Stilson Vac-Lok Vacuum Generator and Lock: The Vac-Lok Venturi provides added safety for vacuum material handling systems. Once it creates a vacuum, it automatically seals and holds until you release it. It’s a necessity on applications where air supply lines must be disconnected for long periods of time or have the potential of being accidentally cut. The result is less damage to work pieces. Vac-Lok operates on the same principle as a standard Venturi with the addition of two ball check valves. Pressurized air is introduced through the air-in port. It passes through a small opening, drawing air up through the vacuum port, thereby creating the vacuum for lifting and holding parts. This flow of air through the vacuum port lifts the ball check off its seat until the required vacuum is reached. At this time, the spring loaded ball seats and seals the vacuum. The pressurized air flow is discharged through the external port, which is threaded to accept a Stilson silencer. An additional port is provided for gauging and sensing the amount of vacuum on applications where cups must hold for long periods of time without a constant air supply, or as an extra vacuum port for operating other cups. The second ball check is located in the vacuum release port. The vacuum may be released by two methods. One method is introducing air into the vacuum release port. The other method is the use of a manual release button. Both methods open the check valve.