Hydraulic Power Units - What Are They and What Are They Used For? The hydraulic power unit (HPU) is used in a number of different applications. It can provide access to fluid power in a mobile or static environment. The HPU comprises of several components that work together to produce and utilise hydraulic energy. Most often you will find: · Cylinders that will perform the conversion of hydraulic power to either rotary mechanical or linear power. · A pump to convert mechanical power into hydraulic power · Reservoir. The storage of fluid. · Valves. These enable the amount, pressure and direction of the fluid. · Filters. Maintenance of the fluid to keep it in performing condition. · Fittings, tubes and hoses. Every user of a hydraulic power unit can be assured of: · Safety · Cost efficiency · Durable reliability · Effective transition of power · A design that enables use with a broad range of different applications with small dimensions. Applications include cranes, loaders, backhoes, amusement rides, car lifting devices, compactors for rubbish collectors and more. Hydraulic power packs are even used as part of the Jaws of Life tools that accident rescue workers are equipped with for use in road and other emergencies. Other mobile applications include diggers, graders, fork lift road maintenance vehicles, agricultural machinery and excavators. You may also find them in industrial use such as assembly equipment, food processing machinery, tools, mining and steel works. Other industries that make use of HPUs include civil engineering, theatres, aerospace, and medicine, marine and automotive. Where else are hydraulic power systems used? You may have heard your mechanic tell you that he has to bleed the brakes. This is because the brakes on many cars use the hydraulic power system to power the brakes. Bleeding the brakes will result in the removal of air bubbles from the brake lines. Just as with larger hydraulic systems, air in the system will prevent the piston(s) from operating properly. In the case of your brakes, it could stop them from working when you need them most. It’s also important not to have a leak in the hose as the pressure will not be enough to be able to slow down your car. The fluid used in a hydraulic power pack is typically made up of a blend of petroleum oil, water and glycol. The type of oil used will depend on what type of application it is being used for. Filters are used to clean dirt, contaminants and foreign particles from the fluid. Excess fluid is stored in a reservoir that can separate the air from it. It’s this cleaning process that enables the machine to perform efficiently. All hoses, tubes and other components need to be able to withstand the pressure within the system.