| 摘要 |
<p>A self-draining hose connection vacuum breaker and backflow preventer having a flexible annular diaphragm and a coacting seat disc movable relative thereto which, together, function to prevent backflow through the device and with the annular diaphragm coacting with atmospheric vents to provide a vacuum break and fluid drain, A movable piston has two different positions, dependent upon whether or not a hose is connected to the device, with the piston mounting the seat disc for movement therewith and relative thereto whereby the seat disc and annular diaphragm coact to prevent backflow when a hose is attached to the device, but the seat disc is postponed to permit flow through a central opening of the annular diaphragm when a hose is removed from the device to prevent trapped water in a source valve, such as a faucet or the like, which could result in either pipe and/or valve rupture resulting from freezing or retention of stagnant water which could result in bacterial growth.</p> |
