M83248/1-009 - Preformed High Temperature Packing Seal O-Ring

M83248/1-009 – Mil-Spec Fluorosilicone O-Ring

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Overview

The M83248/1-009 is a military-specification, preformed packing (O-ring) manufactured in strict accordance with MIL-DTL-83248/1. This standard is critical, as it mandates a Fluorosilicone (FVMQ) elastomer, a material specifically engineered to provide an exceptionally wide operational temperature range for aerospace fluid systems. The defining characteristic of this O-ring is its outstanding flexibility at extremely low temperatures, a condition where many other elastomers can become rigid and fail to maintain a seal.

With its AS568-009 size and 75-durometer hardness, this O-ring is designed for general-purpose static sealing in connectors, valves, and component housings. The FVMQ material provides excellent resistance to aviation gasoline, jet fuel, and petroleum-based oils while maintaining its physical properties from the cold-soak conditions of high altitude flight to the elevated temperatures near the engine compartment. For any application demanding a reliable seal across extreme temperature swings, the fully certified and traceable M83248/1-009 O-ring is the required engineering solution.

Key Features

• Mil-Spec Certified: Manufactured and tested in strict accordance with MIL-DTL-83248/1, guaranteeing material composition, dimensional accuracy, and performance in extreme temperatures.

• Fluorosilicone (FVMQ) Material: A specialized elastomer that combines the excellent fuel and oil resistance of fluorocarbons with the superior low-temperature flexibility of silicones.

• Extreme Operational Temperature Range: Engineered to maintain a positive seal in temperatures ranging from approximately -85°F to 400°F (-65°C to 204°C).

• 75 Durometer Hardness: A medium hardness (Shore A) that provides an excellent balance of sealing force and conformability for general-purpose static applications.

• Excellent Fuel & Oil Resistance: Highly resistant to swelling, hardening, or degradation when in contact with hydrocarbon fuels and petroleum-based lubricating oils and hydraulic fluids.

Technical Specifications

• Part Number / Specification: M83248/1-009

• Component Type: O-Ring / Preformed Packing

• OEM Manufacturer: Certified Mil-Spec Manufacturer

• Material: Fluorosilicone (FVMQ), 75 Durometer (Shore A)

• Size Standard: AS568 Dash Number -009 (Nominal Dimensions: 7/32" ID, 1/16" Cross-Section).

• Governing Specification: MIL-DTL-83248/1.

• Typical Operating Temperature Range: -85°F to 400°F (-65°C to 204°C).

Aircraft Compatibility

• Universal Aerospace Application: This is a standard mil-spec O-ring used on a vast range of aircraft where a seal with these specifications is required by the engineering drawings or maintenance manual. It is found on aircraft manufactured by:

  • Textron Aviation (Cessna, Beechcraft), Boeing, Lockheed Martin, Bombardier, Piper, Gulfstream, and others.

Note: The correct O-ring material and part number must be verified in the specific aircraft or component maintenance manual. Elastomer selection is flight-critical and system-dependent.

Applications

• Fuel Systems: Provides static seals for fuel selector valves, drain valves, fuel quantity transmitters, and line connectors that are exposed to wide temperature variations.

• Engine & Propeller Systems: Used in engine accessories, propeller governors, and oil system components where both heat and extreme cold are factors.

• Hydraulic Systems: Suitable for petroleum-based (e.g., MIL-PRF-5606) hydraulic systems requiring a low-temperature seal. Not for use with phosphate-ester fluids like Skydrol.

Why Choose M83248/1-009?

Choosing the correct elastomer for an aerospace application is a critical safety decision. The M83248/1-009 is specified for locations where an ordinary Nitrile (Buna-N) or even a standard Fluorocarbon (FKM) O-ring would fail due to low-temperature embrittlement. Substituting a less capable seal will inevitably lead to a fluid leak during a cold-soak at altitude. Such a leak, whether fuel or oil, presents a catastrophic fire hazard and a risk of engine failure. The certified M83248/1-009 is a low-cost, engineered component that guarantees the specific material properties required to maintain a safe and reliable seal across the full flight envelope.

The unique performance of the M83248/1-009 O-ring is a direct result of the molecular architecture of Fluorosilicone (FVMQ). This elastomer is engineered by incorporating trifluoropropyl groups onto the siloxane backbone of a silicone polymer. The siloxane (silicon-oxygen) backbone is what gives the material its outstanding thermal stability and extremely low glass transition temperature (Tg), allowing it to remain flexible and resilient at temperatures far below the brittle point of hydrocarbon-based rubbers. The pendant fluorine groups, which are highly electronegative, create a polar molecule that is chemically resistant to non-polar hydrocarbon fuels and oils, preventing swelling and degradation. This molecular hybridization creates a material that uniquely combines the extreme temperature range of a silicone with the fluid resistance of a fluorocarbon, making it the ideal engineering solution for static seals in aerospace fluid systems that must perform from -85°F to 400°F.

Note: The M83248/1-009 is a flight-critical seal. Never reuse O-rings. Always install a new, certified O-ring whenever a fitting is disconnected. Inspect the sealing surfaces for any nicks, scratches, or corrosion before installation. Lightly lubricate the new O-ring with clean system fluid to prevent damage during installation. Ensure the O-ring is not twisted in the gland.

Documentation

• MIL-DTL-83248/1: The military detail specification sheet defines all material, dimensional, and testing requirements for this O-ring and is publicly available through the Defense Logistics Agency ASSIST database and various online mil-spec libraries.