November 15, 2010
Although vacuum breakers exist in many different shapes and sizes, the most common example can be seen on outside hose bibs (outdoor faucets). The vacuum breaker simply assures that water cannot flow backward into the system beyond the breaker itself. Inside a vacuum breaker is a poppet valve that is held up by the water pressure within the system which prevents air to enter the device. When the pressure drops, the poppet valve drops and allows air to enter the system which breaks the siphon.