The right dispenser valves are key in protecting beverage consumers according to Julius Ballanco in this month's Plumbing Primer.

One of the major adjustments I needed to make when I moved to the Midwest was relearning the term used for identifying a carbonated soft drink. In the Chicago area, the drink is referred to as "pop." (I always thought that pop was an expression for my father.) Out on the East Coast, I grew up calling these drinks soda.

Whether you drink soda or pop, have you ever thought about the water quality used to make these beverages? If it comes from a bottle or can, the quality of the beverage is regulated completely by the soft drink manufacturer. However, if it is from a drink dispenser, the water supply is an important part of the equation. Without adequate protection, that water can destroy the quality of the soft drink.

First, a little background in the chemistry of a carbonated beverage dispenser. (No, I don't know the secret formula of Coca Cola^R.) To have a carbonated beverage, you need carbonation. The carbonation comes from carbon dioxide, or CO₂ gas. The CO₂ gas mixes with the water (H₂O) to form carbonic acid (H₂CO₃). This is the fizz in soda. The carbonic acid is mixed with syrup to produce a carbonated beverage.

When everything goes according to plan, you receive the beverage of your choice from any drink dispenser. The problem occurs when carbonic acid, which is highly corrosive to copper and copper alloy found in many drink dispensers, reacts to the metal and creates an excess of copper in the water used to produce soda. When this happens, the person consuming the beverage gets a bad drink. Depending on the amount of copper in the water, you can get a terrible stomachache. There are cases of vomiting, as well as trips to the hospital. While I don't know of anyone dying, some attacked by copper poisoning said it felt like they were dying. So maybe you thought manufacturers were being cheap by not using copper tubing inside a dispenser when in fact, they are protecting your beverage.

How To Protect Pop

Enough on the history. Anytime a potable water line supplying a soft drink can be contaminated, there's concern on the part of the plumbing industry. I first got involved with protecting carbonated beverage dispensers in the 1980s. All of us in the industry cried for adequate beverage protection, yet we had nothing to offer the carbonated beverage industry.

At first, backflow manufacturers started making up valves. Some plumbing codes went to the extreme of requiring all carbonated beverage dispensers to have the water supply protected with a reduced pressure (rp) principal backflow preventer. Just think of how many dispensers there are in the United States, then think of the number of reduced pressure valves needed, plus the annual testing of these valves. While this may sound like a good method of protection, a reduced pressure principal backflow preventer provides no protection when it is made out of brass. It may keep the carbonic acid from migrating to the rest of the potable water system, but it still contaminates the soda the next time the dispenser is used.

In the late 1980s, ASSE started a project to establish a standard for a new vented double-check valve to protect the water supply to carbonated beverage dispensers. For years, dispenser manufacturers installed a double-check valve on the water supply inside the units. ASSE 1032 regulates these valves. The problem for the plumbing industry is the valves have no atmospheric vent. Hence, if there is a failure, there is a possibility of carbonic acid flowing back to a copper water line. The new standard was designated ASSE 1022. Most of us thought the standard would develop quickly. Unfortunately, ANSI did not approve ASSE 1022 until 1998. The first product listed to this new standard did not appear until the beginning of 1999.

The new valve has two check valves and an intermediate atmospheric port. The valve also is required to have an internal 100-mesh screen. The typical materials used to make these valves are stainless steel and plastic.

Shortly after these new valves hit the marketplace, I received a call from the National Soft Drink Association. This is the trade association for the big soda companies. It asked for help in solving the inconsistencies among the myriad plumbing code requirements across the country regarding backflow protection. It readily admitted it didn't understand the plumbing industry nor the backflow requirements.

In the first meeting with the industry representatives, I had my entire spiel ready to sell them on the use of the new ASSE 1022 device. I started explaining, when a representative from a major soft drink manufacturer asked, "Is this the highest level of protection we can provide the public?" I responded, "Yes." He then added, "That's it, we'll switch to using these backflow preventers inside every beverage dispenser."

I was a little disappointed. I thought I needed all this technical information to sell the concept. All the industry wanted was the highest level of protection for the public. It was the easiest sell in backflow I've ever had.

Not So Fast

The soft drink industry announced last year it is switching all new carbonated beverage dispensers to an internal ASSE 1022 device for backflow protection. The manufacturers of ASSE 1022 backflow preventers were caught by surprise. They didn't have the inventory nor the manufacturing capacity to supply all the valves needed for this switch. Apparently, they also thought it would be a hard sell.

Within the past few months all that has changed. New dispensers now are rolling off the production line with internal ASSE 1022 devices, or internal air gaps. As a result, the water supply is protected and you can simply connect the potable water to the dispenser without any external backflow preventer.

What about the older carbonated beverage dispensers? For the older dispensers, you need to provide an external ASSE 1022 backflow preventer. Whenever you are doing any work in a fast food restaurant, quick shop, restaurant, nightclub or other location with a carbonated beverage dispenser, check to make sure the dispenser has the correct backflow preventer. It needs either an internal or external ASSE 1022 device.

Now, for a little secret. If you encounter a dispenser with a built-in ASSE 1032 device, which is the wrong one under new plumbing codes, and no external ASSE 1022 device, have the owner of the facility contact his distributor. The distributor, typically a soda company under contract, will replace the ASSE 1032 device with an ASSE 1022 as a part of its service contract with the facility. This is how dedicated the major soft drink companies are in protecting of the potable water supply.

Help out your customers by making sure they always drink a carbonated beverage free of high copper concentration.