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.
George C. Marshall Jr. was born on December 31, 1880, in Uniontown, Pennsylvania. A graduate of the Virginia Military Institute, he served in both world wars, rising to the post of U.S. Army chief of staff.After the war, he served as the secretary of state and crafted the Marshall Plan for European recovery.uring his military career, George C. Marshall Jr. served as U.S. Army chief of staff and secretary of state. He was awarded the Nobel Peace Prize in 1953.