With a pressure vacuum breaker, however, a drop in the pressure of the water enables the spring to snap the check valve shut. As soon as the water pressure drops, the check valve closes and backflow does not occur.n a pressure vacuum breaker, the water travels through a check valve and causes a poppet to raise up a guide into an air inlet. The air inlet also has a valve which ordinarily remains closed.
Peter Marshall was born Ralph Pierre LaCock on March 30, 1926, to Ralph and Jean LaCock, a show business family, in Huntington, West Virginia. Following his father's death when Marshall was a teenager, he moved to New York City to be with his mother, a costume designer.
View Resume | Official Photos Â». Winston Marshall was born on February 26, 1983 in Scarborough, Ontario, Canada as Winston George Marshall Jr. He is an actor, known for Change of Plans (2011), Nikita (2010) and Covert Affairs (2010). See full bio Â».