Aircraft Hydraulic System Components: Cylinders, Fittings, Pumps, Valves, and Lines
HGW Hydraulics on Jul 8th 2026
Aircraft hydraulic systems use the same basic hydraulic principles found in industrial and mobile equipment, but the design requirements are stricter. Weight, redundancy, pressure, temperature, safety, maintenance access, and component certification all affect the final system layout.
Actuating Cylinders
Actuating cylinders convert hydraulic pressure into mechanical movement. In aircraft, they may move flaps, landing gear, brakes, doors, steering systems, or other controlled assemblies. The cylinder, seals, fittings, and lines must all handle the required pressure and movement cycle.
Fittings, Hose, Pipe, and Tubing
Fittings connect hoses, tubes, pipes, valves, pumps, actuators, and service points. In aircraft-related systems, fitting type, thread standard, sealing method, orifice size, pressure rating, and material compatibility are tightly controlled. Hose, pipe, and tubing carry hydraulic fluid from the pump to valves, actuators, motors, and return circuits.
Pumps, Reservoirs, and Heat Control
The pump pressurizes the system. The reservoir stores hydraulic fluid and allows the system to supply, return, and condition fluid as needed. Heat exchangers help manage fluid temperature so viscosity, seal behavior, and component life stay within the required operating range.
Pressure Relief and Control Valves
Pressure relief valves protect the system from over-pressurization. Other control valves direct flow, regulate movement, isolate circuits, or support backup functions. Because aircraft systems may require redundancy, the valve and line layout can be more complex than a simple industrial hydraulic circuit.
Seals and Material Compatibility
Seals must match the hydraulic fluid, temperature range, pressure, and component movement. PTFE and other engineered seal materials are often selected where temperature and chemical compatibility are important. A reliable hydraulic system depends on every component, from the pump to the smallest seal, matching the service requirements.