A brief history of the simple invention, now counterfeited, that forever changed the plumbing world

When no-hub couplings, designed to join cast iron pipe and fittings, were first invented in the 1960s, two truths were yet unknown: 1) the coupling would do a better job than anyone dared to imagine, and 2) look- alike counterfeits would one day threaten the health and safety of the American public. Half a century later, domestic coupling manufacturers take great pride in that first truth, and are working overtime to overcome the problems presented by the second.

The history of the no-hub coupling is, in many ways, a metaphor for the American business model. Before couplings, iron pipe and their associated fittings were joined with lead and oakum, a time-honored method that worked very well at sealing joints from leakage. Plumbers learned their trade and accepted this technique as the best possible way to join pipe, until the housing boom of the 50s revealed a basic flaw: joints formed with lead and oakum required too much time and labor to be cost effective. Builders needed a faster way to join pipe as part of their cost-reduction strategy. American pipe producers went to work finding a solution.

Although the alternative had to be less costly than the current joining method, the industry would not stand for a lower-quality joint. The liability involved with producing joints that could leak would make a lesser-quality joint unacceptable to builders and their customers. Anything that could replace lead and oakum had to last at least the life of the building, if not the life of the cast iron pipe. This life would be measured in decades and centuries, not in years. Dozens of idea were floated, and years of testing on these ideas was undertaken. The result was the current no-hub coupling design.

Though simple in concept, the upstart no-hub coupling was a marvel of ingenuity. The new device was comprised of a flexible gasket surrounded by a metal shield held in place and secured by multiple clamping bands. Carefully-designed corrugations in the shield would allow for the joining of pipe and fittings of slightly dissimilar diameters, a condition often found in the field, and overlying clamping bands would hold the shield snugly against the sealing gasket to form the joint. To assure the durability and longevity of the new coupling, several metals and potential gasket materials were tested. Most were rejected as unable to fulfill lifespan requirements, but the developers of the coupling finally settled on two basic materials that would accomplish the goals of providing a safe, secure seal while withstanding corrosion, leakage and other unacceptable breakdowns. Series 300 stainless steel was selected for the shields, sealing bands and screws, and polychloroprene (neoprene) was chosen for the gasket material. It was the selection of these materials that contributed the most to the astounding success of the new coupling.

The design for the new coupling was patented by the Cast Iron Soil Pipe Institute (CISPI), who then set about developing a standard for the new technology. This standard would ensure that licensed manufacturers would produce the product only with the proven materials that would stand up to the rigors of corrosive soils and other challenging environments. The work on this standard would become known as CISPI 310, the standard still in effect today, some 50 years later.

“The Institute wanted to make sure these new couplings would match or exceed the performance of lead and oakum,” said Bill Levan, executive director of CISPI. “Our only goal was performance, but it turned out these new couplings dramatically lowered the cost of joining cast iron, too.”

But the new design was not an instant success in the marketplace. Plumbers were skeptical that anything so simple could actually replace lead and oakum. Many professionals saw the upstart coupling as a quick- fix at best, and the new design was soon being referred to as a “band-aid,” suitable for slapping a temporary repair on a leaking pipe, but hardly the thing to use as a primary joining method. While this attitude persisted in the market for awhile, by the late 60s and early 70s, more and more contractors came to find the coupling a valuable, cost-saving tool. Couplings installed for several years were found to be solid and secure, with plumbers getting few or no callbacks on their joints. As word spread about the reliability of these couplings, attitudes changed. Installers quit calling them band-aids, and engineers routinely specified them as the joining method to use in new construction. Today, no-hub couplings have largely replaced lead and oakum, and are the standard joining method where cast iron no-hub pipe is used. Joints installed during the early years of no-hub couplings are still performing today, with no sign of corrosion of deterioration. No-hub couplings have grown to be the preferred and standard method for connecting hubless pipe and fittings.

When CISPI’s patent expired in the 1980s, the Institute and others attempted to make improvements to the coupling design in order to form a basis for patent renewal. New designs were tried, different materials tested, but try as they might, no manufacturer could improve the coupling enough to convince the government to issue a new patent. The first iteration of the no-hub coupling was too good to be changed.

