The 3/4-inch Female hose thread (FHT) x Male hose thread (MHT) atmospheric vacuum breaker (AVB) prevents contaminated water flowing from the irrigation system back into the culinary system. Modern plumbing code for new construction usually requires that any faucet which is attached to the home water supply have an AVB, but older homes might not have one. For the AVB to be effective you must install it at least 12 inches above the highest point of the hose and hose-end device. Typical installation is to directly attach the AVB to the hose faucet with any add-on devices such as a hose faucet controller, pressure regulator or filter coming after it. A corrosion-resistant brass set screw gives extra security on the hose faucet. For outdoor irrigation use with cold water only.
For preventing backflow of irrigation water into culinary water systems
Robust “poppet” design opens when watering and closes when water is off
Brass set screw attaches the device securely to the hose faucet threads
Compatible with North American hose faucet threads
Fits all standard outdoor hose faucets
Female hose thread inlet x male hose thread outlet
Prevents outside water from siphoning through and outside faucet
For outdoor and cold water use only