fittings, stainless press sleeves. Copper crimp rings and stainless clamps.  The crimp fittings restrict flow as they have a smaller inside diameter compared to the pex pipes resulting to a pressure drop in the system.

Experts Tip: Always lookout for the manufacturers coding for compatible fittings inscribed on the pipe. This assures you that you are using the approved fitting system before buying the products.


With the outline in this article, you are now best placed to answer any question that will come your way.  You now know that Wirsbo is Pex!