Backflow prevention device and vacuum breaker for kitchen plumbing

A backflow prevention and vacuum breaker device for connection between a potable water supply and a faucet to prevent backflow and back siphoning of contaminated water into a potable water supply, comprising:

• a mixing cartridge and a vacuum breaker cartridge, said vacuum breaker cartridge connected to said mixing cartridge and being disposed below said mixing cartridge,
• said vacuum breaker cartridge having a body having fluid entry means for receiving potable water from said mixing cartridge, fluid exit means for directing potable water towards said faucet, and backflow prevention means located between said fluid entry means and said fluid exit means,
• said backflow prevention means having a chamber having an entry port contiguous with said fluid entry means, an exit port contiguous with said fluid exit means and a back flow prevention port which is open to atmospheric pressure;
• and a gravity biased valve disposed in said chamber and movable between a first seated position sealing said entry port and a second raised position sealing said backflow prevention port;
• whereby potable water flowing downwardly into said chamber from said mixing cartridge from said fluid entry means is directed upwardly towards said entry port, moving said valve from said first seated position to said second raised position to prevent water leakage through said backflow prevention port thereby permitting potable water to flow through said chamber, out said exit port and along said fluid exit means, and said gravity biased valve returning to said first seated position in the absence of water flow, thereby opening said backflow prevention port, returning said chamber to atmospheric pressure and preventing backflow of contaminated fluid into the potable water supply.