What is a cross connection?
Wherever physical cross connections exist between a potable and non-potable water, there is the potential for backflow to occur.
What is backflow?
Backflow is a flow of solid, liquid or gas from any source opposite to the normal direction of flow, back into the potable water supply or system due to back pressure or back siphonage.
Back Pressure – is any condition where the pressure in a system becomes greater than the supply pressure feeding the system. It’s caused when a potable system is connected to a non-potable system that is operating at a higher pressure. Non-potable substances may be forced into the drinking water supply
Back Siphonage – is caused by negative or reduced pressure in the supply piping. When pressure in a distribution system drops to atmospheric or below, a vacuum is created allowing water to siphon in the reverse flow. This condition is identical to drinking through a straw
What does this mean to you?
Depending on your business, property ect. It means if there is ever a backflow situation that occurs, and you do not have a backflow preventer in place, your water from your pool for example, could be siphoned back into your potable water, thats the same water you and your family use to drink, in turn possibly harming you and your family.
If you have irrigation, and one of the lines is broken, cracked and theres break in the municipal water main, and you’re not protected by a backflow preventer, you are facing the same scenario, except now you’re potentially facing fertilizers and whatever else may be in the ground/soil being pulled through into not only your drinking water, but all of those around you.
These are very basic examples and happen more commonly than one may think.
When you get into more complex systems and commercial and industrial buildings and properties such as Morgues, Farms, Universities, Butchers, Restaurants, Bars, Distilleries, Breweries, Pharmaceutical Plants, Zoos, Mines, Mills etc. these are all examples of Severely HIGH RISK Cross Connections and Require the upmost protection.
Some engineers may even make the decision to double up on certain valves for ultimate protection (but thats their specialty). It’s EXTREMELY IMPORTANT to keep on top of your backflow testing program (our Specialty) as you don’t want to be responsible for contaminating yours, your families, or the publics potable water systems due to neglect.
RPBA – Reduced Pressure Backflow Assembly
Reduced Pressure Backflow Assemblies prevent the reverse flow of polluted water from entering into the potable water supply due to backsiphonage and or backpressure. It consists of bronze body construction (1/4 to 2 in., 8 to 50mm) or FDA approved epoxy coated cast iron (2 1/2 to 3 in., 65 to 80mm), two, in-line independent check valves, replaceable check seats with an intermediate relief valve, and ball valve test cocks. Ideal for protection of health hazard cross-connections or for containment at the service line entrance. Used in Severe Hazard situations. For example; Commercial laundry, sewage lift stations, petroleum processing, food and beverage processing plants, car wash facilities, dental clinics, tall buildings (protection against excessive head pressure) marinas, heat exchangers, etc.
DCVA – Double Check Valve Assembly
Double Check Valve Assemblies prevent the backflow of contaminated water into the potable water supply. It consists of a bronze (1/2 to 2 in) body construction that is easy to maintain and service. These are used in Moderate Hazard situations. For example, steam generators, heating equipment, irrigation systems, swimming pools, vending machines, etc.
PVB – Pressure Vacuum Breaker
“Pressure Vacuum Breakers” and “Spill Resistant Pressure Vacuum Breakers” prevent the reverse flow of polluted water from entering into the potable water supply due to back syphonage. It consists of bronze body construction, silicone rubber check valve disc, plastic check valve seat, stainless steel springs, a bonnet with silicone rubber O-ring seal, a lightweight plastic disc float, tee handle or lever handle shutoffs, and test cocks. Ideal in health hazard continuous pressure applications such as irrigation systems and industrial process water systems where the water enters the equipment at or below its flood rim. Maximum Pressure:150psi (10.3 bar), Minimum Pressure: 15psi (55kPa)