Plumbing and Mechanical

Greatest Plumbing & Heating Inventions

April 3, 2008
People take for granted devices such as the T&P valve, kitchen disposal, flush toilet and so many of our industry's other useful gadgets that have made lives safer, healthier, more comfortable and convenient.

An early-trades exhibit at the Museum of Science & Industry in Chicago.


The nature of plumbing is such that its most clever innovations usually are obscure to the public eye. People take for granted devices such as the T&P valve, kitchen disposal, flush toilet and so many of our industry’s other useful gadgets that have made their lives safe, healthier, more comfortable and convenient. Even plumbers who work with these mechanisms every day tend to lose sight of the ingenuity that went into them. By spotlighting these great inventions, we hope to instill a greater appreciation for the creativity of our industry’s forefathers.

In compiling this series we tapped the engineering departments and archives of major plumbing manufacturers for guidance. We thank them for their cooperation.

Kohler’s introduction of bathroom sets (bathtub, toilet and lavatory) in matching colors made fixtures much more than functional.

Innovations At Kohler Co.

1911: Kohler Co. introduced the industry’s first one-piece recess bath with an integral apron. Before this time, built-in baths were cast in two separate sections-the tub proper and the apron. The apron and the tub were then either fitted together by the plumber when the tub was installed, or the two pieces were welded together at the factory before the fixture was enameled. The new one-piece tub, void of crevices, joins and seams, was much more sanitary and attractive than the two-piece forerunner.

1926: One of the most advanced products to come out of the 1920s was the Kohler electric sink. It was a combination of a conventional kitchen sink and the electric dishwasher almost as we know it today. The sink was an enameled iron fixture, massive and expensive, half sink and half dishwasher. Invented by Kohler employee Frank Brotz, its only drawback was that it was a generation or two ahead of its time.

1927: Kohler’s introduction of bathroom sets (bathtub, toilet and lavatory) in matching colors made fixtures much more than functional. Now instead of stark and sterile white, consumers could choose spring green, lavender, autumn brown, old ivory or horizon blue. For the first time, there was a concern for the aesthetics when planning a bath. However, beyond aesthetic considerations, the color concept was a revolutionary technological achievement in the plumbing industry of the time. The manufacturing of enameled cast iron fixtures and vitreous china fixtures required vastly different raw materials, processes and techniques, so matching color was difficult.



Al Moen holds more than 75 patents, but his most revolutionary is the one issued in 1942 for the single-handle mixing faucet.

Moen’s Single-Handle Mixing Faucet

Few people are as synonymous with inventions and innovations as Al Moen. He holds more than 75 patents, but his most revolutionary is the one issued in 1942 for the single-handle mixing faucet he invented in 1937.

As the cliche says, Moen’s invention rose from necessity. While an engineering student at the University of Washington, Moen worked evenings in a garage to pay his tuition. One day he burned his hands while washing them, using a conventional two-handle faucet. From that experience, he resolved to create a faucet that would give the user water at the desired temperature. His first design was for a double-valve faucet with a cam to control the two valves. Moen showed his designs to a major fixture manufacturer, who showed him why the double-valve was the wrong approach. He then went to a cylindrical design with a piston action. Between 1940 and 1945 he designed several faucets, finally selling the first single-handle mixing faucet in San Francisco in late 1947. Since then, single-handle faucets have become so popular that today they can be found in over 40 percent of American homes.

However, Moen’s contributions don’t stop with the faucet. His innovative mind also produced the replaceable cartridge, a push-button diverter, back-to-back installation, and the swivel spray. For all his achievements, Moen’s been nominated for the Inventers Hall of Fame sponsored by the U.S. Patent Office. In addition, this year he was named to the National Kitchen & Bath Hall of Fame for his achievements.



With a flush valve installation, water flows under pressure from the supply piping directly to the fixture, and stands ready for repeated operations.

Sloan Valve Co.’s Flush Valve

William E. Sloan applied for a patent on his Royal Flush Valve June 13, 1906, and on Dec. 6, 1910, he was issued Patent Number 977,562. With a flush valve installation, water flows under pressure from the supply piping directly to the fixture. Because of this connection to the water supply they stand ready for repeated operations. Also, because the water passes through the flush valve under pressure, the fixture is flushed with a scouring action to ensure proper cleansing. These two features, among others, are responsible for the popularity of flush valves in commercial buildings.

The first flush valves produced by Sloan Co. were designed for manual operation. Today, state of the art is flush valves are sensor-operated to make flushing automatic.

