Gear pumps transfer highly viscous and harsh liquids such as oils, chemicals, and solvents. They produce constant, smooth flow rates at high pressures. Gear pumps are self-priming and require an initial prime before first use to move liquids from sources below the pump. Electric-operated gear pumps are energy-efficient. Pedestal-mount gear pumps have an exposed drive shaft for coupling a motor with a belt or pulley and should not be directly driven by a motor. Gear pump heads are directly driven by a motor of a compatible horsepower (HP) rating and frame. They do not include a motor.