“It was just not possible to improve our design enough to make a major difference,” said Bill Kenney, president of Anaco, a leading Southern California producer of no-hub couplings. “I guess it’s hard to improve on perfection,” he quipped.

This success, however, has spawned a set of more recent problems. Like Rolex watches and Gucci handbags, standards-compliant no-hub couplings have become the subject of counterfeiting by mostly offshore manufacturers, wishing to capitalize on the success of American innovators. Like counterfeit jewelry and apparel, these couplings are made without regard to standards, and are often comprised of much lower quality metals and elastomers. To further complicate matters, many of these offshore products are listed with American listing agencies, even though simple testing will reveal they do not meet the standard.

“The culture of the offshore manufacturer is just not same,” lamented Michael Lowe, vice president of AB&I Foundry, a national distributor of no-hub couplings. “Where we weigh quality and longevity as the primary drivers of our production processes, too many offshore manufacturers target price as their only objective. Using cheap metals and rubber in their couplings, these guys can get to a lower price, but at what real cost.”

The potential for costly problems was recently brought forward on a hospital project in Prescott, Arizona. The contractor installed non-certified DWV material on the job, but when the engineer took a closer look at the submittal documentation used to justify use of the material, he caught a problem. “[The importer’s] documentation supporting the CISPI standards just didn’t look right,” said Lowell Manalo, Project Manager for Defoe Consulting Engineers in San Diego. Manalo decided to have the material tested by an outside, third-party laboratory. “Eight of the twelve samples we sent for testing failed,” said Manalo, who was now tasked with the unpleasant task of telling the contractor pull out all the installed material and replace it with CISPI-compliant product, an expensive and time-consuming process.

Recent investigations by American producers found that the vast majority of imported no-hub couplings do not meet the standard, and are not capable of lasting the lifetime of the building, much less the life of the cast iron they join. Many in the industry see these couplings as ticking time bombs, prone to failure and leakage within just a few years after installation.

From the contractors’ standpoint, most of whom want to install only compliant couplings, the problem is one of distinguishing between couplings that meet the CISPI 310 standard and those that do not. “If you lay four couplings on the table, two of which are compliant and two of which are not, you can’t tell the difference,” said Kip Wixson, vice president of McWane Plumbing Group of Oakland, California. “The darn things all look alike. Even I can’t tell them apart.”

This identity problem stems from the fact that corrosion-resistant 301 stainless steel looks to the naked eye exactly like lower quality metals. These cheaper metals will not withstand corrosion, and may fail within just a few short months or years. Ditto for the gasket material, where cheap rubber substitutes look the same as neoprene, yet won’t last a fraction of the time required of a durable joint.

To combat this counterfeiting problem, American manufacturers have turned to third-party testing and certification to validate their claims of better quality and standards compliance. “We simply had to do something to separate our products from the look-alike couplings produced overseas,” said Anaco’s Kenney. NSF International, arguably the gold-standard certification agency for plumbing products worldwide, has tested the couplings produced by several domestic manufacturers and certified them to meet the requirements of the CISPI 310 standard. This certification included testing for such factors as materials integrity (e.g. genuine 301 stainless steel and neoprene, shield design, corrugation depth), tensile strength, tear resistance, and accelerated aging. As a result of this testing and certification, compliant couplings now retain the right to display the blue NSF mark. While coupling manufacturers around the world may submit their products to NSF for testing, only American domestic producers have done so to date. Couplings displaying this NSF mark are guaranteed to meet the standard, and the domestic coupling industry is encouraging engineers, contractors and building owners to demand that installed couplings carry the NSF insignia. “To do less is to invite problems,” said Wixson.

The history of the no-hub coupling is a story of success and challenges, but is mainly a story of the ability of simple American ingenuity to change the world. No-hub couplings have lowered the cost of bringing safe sanitary drain, waste and vent systems to the public, with incalculable benefits to society. While the introduction of substandard couplings threatens to diminish the hard-won benefits to be had from no-hub technology, the new ability of plumbing professionals to distinguish what looks, at first glance, to be identical products will largely mitigate the risks to public health that may occur if the challenge by counterfeiters is left unchecked.