AS3209-123 - Aerospace Preformed Packing Seal O-Ring

AS3209-123 – Aerospace Preformed Packing Seal O-Ring

Available now on the Airparts.aero Marketplace.

Overview

The AS3209-123 is a certified aerospace-grade O-ring manufactured to the stringent SAE Aerospace Standard AS3209. This preformed packing seal is engineered specifically for reliable service in aircraft hydraulic systems that operate with MIL-H-5606 petroleum-based hydraulic fluid. The AS3209 standard requires a specialized Nitrile (Buna-N) rubber compound, formulated to provide superior resistance to hydraulic fluids and excellent physical durability for both static and dynamic sealing applications. As a certified aerospace component, the AS3209-123 is a flight-critical seal for ensuring the leak-free operation of landing gear, brakes, and flight control systems.

Key Features

• Hydraulic Fluid Compatibility: Fabricated from a high-quality Nitrile (Buna-N) rubber compound specifically formulated to resist swelling, hardening, and degradation when in constant contact with MIL-H-5606 red hydraulic oil.
• Excellent Physical Properties: Offers high tensile strength and superior resistance to abrasion, making it an ideal material for dynamic seals that move against metal surfaces, such as in hydraulic actuators.
• Aerospace Standard Certification: Manufactured and certified to the AS3209 specification, which governs the material compound, dimensional tolerances, and physical properties, ensuring a dependable and airworthy component.
• Precision Dimensions: The "-123" dash number corresponds to the AS568 universal standard, guaranteeing a precise fit in glands and grooves designed for this O-ring size, which is essential for proper sealing performance under pressure.
• High-Reliability Sealing: Provides a dependable seal in a wide range of pressures typical in general aviation hydraulic systems.

Technical Specifications

• Standard: SAE AS3209 (Packing, Preformed, Petroleum Hydraulic Fluid Resistant, 75 Durometer)
• Full Part Number: AS3209-123
• Material: Nitrile Rubber Compound (Buna-N, NBR)
• Durometer (Hardness): 75 Shore A
• Color: Black
• AS568 Dash Size: -123
• Nominal Dimensions:
  • Inside Diameter (I.D.): 1.171 inches
  • Cross Section (C.S.): 0.116 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 AS3209-123 O-ring is a standard hydraulic seal used throughout the aviation industry, including numerous Textron Aviation (Cessna, Beechcraft), Piper, and other aircraft platforms. Its use is dictated by the design of the specific hydraulic component in which it is installed.

• Common Applications:
  • Landing Gear Actuators & Struts: Serving as piston seals, gland seals, and static seals in the landing gear hydraulic system.
  • Hydraulic Brakes: Used as seals within brake master cylinders and piston calipers.
  • Flight Control Systems: Utilized in hydraulic actuators for flaps and other hydraulically-assisted flight controls.
  • Hydraulic Fittings & Valves: Provides the primary seal in various hydraulic line connections and valve assemblies.

Applications

The AS3209-123 is the specified sealing solution for numerous hydraulic system requirements:

• Dynamic Piston & Rod Sealing: Creates a reliable, high-pressure seal for moving components within hydraulic actuators.
• Static Flange & Face Sealing: Used to provide a leak-proof seal between stationary hydraulic components.
• Hydraulic Component Overhaul: A mandatory replacement item whenever a hydraulic component is disassembled for inspection, repair, or overhaul.

Why Choose AS3209-123?

The failure of a single hydraulic O-ring can lead to the failure of an entire system, such as landing gear extension or braking. The integrity of these seals is therefore paramount. By choosing a genuine AS3209-123 O-ring, you are guaranteeing that the seal is made from the specific Nitrile compound tested and certified for long-term compatibility with MIL-H-5606 fluid. The use of non-certified O-rings made from incorrect materials can lead to rapid deterioration, leaks, and system failure. For any hydraulic system maintenance, trust only certified aerospace-grade seals.

Order Your AS3209-123 O-Rings Now

Maintain the integrity and reliability of your aircraft's hydraulic systems with certified AS-standard seals. Visit Airparts.aero to order your AS3209-123 O-rings today.

The AS3209 standard for preformed packing is a cornerstone of hydraulic system design in aviation. The specified 75-durometer Nitrile compound provides an optimal balance of physical properties. It is soft enough to conform to microscopic imperfections in gland surfaces to prevent leaks at low pressure, yet hard enough to resist extrusion into the clearance gap when subjected to high system pressures (up to 1,500 PSI or more when used with backup rings). Its excellent abrasion resistance allows it to survive millions of cycles in dynamic applications. The "-123" designation from the AS568 dimensional standard dictates the precise geometry needed to ensure the O-ring is properly "squeezed" upon installation, creating the initial sealing force that is then energized by system pressure for a positive, leak-free 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.