For most people, clean water comes in from the municipality’s water main or a communal source such as a well. This water is then diverted throughout the house for many different purposes: drinking and cooking, laundry, bathroom use, irrigation, etc. Once it is used, however, the dirty water must be treated in order to kill any bacteria or other pathogens as well as remove chemicals that now taint the water. If this dirty water flows back into the clean supply, it can cause illnesses and even death. Backflow preventers work to stop this problem.
Water wants to flow from an area of high pressure to an area of lower pressure. Normally, the water flowing through the main supply line is highly pressurized to force it to flow into your house. However, if something happens like a supply line break or water shortage, the pressure in the main can drop. Then, dirty water wants to flow backwards into the main. Backflow preventers stop the path of water from flowing back.
Unclean water can flow back into the clean supply at any source; thus, there are several different types of backflow preventers to fit different needs. For instance, if water that flows out of your sink faucet goes back into the faucet, it can contaminate the clean supply. Most sinks rely on a simple air gap to prevent backflow. Because the faucet is several inches above the edge of the sink, the sink cannot overflow and reach the faucet. Instead, the dirty water overflows onto the floor. The dirty water would only reach into the faucet if the entire room filled with water to the height of the faucet.
However, most other backflow preventers rely on complex systems of pressure check valves and reduced pressure zones to prevent contamination. Over time, the constant battle to maintain pressure and prevent contamination can wear down the parts of your backflow preventer. To keep your backflow preventer in top shape, it is important that you get these devices regularly serviced so that any damaged or worn parts can be repaired. Parts that may need regular service and repairs include:
Check modules and seats
Cam check disc assemblies
Single and double-check valves
Reduced pressure zone assemblies
If your backflow preventer device fails, you can be held financially responsible for allowing dirty water to infiltrate the clean supply. Thus, it is important to rely upon preventative measures to avoid these disasters rather than wait to service your device until it is too late.