What is Pex?

PEX tubing has been installed in high rise buildings across the country. In cases where failure has occurred in high rise structures there are millions of dollars in damages.

What is Pex?

PEX was developed in the 1960s in Europe and introduced to the United States in the late 1980s. PEX tubing is used in radiant heating systems and PEX plumbing systems. PEX tubing became the prevalent substitute to copper pipe in the 1990s due to its lower installation and material costs. PEX is a generic term for a plastic pipe made of cross-linked HDPE (high density polyethylene). Cross-linking is a chemical reaction that occurs between polyethylene chains. Cross-linking causes the polyethylene to become stronger and resistant to cold temperature brittleness while retaining flexibility. Through one of several processes, links between polyethylene molecules are formed to create channels (thus the tenure “cross-linked”). There are currently three methods for producing PEX tubing, the “Engle” or “Peroxide” (PEX-A) method, the “Silane” (PEX-B) method, and the “E-beam” or “Radiation” (PEX-C) method. Alphabetical order is irrelevant and not related to any type of rating system in production. The degree of cross-linking required by standard is based on the material and methods used to produce PEX tubing. It is has no relation to quality within the pipe.

Pex Vulnerability

Information is optimistic about PEX regarding the changes in production, its durability, ease of installation and inexpensive cost. PEX seems to be the new wonder product in America. We feel differently about PEX steadiness due to difference in production methods; the performance standards in which PEX is released market-ready are minimal at best. Our concern with PEX is the amount of chlorine (City water) the plumbing system can be continuously exposed to before failing, especially in hydronic systems. Chlorine resistance becomes a major focal point to our view of PEX. When PEX is used for radiant heating or in a recirculation system, warm water circulates throughout the loop of the system. As chlorinated water continues to constantly circulate the system, chlorine can break down the interior of the pipe.
To help alleviate potential concerns associated with chlorine resistance the National Science Foundation (NSF) International developed a test protocol (NSF P171 CI-R) to evaluate the chlorine resistance of PEX products. This test evaluates PEX pipe at high temperature conditions. The PEX is exposed to these conditions until failure occurs; this determines a relative estimate of life expectancy. NSF CI-R protocol allows for 80 years of service at 100 percent hot water usage. This NSF CI protocol is a voluntary program for PEX pipe manufactures.
Two of the three production methods have failed and continue to fail the chlorine recirculation test (NSF P171 CI-R) developed by NSF. As of January 1, 2007 neither PEX-A nor PEX-C methods can or have passed this test.
To address this same issue, the American Standard for Testing and Materials (ASTM) International developed a chlorine methodology test. This standard allows for 50 years of service at 25 percent hot water usage. All PEX must pass this minimum standard to be commercially available when relating to chlorine resistance. ASTM writes standards and conducts educational training seminars. ASTM does not conduct testing, listing, certifying, or enforcement of its standards.

Pex Failures Class Actions

PEX class actions have been filed: Uponor, Inc and Radiant Technology, Inc (a related company), Zurn Pex, Inc and Zurn Industries, Inc, Rehau PEX fittings, and IPEX class action regarding the alleged defectiveness of Kitec.

Delta’s Belief

PEX tubing has been installed in high rise buildings across the country. In cases where failure has occurred in high rise structures there are millions of dollars in damages. For example, if fittings leak or the pipe composition fails on the top story of a high rise building water flow will follow gravity. As we have seen with copious Kitec (a type of PEX pipe in which an aluminum pipe is “sandwiched” between inner and outer layers of PEX polyethylene) failures, PEX tubing can ultimately fail. Delta Mechanical has witnessed failures involving fittings used on domestic water systems. The fittings appear to suffer from corrosion cracking and fail from the inside out. PEX failures are developing across the United States (see accompanying map below).

It is our belief that at a future date, class actions may arise regarding PEX plumbing systems. Billions of feet of PEX tubing have been installed worldwide and is continuing to be installed. In all likelihood, the failures will continue, additional fittings and pipe will exhibit the same problems currently under scrutiny and failures will manifest in across the country. PEX products have been subjected to continual “improvements” since the late 1950s. Their “improvements” have not been proven safer than previous ones, so future failure rates remain unknown. PEX has even been under environmental assessment (since 2008) for the leaching of MTBE and benzene (which are highly flammable compounds) into drinking water, due to premature decay and rupture. The flammable material may allow fire to spread rapidly through homes with PEX plumbing. Clients with PEX plumbing have complained of problems with leaks in walls and ceilings due to perceived fitting failures and quite possibly the pipe. Plumbing disasters can take many forms. In addition to damage to floors, walls, ceilings and personal property, there can be mold growth and other health risks to deal with because of a faulty plumbing system. An actual leak is an obvious sign of trouble. However, what can be worse is the knowledge that you may have a potentially defective product that’s known to fail. That equates to an issue that you won’t see, can’t locate and won’t hear. The issue of PEX failures has grown beyond just a plumbing issue. Delta Mechanical supports that building materials should be studied before we allow them to be used in homes; we intend to avert futures disasters such as asbestos insulation and polybutylene pipe. The average price of a repipe for a 2.5 bath home will run $5,600.00 to $6,000.00 if repiped with Flowguard Gold CPVC. This is a cost-effective solution when compared to the tens of thousands of dollars extensive repairs and damage restoration can cost. Call us today for your free estimate over the phone. We will ask you the questions needed to guarantee the final cost of your repipe and stand by it. We are confident that you will not find any other company that warrants final pricing with no additional or hidden charges.


Delta Mechanical is not announcing that all PEX plumbing systems are alleged defective. We believe that the stability of PEX plumbing system pivots on the production method selected by the manufacturer. There is room for a potential defect in certain types PEX plumbing systems. Delta Mechanical is the nation’s leader in defective pipe replacement. Whether you would like verification of your current plumbing system or a free estimate over the phone, Delta Mechanical is here to serve your needs. Our dispatchers are highly trained customer service specialists. We are so confident that you will love our price and our quality; it’s our personal promise. Our team members are polite, courteous and knowledgeable. We guarantee that we will beat any written estimate by at least 5%. We finish your project on time and to your satisfaction. We have the professionalism that stands out among the repipe industry nationwide. We ensure that we will provide you with the most effective solution to your plumbing problem; customized to fit the needs of your home.


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