AS3209-129 - Textron Aviation OEM Preformed Packing O-Ring

AS3209-129 – Textron OEM Preformed Packing O-Ring

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Overview

The AS3209-129 is a high-performance, preformed packing O-ring manufactured in strict accordance with SAE Aerospace Standard AS3209. This component is specifically engineered for use in demanding aerospace hydraulic systems, particularly those utilizing MIL-H-5606 (mineral base) hydraulic fluid. The AS3209 standard mandates a specialized Nitrile (Buna-N) rubber compound that is formulated for an excellent combination of fluid resistance, abrasion resistance, and durability across a moderate temperature range. As a certified aerospace-grade seal specified by Textron Aviation, the AS3209-129 is a flight-critical component for ensuring the leak-free integrity of hydraulic actuators, valves, and fittings.

Key Features

• Hydraulic Fluid Resistance: Fabricated from a specialized Nitrile (Buna-N) compound, providing excellent resistance to swelling, softening, and degradation when exposed to MIL-H-5606 red hydraulic oil.
• High-Durability Compound: Offers superior tensile strength and resistance to abrasion and tearing, making it ideal for use in both static and dynamic hydraulic sealing applications.
• Aerospace Standard Certified: Manufactured and certified to the AS3209 specification, which controls the material compound, physical properties, and dimensional tolerances, ensuring a reliable and airworthy seal.
• Precise Dimensions & Durometer: The "-129" dash number corresponds to a specific dimensional standard (AS568), guaranteeing a perfect fit in hydraulic glands. The specified durometer ensures the correct hardness for effective sealing under pressure.
• Genuine OEM Component: Specified by Textron Aviation for use in their aircraft, guaranteeing the part meets the original performance and quality requirements of the airframe's type certificate.

Technical Specifications

• Standard: SAE AS3209 (Packing, Preformed, Petroleum Hydraulic Fluid Resistant)
• Full Part Number: AS3209-129
• Material: Nitrile Rubber Compound (Buna-N, NBR)
• Durometer (Hardness): 75 Shore A
• Color: Black
• AS568 Dash Size: -129
• Nominal Dimensions:
  • Inside Diameter (I.D.): 1.487 inches
  • Cross Section (C.S.): 0.103 inches
• Primary Fluid Compatibility: MIL-H-5606 Petroleum-Based Hydraulic Fluid
• Operating Temperature Range: Approximately -65°F to 275°F (-54°C to 135°C)

Aircraft Compatibility

The AS3209-129 O-ring is a standard component used in the hydraulic systems of a vast number of aircraft, including many models manufactured by Textron Aviation (Cessna, Beechcraft). Its use is determined by the specific design requirements of the hydraulic component it is installed in.

• Common Applications:
  • Landing Gear Systems: Used as seals in landing gear actuators, shock struts, and retract mechanisms.
  • Brake Systems: Found in brake master cylinders, calipers, and hydraulic lines.
  • Flap & Flight Control Actuation: Utilized in hydraulic actuators for flaps and other flight control systems.
  • Hydraulic Power Packs: Serves as static and dynamic seals within hydraulic pumps and valve bodies.

Applications

The AS3209-129 is the engineered sealing solution for a variety of hydraulic system needs:

• Dynamic Sealing: Designed to create a reliable seal on moving components like hydraulic pistons and actuator rods.
• Static Sealing: Used to seal stationary joints, such as flanges, fittings, and plugs within the hydraulic system.
• Component Overhaul: A mandatory replacement item during the overhaul of any hydraulic component to restore sealing integrity.

Why Choose AS3209-129?

A leak in an aircraft's hydraulic system can lead to a loss of function for critical systems like landing gear and brakes. The integrity of every seal is paramount. Using a genuine AS3209-129 O-ring guarantees that the seal is made from the correct Nitrile compound, specifically formulated and tested for compatibility with MIL-H-5606 hydraulic fluid. Substituting with a non-certified, commercial-grade O-ring can lead to seal failure from material incompatibility, resulting in leaks and potential system failure. For any hydraulic system repair, trust only certified aerospace-grade seals.

Order Your AS3209-129 O-Rings Now

Ensure the leak-free performance and reliability of your aircraft's hydraulic systems with certified AS-standard seals. Visit Airparts.aero to order your AS3209-129 O-rings today.

The AS3209 specification defines O-rings intended for petroleum-based hydraulic service, distinguishing them from other standards like the M25988 (Fluorosilicone for wide temperature/fuel) or M83248 (Fluorocarbon for high temp/synthetic fluids). The Nitrile (Butadiene Acrylonitrile) polymer chemistry of the AS3209-129 provides an excellent balance of properties. Its polar nature makes it highly resistant to non-polar petroleum oils, while its molecular structure provides good physical strength and abrasion resistance, which is essential for seals that move against a cylinder wall. The "-129" dash number from the AS568 universal standard precisely defines the geometry required to fit into a standardized groove, or "gland," ensuring the correct amount of "squeeze" is applied to the O-ring upon installation to create an effective initial seal.

Note: This is a flight-critical sealing component. Always verify the correct O-ring part number from the applicable component maintenance manual (CMM) or aircraft Illustrated Parts Catalog (IPC). Ensure the O-ring is within its specified shelf life before installation. Lubricate with clean system hydraulic fluid (MIL-H-5606) to prevent damage during assembly. Never use tools that could nick or scratch the O-ring or sealing surfaces.

Item Replacement History

• Part Number: AS3085-129 ORING: FLUOROCARBON,75, USE AS3209-129=64
• Part Number: AS3209-129 ORING: FLUOROCARBON,75, USE AS3209-129=64