Can you remember a time when the U.S. didn’t have 50 states? If not, you can’t remember a time before CPVC. Hawaii became the 50th state in 1959, the same year commercial production of CPVC began.
At the time, galvanized iron piping was still the dominant plumbing material used in U.S. homes. With suburbs expanding rapidly, however, corrosion in galvanized piping emerged as a key drawback. While the market had already begun to shift to copper piping as an alternative metallic solution, American innovators were already looking ahead to the future of noncorrosive piping.
It seemed logical that plastics could provide a viable alternative to metallic piping, particularly if it was engineered to be fully compatible with chlorinated American drinking water.
PVC (polyvinyl chloride) was already being used for some piping applications, but lacked the temperature and pressure resistance for use in residential plumbing. Scientists found that enhancing PVC with additional chlorine molecules and other additives created a material that could withstand the heat and pressure and was completely immune to the effects of chlorine. The result was CPVC (chlorinated polyvinyl chloride).
Here’s the story of how CPVC grew from those beginnings to the present where more than 13 billion feet of plumbing pipe have been installed in the United States alone—enough to wrap the circumference of the earth almost 10 times.
Proving the concept
CPVC was first applied to residential plumbing through the National Association of Home Builders Research House program. The goal of this program was to develop performance specifications for new materials and equipment that could improve the quality, or reduce the cost, of American home construction. The use of CPVC in NAHB research homes proved to be one of the program’s lasting successes.
The first NAHB research home built with CPVC plumbing was in 1959 in East Lansing, Mich. By 1963, more NAHB test homes had been built with CPVC in California, Maryland and Ohio.
While we haven’t been able to verify if the piping in the first NAHB home is still in service, the FlowGuard Gold team has connected with the current owner of the second home and confirmed that the original CPVC pipe is still in use more than 60 years after it was installed.
By 1968, it had become clear that CPVC pipes and fittings could meet the demands of residential plumbing and ASTM D-2846 was developed for copper-tube sized CPVC. In 1974, ASTM F441 was developed for iron-pipe sized CPVC.
Code approval came shortly after with acceptance by both the Standard Plumbing Code and the Basic Plumbing Code. When the National Standard Plumbing Code was adopted in 1978 through the merger of SBCCI and BOCA, CPVC was included in the original code. CPVC was added to the Council of American Building Officials 1- and 2-Family Home code in 1981 and the Uniform Plumbing Code in 1982.
The 1980s represented a time of rapid adoption for CPVC. Copper piping had largely displaced galvanized iron, but copper, too, was proving troublesome in aggressive water conditions.
As a result, CPVC grew in popularity based on its track record for reliable performance in any water conditions. By the end of the decade, CPVC had become established across the East Coast of the U.S. and spread to the Midwest and Texas. It was also being used by large apartment developers and in high-rise residential projects, where contractors could use iron-pipe sized CPVC for mains and risers and copper-tube sized CPVC for the rest of the building.
Of course, there was another plastic plumbing material in the market in the 1970s and 80s: polybutylene. This material was unfortunately vulnerable to degradation caused by chlorine and often proved unreliable, resulting in widespread failures.
In the early 1990s, a lawsuit against the manufacturer resulted in the largest class action settlement against a building material in history and drove the material off the market.
Meanwhile, CPVC was being improved. The original material had proved its ability to handle U.S. water conditions, but could be difficult to work with due its rigidity.
A new, more ductile formulation was commercialized in 1991. This formulation not only made CPVC easier to install, but it also improved the material’s cold weather toughness.
The new formulation was branded FlowGuard Gold CPVC. While FlowGuard Gold CPVC was more ductile, it did not sacrifice any of the strength or chlorine immunity of the original material.
Several years later, the first one-step CPVC solvent cement was introduced, eliminating the need for primer and allowing faster installation. These advances came at an opportune time as plumbers working under the polybutylene settlement turned to CPVC to repipe affected homes and became converts to the material.
Water compatibility issues with other materials continued to open new markets for CPVC.
For example, in the early 2000s Florida was experiencing a high rate of plumbing failures and the state changed its code to require use of plumbing materials compatible with local water conditions. This resulted in a dramatic shift to CPVC as it was the only material that could claim compatibility with all water conditions.
The FlowGuard Gold CPVC team even developed a succinct way to tell its story to code officials across the state: “If your water is safe to drink, it’s safe for our pipes.”
With any new building material, lessons are learned and best practices are developed as more experience is gained. Because CPVC doesn’t have water compatibility issues, virtually all failures can be traced back to installation errors. As a result, there has been a strong focus on minimizing risks in these areas.
One example is the progress that has been made on combatting dry fits.
One of the lessons learned early in the history of CPVC was that the tight fit between the pipe and fittings could enable a CPVC plumbing system to withstand initial pressure tests even if some fittings had not been properly solvent welded, resulting in failures months or years later.
Since dry fitting increases the likelihood of this installation error, CPVC installation processes were developed that explicitly recommend against this practice.
The risk associated with dry fits hadn’t been helped by the fact that plumbing code required CPVC one-step solvent cement to be yellow, which is difficult to see against the tan CPVC pipe under poor lighting.
To address this challenge, solvent cement with UV indicators was introduced, enabling easier detection of the solvent cement using UV light. More recently, a new high-contrast green cement has been introduced and approved by major code bodies. This new cement will make it much easier to see and avoid dry fit fittings in standard jobsite quality control.
Chemical compatibility issues are a risk to all plumbing systems, and it can take years of application experience to identify the chemicals that are incompatible with a particular system.
Nearly every plumber knows not to put a steel hanger on a copper pipe, because you’ll get galvanic corrosion; and the industry is just starting to learn about how chlorine incompatibility affects systems like PEX and PPR.
Because of its long history, the chemicals that are incompatible with CPVC have not only been identified, but also documented. In 2002, the FBC System Compatibility Program was introduced, giving plumbers a convenient resource to quickly identify what materials are compatible and incompatible with FlowGuard Gold, BlazeMaster and Corzan CPVC.
Preparing for the future
The water compatibility issues we are seeing with some plumbing materials today aren’t new. They drove the invention and commercialization of CPVC piping back in 1959.
In fact, water conditions are getting more aggressive as municipalities make changes to their treatment processes. Yet water compatibility remains an overlooked issue in plumbing material selection and CPVC continues to be the only residential plumbing system that is impervious to chlorine.
Where other plumbing systems have come and gone, CPVC has stood the test of time for more than 60 years.
Jonathan Simon is the North American residential plumbing manager for Lubrizol Advanced Materials Inc., the parent company for FlowGuard Gold Pipe and Fittings