Through the 85 years that Sloan Valve Co. has manufactured the Royal flush valve, about 120 different companies have been in the same business at one time or another. Today only a few remain.



In 1896, Halsey W. Taylor wanted to provide safe, sanitary drinking water in public places.

Halsey Taylor’s Double Bubbler

In 1896, Halsey W. Taylor lost his father to typhoid fever caused by a contaminated water supply. This personal tragedy led the young Taylor to dedicate his life to providing a safe, sanitary drink of water in public places. His quest led to the invention of the Double Bubbler™, which projects two separate streams of water that converge to provide a fuller and more satisfying drink. The Double Bubbler also ensures that people drink far away from the actual projector.

Taylor founded the company that bears his name in 1912. He developed his two-stream Mound building projector, as it was called then, for the U. S. government during World War I. Soon after, in 1926, he perfected and patented what is now known as the Double Bubbler.



Robert Zell’s flexible supplies were on the leading edge of the industry’s transition from rigid, galvanized iron pipe to flexible copper plumbing.

Brass-Craft’s Flexible Plumbing

Robert Zell created flexible plumbing supplies from brass bar stock and copper tubing in the basement of his home in Royal Oak, Mich., in 1939. However, because of wartime material shortages, the product wasn’t in production until Brass-Craft Mfg. Co. was founded in 1945.

Zell’s flexible supplies were on the leading edge of the industry’s transition from rigid, galvanized iron pipe to flexible copper plumbing. These supply lines connected stub-out plumbing from the wall to plumbing fixtures such as faucets and toilets. Flexible copper supplies made it possible for the plumber to design an easily-installed supply stop beneath a sink and toilet. Before this, most homeowners had to turn off all the water to the house to service one leaking faucet.



Eljer’s Vitreous China Water Cistern

Invented by one of the original founders of Eljer in 1903, the vitreous china water closet cistern replaced the wall-hung wooden or copper-lined wooden cisterns used to flush a water closet. The vitreous china model received a great deal of resistance from the trade and the public. The strength of the product was doubted so acceptance was slow. To prove just how sturdy china really was, Eljer hosted a demonstration. The cistern was laid on its back on a steel rail, a plank was placed on top of it and 27 men stood on it.

The round cistern was used by Eljer for approximately seven years. In 1908 the company introduced the first rectangular cistern that was cast in a mold—the method used in the plumbing industry today.

Delta’s Single-Handle Ball Valve

In designing the first ball valve in 1945, Landis H. Perry had a specific objective: "To provide a combined volume and blending control valve having relatively simple and yet effective means for sealing the valve element." Beyond that, Perry also sought to create a design that could be repaired with "a minimum of difficulty."

A patent was issued for Perry’s ball valve in 1952. Shortly thereafter, Alex Manoogian purchased the rights to the patent and introduced the first Delta faucet in 1954. Manoogian, the founder of the plumbing industry giant Masco Corp., immigrated to the United States in 1920 to escape the genocide of the Armenian Christian minority by Moslem Turkey. His driving ambition was to make enough money to send for his family who had fled to Greece in 1922 to escape the mounting pogroms.

The Delta single-handle faucet was the first to use a ball-valve design and it proved very successful. By 1958, just four years after the product was unveiled, Delta’s sales topped $1 million.

Whitlam’s Ready-Made Pipe Thread Sealant

J. C. Whitlam II was the first to formulate and market a ready-to-use thread sealant in 1900. While working for a paint manufacturer in the late 1890s, Whitlam watched plumbers buy red or white lead pigments and linseed oil to mix together and use as a paste thread sealant. Whitlam began experimenting in his kitchen on a nonpoisonous, ready-made product. By 1900 he had perfected a gray paste he called Tyte-Unyte that did the job better, at less cost and was safe to use. Whitlam set up a small manufacturing facility in Cleveland, but demand soon exceeded his production capabilities. In 1912 he moved to Wadsworth, Ohio, and built a factory to market Tyte-Unyte throughout the world.

ITT’s Hydronics Technology

In 1905 Hoffman Specialty designed and patented the float and thermostatic-type automatic steam vent for one-pipe steam heating systems. Prior to this invention, vents were mostly bi-metal, which allowed some condensate to drain through the vent. The principle of the float and thermostatic vent for one-pipe steam systems is used by nearly all manufacturers today.

In the mid to late 1920s, McDonnell & Miller manufactured automatic boiler waterfeeders to combat the high number of boilers being damaged by dry firing, which is caused by a lack of water. In the early 1930s, McDonnell & Miller was granted a 17-year patent on its development of a cool-water feed valve.

