An air gap is a vertical, physical separation between the end of a water supply outlet and the flood-level rim of a receiving vessel. This separation must be at least twice the diameter of the water supply outlet and never less than on inch.
An air gap is considered the maximum protection available against backpressure backflow or back-siphonage but is not always practical and can easily be bypassed.
What is a Reduced Pressure Zone Assembly?
A reduced pressure zone assembly protects water from substances that may contaminate water causing illness or death. A sprinkler/irrigation system that has a chemical feed requires this device. It is also commonly used in commercial establishments to protect against numerous contaminants. These devices must be installed above ground.
What is a Double-Check Valve Assembly?
A double-check valve assembly protects water from substances that may pollute but not contaminate the water. For instance, sprinkler/irrigation systems are required to be protected by these devices. They are normally installed near the meter in an underground box.
What is a Hose Bibb Vacuum Breaker?
A hose bibb vacuum breaker (HBVB) is one of the least expensive and most commonly used backflow preventers. When attached to an outside water tap, these backflow preventers keep water that may be contaminated with fertilizer or insecticide from entering your drinking water.
You should attach an HBVB if you have a sprayer on your hose.
Where Can I Get More Information About Cross-Connection Control?