Pic. 2.60. VAD check valve: 1 - check valve; 2 - green; 3 - white; 4 - intake manifold; 5 - vacuum chamber of the VAD system
check valve (unidirectional) maintains a vacuum in the vacuum chamber of the VAD system. The check valve only allows air to flow from the VAD vacuum chamber to the intake manifold (pic. 2.60).