Spirotherm’s Air Eliminator

The Spirovent was an outgrowth of an attempt to design highly-efficient liquid heat exchangers. In 1972, Frans Roffelsen experimented with new types of heat exchangers using water-based test installations. He found no brand of air eliminator available that removed enough air to avoid distortion of the testing results.

The cyclical growth and release of microbubbles, due to temperature changes, led to faulty test results. Last century, the theory behind this absorption process was already described in Henry’s Law stating that the amount of gas absorbed by a liquid is defined by temperature and pressure.

A research project eventually led to the creation of the Spirovent air eliminator. The special Spirotube inside the Spirovent proved to be the essential part that separated all air, including microbubbles, originating in the heat source. This enabled water to absorb even trapped air at remote and inaccessible areas. In conjunction with a reliable air valve mechanism, without a cap to insure uninterrupted working, it became a mature product ready for mass production.

Today, Spirovent helps eliminate annoying noises from circulators and piping, along with high maintenance costs and callbacks for manual bleeding of hydronic heating or chilled water systems.

Cherne Industries’ Test-Ball Plug

Some clever inventions are stunning in their simplicity. A great example is the pneumatic Test-Ball® Plug developed in 1952 by Lloyd Cherne.

He was on a job in northern Michigan when, much to his dismay, the cast iron mechanical plug he was using (the only plug available at that time) to conduct the stack test would not fit through the cleanout tee. So he purchased a rubber playground ball from a Woolworth store, vulcanized a stem on it, and came up with a crude pneumatic test plug.

Returning to his home base in Minnesota weeks later, Lloyd began experimenting with his idea and within six months began making Test-Balls similar in design to the same style Cherne Industries makes today, bringing them to market in 1953.

The Cherne invention simplified the steps taken to test plumbing in a building, and greatly contributed to the now universally accepted practice of mandatory testing. The plumber now had a test plug that could be used in all common pipe I.D.s, that could conform to out-of-round pipe, that was guaranteed to handle common test pressures and, best of all, was much safer when used with an extension hose than cast iron mechanical plugs.

Initially produced in sizes 1-1/4 inches through 6 inches and catering only to the plumbing trade, the company eventually developed pneumatic plugs up to 120 inches in diameter, serving virtually any pipeline need throughout the world.

Elkay Takes Pressure Off The Cooling Tank

Elkay Mfg. Co. made a major breakthrough in 1974 with the invention of its non-pressurized water cooling tank.

Until then, most water cooler tanks were kept under pressure. Elkay engineers noted that with cold water under continual pressure within a cooler, a water leak or rupture could develop overnight or over a weekend, going undetected for many hours or days and causing extensive damage to the surroundings.

In the new design, the only water under pressure was the water from the source up to the valve and the regulator cartridge. When activated, the push button valve opened to allow water to flow into the cooling tank and then out the bubbler. In the unlikely event of a burst tank, only the stored water within the cooling tank would be released.

Halsey Taylor’s Combination Coolers

Air conditioned comfort on the hottest, muggiest days. A cold drink of water just a few steps away.

These are but a few of the conveniences provided by our industry that modern America takes for granted. The elder statesmen and women among us grew up in an era when life was not so easy, however.

That’s why Halsey Taylor in the 1920s made a big impact with its line of "Combination Cooler and Drinking Fountains," as they were advertised. This depiction from a 1925 catalog shows a cutaway view of a product with a 19- by 19-inch ice chamber, 80-pound ice capacity and ice consumption of approximately 1 pound per capita per day. The drinking water did not come into direct contact with either the ice or melted ice water, but was circulated through a brass coil tinned both inside and outside.

What did a state-of-the-art Automatic Control Combination Cooler & Drinking Fountain sell for in those days? $72.

The T-Drill System

The T-Drill System of mechanically formed tee connection was invented in 1967 in Finland by a plumber/engineer named Leo Larikka.

Mechanical formation of tee connections had been around for many years, but Larikka developed a more sophisticated method that became the most widely adapted system of its kind in the world. In fact, in Scandinavia they do not put in tees—they put in "Larikkas," just as we use "Kleenex" tissues and "Xerox" documents. Patents were not pursued until the early 1970s, though the second- and third-generation T-Drills have since been patented.

As plumbing wholesalers are few and far between in Finland, Larikka developed his invention out of necessity. Lacking the right size tee fitting, he came up with a way to create what he needed out of the tube itself.

