Ball Valve Assembly
The ball valve assembly consists of a chromium ball bearing, tapered return spring, cir-clip and housing body. The return spring holds the ball bearing up flush against the tapered breach in the neck of the housing. This represents the 'closed' position of the valve with no airflow possible. By applying downward pressure on the counter-sprung ball bearing, contact between it and the tapered breach in the housing neck is broken, opening the valve to airflow. When placed in the centre of a vacuum cell of rubberised gasket material downward pressure from the workpiece opens the valve and a vacuum seal is formed holding it securely in place.