Please click on the questions below for more in depth explanations.
- What is backflow?
- What is a cross-connection?
- What is backpressure?
- What is backsiphonage?
- What is a backflow preventer?
- What is a reduced principle assembly (RP)?
- What is a double check valve assembly (DC)?
- Why do backflow preventers have to be tested periodically?
- Where can I get more information about cross-connection control?
- How often must I have my backflow prevention device tested?
- Reference Links
1. What is backflow?
Backflow is an undesirable reversal of the flow of water than is normally intended.
2. What is a cross-connection?
A cross-connection is any physical connection or arrangement between two otherwise separate pipe systems, one of which contains potable (drinking) water and the other containing a contaminated source.
3. What is backpressure?
Backpressure is a backflow cause by a downstream pressure that is greater than the upstream or supply pressure in a public potable water system.
4. What is backsiphonage?
Backsiphonage is the flowing back of fluid from a plumbing fixture or other source cause by negative pressure.
5. What is a backflow preventer?
A backflow preventer is a mechanism that prevents backflow. The principle types of mechanical backflow preventers are: the Reduced Pressure Assembly (RP), the Pressure Vacuum Breaker Assembly and the Double Check Valve Assembly (DC). A secondary type of mechanical backflow preventer is the residential dual check valve.
6. What is a Reduced Principle Assembly (RP)?
An RP is a mechanical backflow preventer that consists of two independently acting, spring-loaded check valves with a hydraulically operating, mechanically independent, spring-loaded pressure differential relief valve between the check valves and below the first check valve.
7. What is a Double Check Valve Assembly (DC)?
A DC (valve assembly) is a mechanical backflow preventer that consists of two independently acting spring loaded check valves. A DC is effective against backpressure and backsiphonage, but should only be used to isolate non-health hazards.
8. Why do backflow preventers have to be tested periodically?
Backflow prevention devices break or wear out just like parts of a car. If tested annually, you will help ensure that the drinking water in your home remains safe. Licensed plumbers who also carry a Backflow License can inspect, test, repair or replace backflow prevention devices.
9. Where can I get more information about cross-connection control?
Information on this and other related topics is abundant, and can be found in the reference links below.
10. How often must I have my backflow prevention device tested?
It is required that you have your backflow prevention device tested at least once a year.
Reference Links:
United States Environmental Protection Agency
Illinois Environmental Protection Agency - Bureau of Water
American Society of Sanitary Engineering