Future of plumbing industry seen in hybrid systems

BY TINA MASSEL

Today, hybrids are gaining popularity across a multitude of industries. From automobiles to power generation systems, hybrids are being identified as a smart alternative for today’s generation. That’s because hybrids offer the best of more than one technology, allowing the specifier to customize a solution by combining the benefits of two (or more) different options.

The plumbing industry is no exception. With increased frequency, installers are finding benefit to using more than one product for various applications. The result is often a system that is easier to install, more cost effective and highly reliable.

More piping choices

Once dominated by a single or limited number of piping materials (namely copper and galvanized steel), the plumbing industry today is welcoming newer, high-performance technologies and materials. Plastics, in particular, in both the form of chlorinated polyvinyl chloride (CPVC) and cross-linked polyethylene (PEX), have come on strong, primarily as a result of their corrosion resistance, lower cost and fast, reliable installation methods and are gaining market share in numerous residential, commercial and industrial applications.

In the United States, CPVC has a longer proven history than PEX, even though PEX has been effectively used in Europe for many decades. The strength of CPVC in the U.S. is largely based on its proven performance in domestic water distribution systems that are treated with higher chlorine concentrations and subject to stricter disinfection standards than in nearly any other part of the world.

From its corrosion-resistance benefits to its easy, reliable, cost-effective installation method, CPVC piping has proven to be a viable alternative to copper and other metals. As word has spread regarding its ability to deliver a reliable, economical solution, the frequency of all-CPVC installations (including risers, mains and branch lines) has increased tremendously.

Newer designs of bushings and tees make the transition from larger diameter iron pipe size (IPS) CPVC pipe to smaller diameter copper tube size (CTS) CPVC pipe easier than ever before. As a result, the market is seeing a dramatic increase in the number of commercial installations, including high-rise buildings, where CPVC has been specified throughout the entire water distribution system - branch lines, risers and mains.

The benefits of non-metallic piping systems have been well documented. Starting with their improved reliability, which results from resistance to pitting, scaling and corrosion, CPVC represents a proven, cost-effective alternative for today’s budget-conscious contractors and building owners. Not only are material costs for CPVC attractive, especially in light of skyrocketing copper costs, but the labor cost savings over copper can be significant -- as high as 50% -- depending on the size and complexity of the project.

Much of the labor savings is a result of the fast and easy solvent cement joining system, which eliminates the need for soldering. Because of the nature of the solvent cement joint, it has proven, through lab tests and nearly 50 years of successful field performance, to be the strongest part of the system; stronger than either the pipe or fitting alone. In virtually every other type of water distribution system, the joint is viewed as being the most vulnerable part of the system.

An all-CPVC system offers the additional benefit of noise reduction. A test conducted by NSF International documents that certain branded CPVC pipe can be as much as four times quieter than copper pipe of comparable size. The pipe is also lighter in weight and less susceptible to problems with condensation.

Most importantly, this type of non-metallic plumbing system eliminates the risk of potential contamination from copper and other metals leaching into the water. Numerous medical studies have shown a direct correlation between copper ingestion and a number of birth defects, digestive disorders and even Alzheimer’s disease.

Thanks to benefits such as these, CPVC plumbing systems are now installed in more commercial applications than ever before. In recent years, PEX has also increased in popularity, largely because of its flexibility. With many of the same benefits as CPVC (including corrosion resistance, lower material costs than copper, energy efficiency and fast, easy installations), PEX has become a frequently recognized contender for a growing number of residential and commercial water distribution applications. Contractors like its flexibility, which makes it easy to feed through tight spaces with fewer joints. Although this same flexibility is sometimes criticized for lacking a professional, rigid appearance, PEX is quickly becoming a material of choice for projects that must be done in as little time and at as little cost as possible.

The hybrid advantage

A critical limitation of PEX, however, is that it loses its flexibility in larger sizes (typically in diameters of one inch and greater). In addition, the nature of its crimped joints makes it difficult and more labor intensive to join in larger pipe sizes. For this reason, it has not proven practical to install a 100% PEX water distribution system in projects requiring large-diameter pipe, such as hotels, hospitals, dorms or condos that require a main to be run down the corridor before branching off into individual rooms.

Until recently, this limitation has forced installers to utilize a copper riser and main and then transition to PEX piping for the branch lines. Unfortunately, this combination still introduced copper, and all of its cost and corrosion pitfalls, into the system.

Now, thanks to the introduction of newer manifold designs that facilitate the transition of CPVC to PEX pipe, a newer breed of hybrid plumbing system has been born. A combination CPVC/PEX system delivers all of the benefits of a fully non-metallic system - no corrosion, lower costs, faster and easier installations, lighter weight, less noise and no copper contamination. Plus, it offers the added benefit of having fewer joints behind the wall. Despite the long, proven, reliable track record of solvent cemented CPVC joints, there are still some contractors who prefer to avoid having joints behind a wall. The new hybrid CPVC/PEX system offers that advantage.

The hybrid starts with large-diameter CPVC pipe for the risers and mains and transitions to smaller-diameter CPVC pipe for the branch lines. A CPVC manifold allows for the transition to PEX pipe that runs to the individual fixtures. This allows for a solvent cement coupling on one end and a crimped joint on the other. Without the newer CPVC manifold design, this same transition would have required the use of more ports and additional installation time than what is required today.

Limitations and additional considerations

One word of caution with regard to the use of certain PEX piping in a CPVC/PEX hybrid system relates to their use in a recirculation system. Since a recirculation system is designed to keep hot water in the pipe so that it’s immediately accessible at the spigot, it presents additional concerns relative to chlorine degradation. The heat causes the chlorine (naturally present from disinfection technologies used in all U.S. municipal water supplies) to become more aggressive, and the recirculation means that the chlorine is continually refreshed. While recirculated hot water is not a concern for CPVC systems, it does represent additional risks for certain types of PEX piping that do not carry the nsf Cl-R listing.

This is the reason why the industry has established the upgraded nsf P171 protocol to designate those PEX products that meet a higher standard of chlorine protection. Part of the testing requirements established a Cl-R listing for recirculation systems where water is hot 100% of the time. It should be noted that some PEX systems currently on the market today do not meet the higher Cl-R standard, so it is important to check with the manufacturer regarding a product’s ability to withstand prolonged exposure to hot chlorinated water in those applications where a recirculation system is being installed.

While PEX pipe has been successfully used in Europe and other countries for many years, despite the lack of a Cl-R certification, it has not been subjected to the same high levels of chlorine and other disinfectants mandated by the u.s epa. No other country in the world chlorinates its water supplies to the levels required in the United States.

In conclusion

Today’s plumbing professionals continue to seek solutions that are in line with current economic conditions, without sacrificing the quality needed to ensure a long-term, reliable performance. A hybrid system, comprised of large and small-diameter CPVC pipe, along with flexible PEX piping, represents an opportunity for installers to realize the benefits of two leading, proven piping materials. Assuming the chosen pipe meets the specifications dictated by the parameters of the project, because of its unmatched cost and performance benefits, this new breed of system has the potential to dominate the commercial plumbing industry.                   

Tina Massel, an engineer by training, is currently the commercial building market manager for FBC™ Building Solutions, which includes FlowGuard Gold®, BlazeMaster® and Corzan® piping systems. E-mail inquiries can be directed to tina.massel@lubrizol.com. Or visit www.fbcbuildingsolutions.com for more information.