True Vacc High Vacuum Pumps TVBD/TVBS Series consist of main causing with a rotor fitted eccentrically in it. The vanes are fitted in the slots of rotor on opposite sides with springs between During rotation, the vans move in and out of the slots and sweeps the air space two times in a revolution.True Vacc Pump’s Belt Driven Rotary Vane Vacuum Pumps feature micron range ultimate vacuum, reliable operation best proven performers in industrial and laboratory applications where dependable performance, small footprint, and quiet operation are essential. These pumps feature a Single Stage/Two-stage design and come standard with NW type inlet and outlet connections. Compound stage design and adjustable gas ballast enable these pumps to operate at low noise levels.