Hydraulic systems turn pressured oil into mechanical energy, allowing them to be more efficient than other engine types. Fluid is moved through the system via hydraulic pumps, which are controlled by valves. Filtration systems keep hydraulic fluid pure by removing water and air. Seals keep fluid in and impurities out of the system, ensuring that it operates smoothly. Lifts, fans, and other equipment are powered by hydraulic motors, which convert hydraulic energy to rotary energy.