The VARIOspeed® VFD is designed specifically for pressure control applications.  As the flow and head conditions change in the pumping system, the VARIOspeed® VFD is able to automatically control the pump speed and maintain a constant discharge pressure. The unit is available from 5 to 150 hp at 208 to 240V and 5 to 250 hp at 80to 480V, single phase or three-phase supply voltage.