The MS28778-12 is an aerospace-standard O-ring sealing element (packing) used in aircraft hydraulic, fuel, pneumatic, and lubrication systems. It provides a reliable pressure-tight seal between mating components such as fittings, valves, pumps, and actuator housings.

This seal is designed to maintain performance under high pressure, vibration, and wide temperature variations typical in aviation service conditions. It is suitable for both static sealing applications and light dynamic sealing points depending on system design.

Manufactured to MS specifications, it is typically made from FKM (Viton-type) or equivalent aerospace-grade elastomer, offering strong resistance to aviation fluids, hydraulic oils, fuels, and environmental aging.

Key features include:

MS28778-12 aerospace O-ring packing
Used in hydraulic, fuel, and pneumatic systems
Provides leak-proof pressure sealing
Resistant to aviation fluids and oils
High temperature and pressure capability
Suitable for vibration and cyclic loads
FKM (Viton-type) elastomer construction
Used in fittings, valves, pumps, and actuators
Standard MS aircraft sealing component
Direct replacement per MS aerospace hardware standards