All maintenance levels use SE. General types of hydraulic SE are portable hydraulic test stands, hydraulic fluid dispensing equipment, and stationary hydraulic test stands.

Portable hydraulic test stands are mobile sources of external hydraulic power. They can be connected to an aircraft hydraulic system to provide power normally obtained from the aircraft hydraulic pumps. The test stands provide a means of energizing the aircrafts hydraulic systems. SE is used on the flight line and in hanger work areas. In addition, portable test stands are important tools for hydraulic con-tamination control. They are the primary means of aircraft hydraulic decontamination. Several types of portable stands are available. Their primary difference is their prime power source (electric motor or engine driven), functional features, and maximum flow capability.

Hydraulic fluid dispensing units are portable. They are used to replenish hydraulic fluid lost or otherwise removed from a system. They provide a means of dispensing new filtered fluid under pressure, in a manner that minimizes the introduction of external contaminants. Several different types of hydraulic fluid dispensing equipment are available.

Stationary hydraulic test stands are permanently installed equipment used for shop-testing hydraulic system components. Except for specialized equip-ment, such as hose burst test stands, they are general-purpose equipment capable of performing a variety of tests on components such as hydraulic pumps, actuators, motors, valves, accumulators, and gauges. Typical component test stands consist of adjustable sources of hydraulic and shaft-driven (for pump drive) power, with associated regulator and indicating devices that let you monitor performance under simulated operating conditions. Stationary hydraulic test stands are used at the intermediate-maintenance level, ashore and afloat, and for depot-level maintenance.