Gear pump heads are directly driven by motors of compatible horsepower (HP) ratings and motor frames. They do not include a motor. Gear pumps transfer viscous and harsh liquids such as oils, chemicals, and solvents. They produce constant, smooth flow rates at high pressures and have minimal moving parts, making maintenance easy. Gear pumps are self-priming and require an initial prime to create a proper seal and draw liquids from sources below the pump's inlet.