Written by Sean Cleary 4:19 pm ASSE, Backflow Prevention

ASSE 1055 Chemical Dispensers

The Most Misunderstood Product in the Cross-Connection Control Industry

When it comes to a lack of understanding in the cross-connection control world, I don’t think there is another product that is as misunderstood or incorrectly installed as the chemical dispenser. Discussions about this product are even more heated than the often argued about protection required for carbonated beverage dispensers. Both of these situations bring out the “You must install a reduced pressure principle backflow prevention assembly on every installation” crowd, along with many others who simply do not understand how chemical dispensers work or understand the proper installation of this appliance. Let’s take some time and start at the beginning.

The first question we need to answer is, “What is, and what is not, an ASSE 1055 approved chemical dispenser?” That makes a big difference in the discussion. Some in the industry think that adding an ASSE 1052 hose connection backflow preventer or a bleed valve arrangement converts a chemical dispenser into an approved ASSE 1055 chemical dispenser. That is completely wrong and false. The title of the product standard for chemical dispensers has been reworded to more accurately reflect what the product is. The 2009 and 2016 editions of ASSE 1055 were titled Performance Requirements for Chemical Dispensing Systems. In 2018, the title was updated to better reflect what the product actually is. The title of the current standard is Performance Requirements for Chemical Dispensing Systems with Integral Backflow Protection. This new title explains what the devices have been all along – chemical dispensers with built-in backflow protection that require no additional backflow protection if installed correctly. New changes were made to the updated 2016 and 2018 standards. The elimination of Type A and Type B category dispensers is an example of the differences between the standard versions. The Type A category in the 2009 standard was developed to reflect pressurized chemical dispensers. No pressurized dispensers were ever listed to the ASSE 1055 standard, so the standard now only allows for non-pressurized dispensers. The requirement for backflow protection, however, existed in every version of the standard.

The ASSE 1055 standard requires that before a chemical dispenser is approved, it must be laboratory tested for a number of possible situations, including tipping, pressure and temperature deterioration at rated temperature and pressure extremes, hydrostatic pressure, backpressure, and backsiphonage. If it passes the laboratory testing and becomes a listed product, inspectors and consumers can have the confidence that the device will deliver the needed protection. So, the first step for installers and inspectors is to make sure the dispenser is a listed and approved ASSE 1055 chemical dispensing system. There are a number of products on the market used to dispense chemicals but are not listed or tested to the ASSE 1055 standard.

The next consideration is the water supply to the device. Using a dedicated water supply line to the ASSE 1055 dispenser is the most effective installation method. Since the dispenser has the necessary protection built into it, no extra protection is required. At times we see installations where extra protection is added. This double, or in some cases triple, protection is an unfair burden to the end user. The problem is that many installers and or inspectors do not understand the installation requirements.

The 2018 model plumbing codes have addressed the protection requirements for chemical dispensing equipment. The International Plumbing Code (IPC®) states in Section 608.16.7, “Where chemical dispensers connect to the potable water distribution system, the water supply system shall be protected against backflow in accordance with Section 608.13.1 Air-Gap, 608.13.2 Reduced Pressure Principle Backflow Prevention Assembly ASSE 1013, 608.13.5 Pressure Vacuum Breaker Assembly ASSE 1020, 608.13.6 Atmospheric-type Vacuum Breaker ASSE 1001, 608.13.8 Spill-Resistant Pressure Vacuum Breaker Assembly ASSE 1056, or 608.13.9 Chemical Dispensing Backflow Device ASSE 1055.” So, the installation of the ASSE 1055 dispenser meets the backflow protection requirements of the IPC, no additional protection is needed.

The 2018 Uniform Plumbing Code (UPC®), Section 603.5.21, deals with chemical dispensers specifically. The section states, “The water to a chemical dispenser shall be protected against backflow. The chemical dispenser shall comply with ASSE 1055 or the water supply shall be protected by one of the following methods: Air-Gap, Atmospheric Vacuum Breaker, Pressure Vacuum Breaker Assembly, Spill-Resistant Vacuum Breaker Assembly, or Reduced Pressure Principle Backflow Prevention Assembly.” So, again, the installation of a listed ASSE 1055 dispenser is all the protection required.

The most common problem with the installation of chemical dispensers is the absence of a dedicated water supply. In this case the installer, who in most cases is not a licensed plumber, must locate a water source for the dispenser. The dispenser is most often installed in a janitor closet or in a commercial kitchen.

