CrossLinked PolyEthylene - PEX

PVC fittings - brass fittings - copper fittings
fittings for repairing PEX pipe - CPVC fittings and information page

There are many reasons for this: some of which may not seem "rational." Also, some people have viewed our attitude as "paranoid" and we understand this.

Our Founder has seen and experienced what happened with polybutylene, (Shell Oil, the resin manufacturer pulled out of the U.S. market mainly due to litigation) and we simply wish to wait and see with PEX whether it will stand the test of time with potable water usage.

One of the main things that bothers us the lack of universality of the pipe and fittings. The continual "improvements" that keep coming along with PEX.

We understand that PEX has been used in Europe in hydronic - closed systems - conditions for over 35 years (but not with chlorine and open systems).
We have recently read where some brands of the PEX piping cannot pass (very) high concentrations (4 parts per million or more) of chlorine. We understand that most potable water never sees over 2 ppm. Our concern is that of time and chlorine; and we simply wish to stay on the cautious side.

"Better safe than sorry" is our Founder's attitude.

Questions we have asked ourselves about PEX piping:

Are all PEX pipe manufacturers offering the same quality of PEX pipe?

Is all PEX piping the same?

Are all methods of connecting PEX pipe and are all fittings for PEX equal?

Then there is this for us to consider:

There is the PE-Xa (Engel Process PEX with manufacturers Wirsbo and Rehau).

There is the PE-Xb process PEX produced by the silane-method (offered by Vanguard also known as PEX-B).

There is evenPE-Xc (irradiation-method of PEX also known as PEX-C).

There also is available the sandwiched PEX/Aluminum/PEX pipe.

PEX is cross-linked polyethylene and it is not ordinary polyethylene pipe.

PE stands for polyethylene and X for cross-linking.

The material's chemical abbreviation is PE-X.

There is PEX specifically made for potable (drinking) water.

There is PEX made for under floor piping and there is PEX specifically made for radiation type heating.

We realize that not all PEX pipe is the same and that makes it very difficult for us to "know" what is "best."

Wirsbo, the quality-oriented manufacturer of AquaPEX (r) - wrote (Product Catalog, dated March 1, 1998)
"Do not use or store AquaPEX (r) where it will be exposed to direct sunlight for more than 30 days."

In Wirsbo's Installation Handbook (May, 1996) it states that if one is unsure of exposure time to sunlight or uv rays, one should "...submit sample of tubing prior to installation."

Cold weather installations?
"In temperatures below 50 degrees, do not hold the tubing in the expanded position for over two seconds."

Cold water durability?
In their warranty, dated May 1,1995:
".....It is expressly understood, that failure as a result of freezing of water within the pipes, or failure as a result of over exposure to direct sunlight, as defined in the current Wirsbo-AquaPEX Installation Handbook, does not constitute a defect in materials or workmanship, and shall not be covered by this warranty....."

US Brass, in Bulletin no: QT-131 (dated October 17, 1996) wrote to their customers:
"Field tests have confirmed that QestPEX (tm) material should not be stored in direct or indirect sunlight.
Failure to adhere to these instructions, as stated in our instructions manual, will void the Qest warranty."

In Reeves Journal, May 1996, page 23, James Hinte, technical engineer for Vanguard plastics (a major, quality-oriented, PEX piping manufacturer) wrote:
".....Cross-linking is a delicate operation-either too much or too little of it can compromise the quality of the finished product....."
Because of the variety of materials used in the PEX manufacturing processes, long term performance is not guaranteed in each case. Users should be careful to consider only pipes which have been tested and shown to meet the requirements of hot water pressure applications."

Since we want our customers to have total satisfaction with everything that they ("you" hopefully) buy from us, we are still, after a number of years, in the process of trying to make up our minds whether to sell PEX or not.

We hope that you will share ANY information, both positive and negative about PEX with us.

We received the following letter from Vanguard Piping Systems Inc. in 1999:
(and we have received written permission to quote the letter, word for word)

"I appreciate you notifying your customers that PEX should not be exposed to DIRECT sunlight, however, indirect light will not harm PEX products which are manufactured to ASTM standards and NSF listed. You also list concerns about PEX installation in cold weather and for cold water. The only approved standard for joining PEX is the metallic insert with metallic crimp ring system (ASTM F1807) which is used by more PEX tubing and fittings manufacturers than any other system. Using this joining method, cold installation and cold water durability are not an issue for the installer...period.

The Wirsbo installation, as you stated, is effected by temperature. Their method is not an approved standard for PEX, at this time, and should not be seen as an issue for our industry as a whole.

