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MS29513-219 – Preformed Packing O-Ring
Available now on the Airparts.aero Marketplace.
Overview
The MS29513-219 is a flight-critical, military-standard preformed packing O-ring, an essential sealing component for the fuel systems of a wide range of aircraft. This is not a generic O-ring; it is a precision-molded seal engineered in strict accordance with the MS29513 (MIL-P-5315) specification. The MS29513-219 is fabricated from a high-quality Nitrile (Buna-N) rubber compound, specifically formulated to provide exceptional resistance to hydrocarbon fuels. Its primary function is to create a positive, leak-proof seal in fuel line fittings, filter assemblies, and other fuel system components.
As a genuine military-specification component, it guarantees the correct material performance, dimensional accuracy, and quality control required for a flight-critical fuel system application. Its integrity is fundamental to preventing fuel leaks and ensuring the safe operation of the aircraft.
Key Features
Hydrocarbon Fuel Resistance: Fabricated from a specialized Nitrile (Butadiene-Acrylonitrile, NBR) compound. This material is the industry standard for sealing against hydrocarbon fuels like Jet A and 100LL Avgas, providing superior resistance to swelling, hardening, and degradation.
Reliable Sealing Performance: Designed to provide a durable, positive seal in both static and low-pressure dynamic applications, preventing fuel leakage, which is a critical fire safety requirement.
MS Certified Standard: As a certified Military Standard part, it guarantees the material compound, dimensional tolerances, and physical properties (such as the 70-durometer hardness) meet the stringent requirements for use in certified aircraft.
Wide Temperature Range: Engineered to maintain its sealing integrity and flexibility across a broad temperature range, typically from -65°F to 200°F (-54°C to 93°C).
Precision Dimensions: The "-219" dash number corresponds to a specific dimensional standard (AS568), guaranteeing a perfect fit in glands and grooves designed for this O-ring size.
Technical Specifications
Part Number: MS29513-219
Standard: MS29513 / MIL-P-5315
Component Type: Preformed Packing O-Ring
Material: Nitrile Rubber Compound (Buna-N, NBR)
Durometer (Hardness): 70 Shore A
Color: Black
AS568 Dash Size: -219
Precise Dimensions:
Inside Diameter (I.D.): 1.484 inches
Cross Section (C.S.): 0.139 inches
Primary Fluid Compatibility: Hydrocarbon Fuels (Jet A, Jet A-1, 100LL), Petroleum-Based Oils & Greases.
Certification: Conforms to Military Specification standards.
Aircraft Compatibility
The MS29513-219 is a standard O-ring used in numerous fuel system components across a wide range of business, commercial, and general aviation aircraft. It is imperative to consult the specific aircraft's Illustrated Parts Catalog (IPC) for final verification.
Common Aircraft Platforms:
Bombardier, Textron Aviation, Piper, Embraer, Gulfstream
Common Applications:
Fuel Line Fittings: Used as the primary seal in various types of fuel line connectors and fittings.
Fuel Filter Assemblies: Provides the seal for fuel filter bowls, housings, and bypass valves.
Engine Components: Serves as a seal on fuel pumps, fuel control units, and other engine fuel accessories.
Why Choose MS29513-219?
A fuel leak poses one of the most significant fire and safety risks in aviation. The integrity of every seal in the fuel system is paramount. Using a genuine, certified MS29513-219 O-ring is the only way to ensure the seal is made from the correct Nitrile compound, specifically formulated and tested for long-term compatibility with jet fuels. Substituting with a non-certified or commercial-grade O-ring made from the wrong material (e.g., EPDM) can lead to rapid swelling, softening, and catastrophic failure of the seal.
The MS29513-219 O-ring's Nitrile (Buna-N) material is specified for a precise reason. Nitrile is a co-polymer of butadiene and acrylonitrile. The acrylonitrile content in the polymer chain is what gives the material its excellent resistance to non-polar solvents like jet fuel and petroleum oils. This prevents the O-ring from swelling excessively or breaking down chemically, ensuring it maintains its physical properties and sealing force throughout its entire service life. While less resistant to high temperatures than Fluorocarbon (FKM) seals, the Nitrile specified in MS29513 offers superior low-temperature flexibility, which is a critical performance parameter for seals that may be subjected to the cold-soak conditions of high-altitude flight.
Note: This is a single-use, flight-critical sealing component. It must be replaced whenever the component it seals is removed. Always verify the correct O-ring part number from the applicable aircraft component maintenance manual (CMM) or Illustrated Parts Catalog (IPC). Ensure the O-ring is within its specified shelf life before installation. Lubricate with a clean, compatible system fluid (e.g., jet fuel or approved lubricant) to prevent damage during assembly.
