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How much backflow protection is necessary? It is a question we constantly face in the plumbing profession. For more than 100 years, the plumbing industry has safeguarded the water supply by implementing protections from backflow and back-siphonage. The medical profession even recognized that measures taken by the plumbing industry, not medicine, have dramatically reduced waterborne diseases in the United States
More recently, that question regarding the protection of the water supply has arisen with the shutdown of buildings during the COVID-19 pandemic. As water has aged in buildings’ piping systems, do we need additional measures to protect the drinking water
Add to the issue of backflow protection the concern for crossflow, which has plagued the plumbing profession in recent years with the increased use of flow restrictors and diverter valves.
I received a call from a local hospital regarding a major problem during a medical procedure. The instrument being used was cooled by water supplied from a connection to the cold water piping system. During the procedure, the doctor, luckily, noticed the water temperature rising, thus stopping the use of the instrument.
Upon investigation, it was found that a service sink in a janitor’s closet was on the opposite wall of the room in which the procedure was being done. The service sink faucet had a wye connection screwed to the outlet, with one opening going to the chemical dispenser and the other going to a hose to fill a bucket. Both the hot and cold faucets were left in the “on” position with the flow controlled by the wye fitting shut-off.
During the procedure, the cold water dropped in pressure, allowing the hot water to crossflow to the medical instrument, thus increasing the water temperature.
This is an example of a typical situation occurring all too often in a plumbing system. In hospitals and medical facilities, this can be disastrous. In residential buildings and hospitality facilities, crossflow can also lead to scalding.
Integrated Check Valve and Angle Stop
McGuire Mfg. Co., located in Cheshire, Conn., recognized the problems of crossflow and backflow and invented an angle stop to help solve these issues — the ICV Defender integral check valve. It incorporates a spring-activated check valve into McGuire’s heavy-duty angle stop. Thus, the angle stop not only provides convenience to shut off the water supply to a fixture, but also prevents the reversal of flow in the piping system.
The ICV Defender series of angle stops are listed to ASME A112.18.1/CSA B125.1, NSF 372 and NSF 61. As listed angle stops, they comply with the International Plumbing Code, the Uniform Plumbing Code, the National Standard Plumbing Code and the National Plumbing Code of Canada.
In addition to ASME A112.18.1/CSA B125.1, the check valve in the ICV Defender was tested to ASME A112.18.3. This is the standard specifying performance requirements for backflow protection devices used in plumbing fixture fittings. The standard lists aggressive age testing to determine the performance of a backflow device after years of service. It requires backflow protection to be accomplished by a minimum of two backflow devices, one of which must be a check valve.
Having passed ASME A112.18.3 as a backflow check valve, the ICV Defender can serve as one form of backflow protection for hose-connected outlets and hand showers. With a backflow protection check valve rating, the integrated valve will prevent crossflow when supplying hot or cold water to a faucet or fixture fitting. The ICV Defender is a simple solution to a complex problem. Hot water will not flow to the cold water piping, and cold water will not flow to the hot water piping.
There are many applications for this type of device. Plumbing engineers will immediately view this device as an added level of protection for any hospital or health-care facility. These buildings always rely on providing additional levels of protection for the public and patients. Any crossflow or cross-contamination of the water supply can be prevented.
Similarly, plumbing contractors see the need in schools and food-handling establishments to also provide higher levels of protection of the potable water supply.
Stagnant Water Concerns
The COVID-19 pandemic brought to light the concerns of shutting down a major building for a long period of time. Office buildings, schools, hotels, motels and restaurants were closed for months.
All during this time, the water system remained full of stagnant water. Concerns were raised regarding water aging and the possible dissipation of treatment chemicals used to maintain the potability of the drinking water. Many engineering and scientific organizations emphasized the importance of flushing the water supply before reopening these unoccupied buildings. Every opening has been identified as needing to be flushed of stagnant water.
While water aging and chemical dissipation was identified for shutdown buildings, a similar impact on the water supply can occur in the supply to rarely used fixtures or seasonal buildings. The ICV Defender prevents the backflow of stagnant water into the water supply of the building from fixtures that have minimal use. These rarely used fixtures will flush the stagnant water remaining in the piping between the angle stop and the faucet or fixture fitting during the next use of the fixture.
In residential buildings, including hotels and motels, there are many plumbing fixtures used on a limited basis. The ICV Defender can prevent flow reversal from these rarely used fixtures. This will prevent any possible contamination from aged water.
When the ICV Defender was developed by McGuire, its intent was to address issues related to high-risk areas such as hospitals, health-care facilities, food-handling establishments, hospitality facilities and educational buildings. The valves also can be used in any building for any plumbing fixture connection.
Julius Ballanco, P.E., CPD, FASPE, is president of JB Engineering and Code Consulting. He is a past president of the American Society of Plumbing Engineers and past president of the ASPE Research Foundation. He is a member of the ASPE College of Fellows. Ballanco authors two monthly columns on plumbing and mechanical issues. He also has authored a number of books on the plumbing and fire sprinkler codes, as well as design issues. A graduate of Stevens Institute of Technology, he is both a licensed Professional Engineer and a licensed Master Plumber.