Before this method of installation could be widely used in North America, national, state and local codes had to be rewritten after suitable testing. Now, 15 years after introduction here, most plumbing codes are complied with and the method is in compliance with ANSI B 31.5 (ASME code for pressure piping) and being used by more than 5,000 plumbing, mechanical and sprinkler firms.

The fast-track installation afforded also necessitated special inclusion in labor calculator manuals. According to the company, three out of the four major plumbing and mechanical cost data books now reference the Mechanically Formed Tee Connection.

Slant/Fin’s Heat Exchange Fins & Assembly

Patented in 1959, this high performance heating element featured double bent, lighter weight fins with interlocking tongue and groove collars.

Prior to this invention, finned tube radiation frequently got distorted by handling during installation with a consequent reduction in heating output. Making the individual fins thicker and stiffer helped resist distortion, but also made the radiation clumsier to handle and thereby led to rough treatment. Heavy fins also had sharp or rough edges due to their manufacturing process, presenting a hazard to the installer. Still another drawback was the "reed" effect, a vibration resulting from temperature changes.

The heat exchange fin concept eliminated these drawbacks via an interlocking and fin-touch-fin design. When assembled, these fins supported one another for added strength. Accordingly, the individual fins could be made of lighter-weight material without sacrificing durability.

A result was greater heat transfer, enhanced by the flue effect introduced by the side engagement of the fins in the assembly. The lighter-weight fin material also made for quicker space heating. In addition, the fins were devoid of corners and edges and thus less likely to cause injury. Finally, their interlocking arrangements enabled them to maintain constant contact, which eliminates the "reed" effect.

Wirsbo PEX Tubing

In 1968 Thomas Engel invented a process for producing chemically cross-linked polyethylene (PEX) tubing. Considered impossible by many heating industry experts, Wirsbo Co. used Engle’s technology to develop a practical manufacturing process for PEX tubing. The cross-linked tubing was introduced to the European floor heating market in 1972 and potable water market in 1973.

PEX tubing solved a number of problems that occurred with metal pipes and some other types of plastic tubing. PEX will not corrode or erode, and is immune to the many problems associated with poor water quality that can damage metal pipes. The tubing is rated at 180 degrees F., 100 psi. Wirsbo tubing also has the highest polymer oxygen diffusion barrier of any tubing in the world, according to the company.

The growth of cross-linked polyethylene tubing has been dramatic in the European market. Today about 10 percent of all plumbing installations are made with PEX tubing, and in some countries over 50 percent. In Europe, where radiant floor heating is installed in more than 50 percent of all new construction, PEX tubing goes into approximately 70 percent of all jobs.

Wirsbo-PEX was introduced to the U.S. plumbing market in 1985 by Tomas Lenman. Now director of technology at Wirsbo Co. in Apple Valley, Minn., Lenman was a leading member of the engineering team that developed the product in the early 1970s. Today, PEX tubing products are used for floor heating and other heating applications.

Powers’ Pressure Balancing Initiatives

In 1964, the Powers Regulator Co., now known as Powers Process Controls, patented and formally introduced its Hydroguard™ 410 Pressure Balancing Valve, which protected bathers from steamy blasts or icy bursts by keeping water pressure equalized to the tub or shower.

The 410 used a unique diaphragm-actuated pressure equalizing chamber to sense and correct any change in the water supply. Failure of the cold water supply shut off hot water delivery to protect the bather.

Rugged construction made the valve well-suited for high-use shower applications in hotels, apartment buildings and schools. Powers advertised the Series 410 as a great way to "shower a welcome" on hotel and motel guests … and keep apartment tenants singing as they soap up!

The concept of controlling water temperature through pressure control dates back to 1887, when company founder William Penn Powers equipped his new three-story heating/plumbing business building with Wisconsin’s first central water heating plant.

To eliminate boil-over, he developed a process of controlling the system based on the relative boiling points of water under different pressures. He achieved it via a closed-end, water-filled pipe in the boiler, the other end of which was attached to a diaphragm that controlled a damper.

Haws’ Barrier-Free Electric Water Cooler

Donald Ackland, a retired engineer at the Haws Drinking Faucet Co., invented the first barrier-free electric water cooler in 1973, long before anyone had heard of ADA. The industry’s first wheelchair-accessible electric water cooler mounts 38-1/2 inches from the finished floor for easy access, and includes a front panel, easy-to-operate lever-action bubbler.

