Vacuum forming, also known as thermoforming, requires rapid evacuation to a deep vacuum while the plastic sheeting is still hot. Too slow of an evacuation will result in improper corner formation. To keep the equipment costs to a minimum, this is accomplished by using a vacuum balancing tank with automatic valves and a properly sized vacuum system, based on cycle times. Wintek has supplied many systems on thermoforming, both dedicated vacuum pumps and central vacuum systems. Pumps are typically either rotary vane or oil sealed liquid ring vacuum pumps.