The PEX market has grown in three years from nothing to over 12% of the residential plumbing market. Vanguard alone has sold literally millions of feet of PEX tubing into the US market. Europe has been using PEX tubing in plumbing for more than 25 years. Currently PEX and PEX composite pipe (PEX-AL-PEX) is the market leader for residential plumbing tubing in most European markets. It is a proven performer and not unlike any other material you purchase, you simply need to find a manufacturer you believe in and who provides the quality and service you require of the product."
Marisa Morales - Sr. Marketing Manager - Vanguard Piping Systems Inc. - April 8, 1999

We received the following letter from Uponor Wirsbo in 2002:
(and we have received written permission to quote the letter, word for word)

"Wirsbo is the world leader in PEX tubing with billions of feet in service for hundreds of thousands of jobs worldwide. Wirsbo PEX tubing is not only the most installed, most field-proven PEX tubing in the world, it is also the most extensively laboratory tested PEX tubing. Over the past 30 years, Wirsbo PEX tubing has been subjected to a comprehensive array of tests that simulate the most extreme operating conditions, including high temperatures, pressures, and high levels of chlorine in open systems.

The information on PEX fitting systems posted on this site is outdated and inaccurate. Wirsbo fittings meet ASTM standard F1960. In addition, successful cold weather connections are done with Wirsbo fittings every day in North America's coldest climates including Minnesota, Wisconsin and Canada. Thousands of trained Wirsbo installers from across the country are proficient at making successful connections using the Wirsbo ProPEXÒ fitting.

In addition to the many national model code approvals carried by Wirsbo PEX, our tubing also meets the requirement for resistance to chlorinated water that is now being incorporated into ASTM F876. The newly revised standard stipulates that all PEX tubing for potable water listed to F876 must pass a minimum 50 year extrapolated "time-to-failure" test for exposure to hot, chlorinated water when tested in accordance with the chlorine test methods described in ASTM F2023.

Wirsbo is a strong supporter of the trade, and as a result, we choose to sell our products to plumbing and heating wholesalers only. Together with our trade customers, we are proud of the proven, reliable performance that Wirsbo systems have demonstrated in actual field installations and laboratory testing over the last three decades. Wirsbo's considerable experience provides a significant measure of confidence to those who have come to depend on Wirsbo quality."
Cindy Albrecht - Uponor Wirsbo - Customer Relations Manager - December 11, 2002

Here is a comment from a plumber who wrote to us (We are not saying that we agree with him. We are only sharing what he wrote to us. We have received his written permission to show you his letter):
"I have been using Wirsbo Pex and have never had a problem with it. I am a professional plumber from Virginia. Their fittings are twice the weight and thickness of Quest. Wirsbo was designed from the ground up as a plumbing system. Quests was designed around the crimp tool they had on the market for their poly pipe. There have also been pressure problems with the quest as it has a smaller diameter then the Wirsbo. I would heartily recommend the Wirsbo Pex with a modified manifold system. I have had no complaints from customers when this was installed.
Thank you,
signed: Jeffrey"
"You may quote me.
Jeffrey Vanhoozer Stuart, Virginia Plumbing for 19 years."
"The Wirsbo system with their modified manifold or home run as they call it makes for one of the finest piping systems I have ever installed. Every customer just loves it when I replace their old system whether hard plastic, copper or galvanized piping."

As we understand it, there are basically three ways to manufacturer PEX.

The Engel process (Wirsbo is one mfr that uses this method), where the cross linking happens "hot" (in its amorphic state above the crystalline melting point) since the polyethylene, anti-oxidants, and the cross linking initiator (peroxide) are extruded under pressure while in a molten state.

The Silane method (Qest is one mfr that uses this method), where a vinyl silane agent is added to the resin/polymer base prior to the extrusion process, thus forming a grafted copolymer.

The Radiation method, which involves bombarding previously extruded

PE tubing with Gamma/Beta electrons while sealed in a vacuum chamber.

"PEX - what is the bottom line for us (today)?"

Which is the "best" method?

We haven't a clue and, at this point, we (still) do not wish to decide.

We do NOT offer any type/brand of PEX at this time.

Will we ever?

Only time will tell!

We simply wish to stay being "conservative" when offering products.

We would rather lose profits/sales than to sell a product that we don't totally believe in and trust yet.

Yes, PEX might be a great product and we might "kick" ourselves in the future.

We offer many thoughts (quotes) to ponder, such as:
"What we call happiness in the strictest sense comes from the (preferably sudden) satisfaction of needs which have been dammed up to a high degree." - Sigmund Freud