Lavelle Industries’ Korky Flapper Tankball

In 1953, Lavelle Rubber Co., now Lavelle Industries, introduced its Korky Flapper Tankball — a simple product that fit over the flush valve and would slide down to the bottom and seal the opening. Prior to 1953, the tank ball for a toilet was a round- or cone-shaped figure with a screw insert that would thread onto lift wires and a fuide arm attached to the flush valve. Often the lift wire would bend or corrode. It would take two to four separate parts to replace this assembly, usually making it a costly and complicated repair.

The Korky Flapper eliminated the additional repair parts, reduced the replacement time and created a positive seal that eliminated leaking. Needless to say, plumbers loved it, with more than 1 million units sold in just four years.

Wolverine Brass’ Ceramic Disc Water Control

Wolverine Brass has been perfecting ceramic disc water control since its original patent was issued in 1973. Unlike cartridges that use rubber in the waterway, ceramic discs are lapped and polished to a degree of flatness that can only be measured in lightbands. In labratory cycle tests with high sand concentration, 27 years of actual use was approximated, and results showed that ceramic disc technology held up.

In-Sink-Erator’s Disposer

Wisconsin architect John Hammes invented the food waste disposer in 1927. In his original model, the disposer ground up the food waste so it could be flushed down the kitchen drain. Hammes tinkered with his original model for 10 years before he launched the In-Sink-Erator Mfg. Co. and its line of disposers.

When disposers were first introduced most municipalities banned them because of worries about their impact on sewage treatment systems. However, by 1960 they were required in new construction by ordinance in more than 100 communities because of their sanitary value. Much like the water closet, a disposer immediately removes raw food waste from the home through sewerage pipes to treatment plants, where it can be treated and neutralized.

After more than 40 years on the market, disposers are now found in more than 50 percent of all households. About 4 million disposers are sold annually.

Watt’s Automatic T&P Valve

Watts Regulator Co. introduced the first automatic temperature and pressure relief valve in the late 1930s. The new valve opened and closed automatically on both pressure and temperature.

Previously, two forms of protection were used. One was the pressure-only relief valve that didn’t control temperature, which was the cause of water heater explosions. The second was a fusible plug-type temperature and pressure relief valve. When the water temperature reached 210 degrees F, the lead plug melted. This created a discharge port and the overheated water flowed to atmosphere. The water continued to discharge until manually shut off.

Watt’s discovery of the T&P valve has nearly eliminated water heater explosions and ensured that these appliances are safe for home use.

Symmons Pressure Balancing Shower Valve

Working with his own hand-made wood patterns in a vacant piano factory in Boston in 1939, Paul C. Symmons invented the first pressure-balancing shower valve and founded the company that bears his name.

Symmons discovered that sudden temperature changes in the shower were caused by pressure changes in the supply lines. Shower water got suddenly hot when someone somewhere else in the building turned on a cold water faucet or flushed a toilet. Conversely, turning on the hot water faucet caused the shower water to turn cold.

Symmons perfected a valve that uses a hydraulic piston as the prime control unit. As soon as the valve is turned on, both hot and cold water exert pressure on opposite ends of the piston, balancing it in the valve. If the hot water pressure drops, the piston reacts and reduces the cold inlet opening. The piston continually equalizes the pressure of hot and cold water, even when supply pressures change suddenly or drastically.

Haws’ Drinking Faucet

Luther Haws was a self-employed plumber and sheet metal contractor in the early days of the 20th century. To those occupations, he added the job of sanitary inspector for the city of Berkeley, Calif. It was his role as an inspector that led to his invention of the first drinking fountain. In 1905, while on his rounds at a public school, Haws noticed the children drinking water out of a common tin cup that was chained to the faucet.

He knew this wasn’t a sanitary situation, so when he returned to his plumbing shop he fiddled with some spare parts. Using available plumbing parts — the ball from a brass bedstead and a self-closing rabbit ear valve — Haws assembled the first drinking faucet. He showed his new invention to the Berkeley School Department, which installed some of the first models.

Haws eventually gave up the plumbing company and formed the Haws Sanitary Drinking Faucet Co. in Berkeley in 1909. He received a patent on his product in 1911.

Milwaukee Electric Tool’s Sawzall

Invented by Metco engineer Ed Ristow, the first Sawzall was sold in 1949, nine years before a patent was finally granted. Ristow’s Sawzall incorporated a reciprocating mechanism with only three moving parts designed to provide a 3/4 inch stroke at 2,250 strokes per minute.

At the time, the only similar tools on the market were drills with reciprocating attachments. They were heavy and required two hands to operate. The Sawzall weighed only 6.74 pounds and, with the right blade, could efficiently rough-out any shape in wood, plaster, metal or plastic.

Links