The only available water supply is the faucet on the service or mop sink. This is where the installation issue occurs. In most cases, the faucet contains an atmospheric vacuum breaker (AVB) as the required backflow protection on the sink faucet.

ASSE 1001 AVBs are non-testable backflow prevention devices. In many conversations we have around the country, we at times run into installers and inspectors that have gotten bad information about AVBs and what plumbing codes and standards say about them. One common thing we hear is that AVBs are only approved for low hazard protection. For example, an installation guide for chemical dispensers put out by the Arizona Department of Public Health states that the AVB is not designed for use in high or health hazard applications (e.g., soaps, sprays, degreasers, chemicals, and similar contaminants). All model plumbing codes and ASSE 1001 are clear that an AVB is approved for high and low hazard backsiphonage protection. The University of Southern California Foundation for Cross-Connection Control and Hydraulic Research Manual of Cross-Connection Control, Tenth Edition, states that the AVB will protect against both pollutants and contaminants. Properly installed, the AVB is high hazard protection. We also hear that non-testable devices are not allowed on high hazard applications or in commercial facilities. Unless your jurisdiction has amended the codes or has specific regulations in place, the AVB is high hazard protection.

If we do encounter the faucet being used as the water supply, several problems can occur. One problem is related to the installation height – an AVB is required to be mounted six inches above all downstream piping. Chemical dispensers in most cases are mounted at an elevation above the faucet AVB. The elevated piping could cause backpressure on the AVB, which it is not designed for or to protect against. Another issue is that the chemical dispenser contains a shutoff valve. That could put the AVB under continuous pressure (defined as pressure for more than 12 hours in a 24-hour period). The ASSE 1001 AVB standard was updated in 2017. A significant change to the standard was the removal of a sentence in Section 1.1 Application that read, “The device shall be installed downstream of the last control valve.” This would prohibit the installation of an ASSE 1055 dispenser downstream of a faucet AVB. That statement was replaced with the following language in the updated standard: “The device shall have its outlet open to atmosphere,” which would allow a valve downstream provided some part of the outlet piping was open to atmosphere at all times. This one line changed the installation requirements significantly. It allowed for the possibility of the faucet with an AVB to be used as the water supply for an ASSE 1055 chemical dispenser, as long as the installation has continuous water flow when the faucet is open. IAMPO PS-104-97, Material and Property Standard for Pressure Relief Connection for Dispensing Equipment, is designed to protect against both backpressure and continuous pressure. When installed, it ensures a continuous flow of water though the bleed valve device whenever the faucet is open, making backpressure on the AVB impossible.

Many Authorities Having Jurisdiction (AHJ) are having issues with the installation of this equipment. That is why it’s important that we examine all the possible options, including the use of the bleed valve device. Several AHJs consider these devices shutoff valves. These devices are not. They also say bleed valve devices can create backpressure on the faucets AVB. These devices cannot create backpressure. Another reason we hear from the industry is that they have a high failure rate. However, I have seen no studies or documentation showing that this is true. AHJs need to look at these situations with an open mind and not simply revert to the “reduced pressure principle backflow preventer should always be installed” answer.

We should work for inspections on this equipment when it is installed. Installation standards should be developed and enforced. A dedicated water supply should be used whenever possible, and in new construction, these water supplies should be part of the design criteria on any commercial construction. The Dispenser Equipment Alliance (DEA) is an industry group looking at this issue, working to develop these installation standards, and educate the public and the industry about this equipment. Visit www.dispensingequipment.org for more information.

Code changes are being proposed to remove any confusion about how these devices can and should be installed. It’s time for AHJs to take a fresh look at the installation of chemical dispensers, the way they work, and how they should be installed. The information is available – the products and standards have changed. Let’s move forward with safe procedures and products to protect the public water supply.

Article first published in Working Pressure magazine

Sean Cleary

Sean Cleary has been a member of United Association Local 524 Scranton, Pa. for more than 40 years. He has worked in all phases of the plumbing and mechanical industry, and is a licensed master plumber. Cleary is a past president of ASSE International and past chairman of the ASSE Cross-Connection Control Technical Committee. He is employed by IAPMO as the vice president of operations for the Backflow Prevention Institute (BPI).

Last modified: December 19, 2023