MS28775-141 - Military Standard Aerospace O-Ring

MS28775-141 – Military Standard Aerospace O-Ring

Available now on the Airparts.aero Marketplace.

Overview

The MS28775-141 is a high-performance O-ring manufactured in strict accordance with U.S. Military Standard specifications for use in critical aerospace and defense applications. This specific part number designates a precision-molded seal made from a Fluorocarbon (FKM) elastomer, commonly known by the trade name Viton®. It is engineered to provide exceptional sealing integrity in systems exposed to petroleum-based oils, hydraulic fluids, jet fuels, and high temperatures. As a certified Mil-Spec component, the MS28775-141 guarantees material purity, dimensional accuracy, and performance characteristics required for the most demanding aviation environments.

Key Features

• Superior Chemical Resistance: Made from a Fluorocarbon (FKM) compound, which offers excellent resistance to degradation from a wide spectrum of aviation fluids, including jet fuel (JP-4, JP-5, JP-8), hydraulic fluids (MIL-H-5606), engine oils, and solvents.
• High-Temperature Performance: Engineered to maintain its sealing properties and physical integrity in continuous operating temperatures up to 400°F (204°C), making it ideal for use in engine compartments and hydraulic systems.
• Mil-Spec Certified Quality: Manufactured and inspected under the rigorous quality control protocols of the MS28775 standard. This ensures every O-ring meets the required material composition, durometer, and dimensional tolerances for reliable performance.
• Low Compression Set: Exhibits excellent resistance to permanent deformation under compression, ensuring a reliable, long-term seal even after prolonged periods of being static or subjected to pressure cycles.
• Precise Dimensions: The "-141" dash number corresponds to a specific and tightly controlled dimensional standard, guaranteeing a perfect fit in glands and grooves designed for this size.

Technical Specifications

• Standard: MS28775
• Dash Size: -141
• Material: Fluorocarbon Elastomer (FKM, Viton®)
• Durometer (Hardness): 75 Shore A
• Nominal Dimensions:
  • Inside Diameter (I.D.): 2.234 inches
  • Outside Diameter (O.D.): 2.514 inches
  • Cross Section (C.S.): 0.140 inches
• Color: Black
• Operating Temperature Range: -15°F to 400°F (-26°C to 204°C)
• Shelf Life: Conforms to aerospace standard shelf life requirements (typically 10+ years under proper storage conditions)

Aircraft Compatibility

The MS28775-141 is not specific to a single aircraft model but is specified by engineers for use in any system requiring a seal with its specific dimensions and material properties. It is found throughout virtually all types of military and commercial aircraft.

• Hydraulic Systems: Used in actuators, valves, pumps, and reservoirs.
• Fuel Systems: Seals for fuel line fittings, connectors, fuel pumps, and tank access panels.
• Engine & Powertrain: Utilized in lubrication systems, propeller hubs, and accessory gearbox housings.
• Landing Gear: Critical seals within struts, retraction mechanisms, and braking systems.

Applications

The MS28775-141 is designed for static sealing applications where reliability is paramount:

• Flange Seals: Creating a seal between two flat-faced components.
• Gland Seals: Sealing shafts or pistons within a housing.
• Fluid Line Connections: Used in AN/MS fittings to prevent leaks at connection points.

Why Choose MS28775-141?

In aviation, there is no substitute for certified quality. Choosing a genuine MS28775-141 O-ring ensures you are using a component that has been designed, manufactured, and tested specifically for the extreme conditions of flight. Unlike commercial-grade O-rings, this Mil-Spec part guarantees the precise chemical composition and physical properties needed to prevent catastrophic leaks in fuel, oil, and hydraulic systems. For any A&P mechanic, engineer, or aircraft owner, using certified hardware like the MS28775-141 is a fundamental requirement for ensuring airworthiness and safety.

Order Your MS28775-141 O-Rings Now

Ensure the integrity of your aircraft's critical systems with a genuine MS28775-141 Mil-Spec O-ring. Visit Airparts.aero to order today and secure certified components for your maintenance needs.

The MS28775 military specification defines the technical requirements for a series of packing, preformed, petroleum hydraulic fluid resistant O-rings. The "-141" suffix designates its precise geometry according to the AS568 standard. The selection of a Fluorocarbon (FKM) polymer for this standard is deliberate; its molecular structure provides high thermal stability and chemical inertness to aliphatic and aromatic hydrocarbons, making it the default material for sealing systems containing jet fuel and petroleum-based hydraulic fluids. The 75 durometer hardness represents an optimal balance between pliability for effective sealing at low pressures and extrusion resistance for reliability at high pressures. When a maintenance manual or engineering drawing calls for an MS28775-141, it signifies that the connection's safety and reliability are contingent upon the unique combination of these material properties and dimensional controls.

Note: Always verify the correct part number required for your specific application from the relevant maintenance or overhaul manual. Ensure O-rings are within their specified shelf life before installation. Lubricate with a compatible fluid (e.g., system fluid) before installation to prevent damage.

MS28775-141 Part Specifications:

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