Reversing pumps are used when hydraulic steering is fitted on boats (typically powerboats) up to 65 feet L.O.A. (depending on rudder torque). The pumps are switched on by the automatic pilot and make a steering correction to left or right determined by the direction of rotation of the pump motor. The motors are of the permanent magnetic type and reversing direction is accomplished by reversing the motor input current.
The pump has only three moving parts and requires no complicated check valves to prevent rudder movement when de-energized. Output flow is completely adjustable to 50% of rated flow allowing the pump output to be adjusted precisely to the volume of steering cylinder fitted. The pump is exceptionally reliable and delivers more than twice the hydraulic output per watt of input than gear pumps manufactured by competitors.