MS28775-218 - Military Standard O-Ring

MS28775-218 – Military Standard O-Ring

Overview

The MS28775-218 is a high-performance O-ring designed to meet military specifications for aerospace, hydraulic, and fuel system sealing applications. Engineered from acrylonitrile butadiene rubber (NBR), commonly known as Buna-N, this O-ring provides exceptional resistance to petroleum-based hydraulic fluids, ensuring long-lasting reliability in demanding environments.

With its precision-molded construction and compliance with military sealing standards, the MS28775-218 is a critical component in maintaining system integrity and preventing leaks under extreme pressures and temperatures.

Key Features

• Military-Grade Sealing Performance:
  • Manufactured to stringent military standards for aerospace and defense applications.
  • Ensures consistent and reliable sealing in critical aircraft systems.
• Material Composition – Acrylonitrile Butadiene Rubber (Buna-N):
  • Resistant to petroleum-based hydraulic fluids, lubricants, and aviation fuels.
  • Offers high tensile strength and durability in extreme conditions.
• Temperature & Pressure Resistance:
  • Operates effectively in a temperature range of -65°F to 275°F (-54°C to 135°C).
  • Maintains sealing integrity under high-pressure hydraulic and fuel systems.
• Precision-Molded Design:
  • Provides a tight, leak-free fit for hydraulic fittings, valves, actuators, and fuel system components.
  • Engineered for high-wear resistance, reducing maintenance and replacement frequency.

Technical Specifications

• Part Number: MS28775-218
• Material: Acrylonitrile Butadiene Rubber (Buna-N)
• Durometer Hardness: 70 Shore A
• Inside Diameter (ID): 1.234 inches
• Outside Diameter (OD): 1.512 inches
• Cross-Sectional Thickness: 0.139 inches
• Temperature Rating: -65°F to 275°F (-54°C to 135°C)
• Fluid Compatibility: MIL-H-5606 hydraulic fluid and other petroleum-based lubricants

Aircraft Compatibility & Applications

The MS28775-218 O-ring is widely used in aerospace, military, and industrial sealing applications, ensuring leak-proof operation in hydraulic and fuel systems. This O-ring plays a vital role in aircraft maintenance, repair, and overhaul (MRO), preventing fluid loss and maintaining pressure stability.

Common Applications Include:

• Hydraulic System Seals: Prevents leakage and pressure loss in high-performance aircraft hydraulic systems.
• Pneumatic System Seals: Provides airtight seals in pressurized pneumatic components and actuators.
• Fuel System Seals: Compatible with aviation fuel lines, pumps, and connectors for optimal performance.
• Landing Gear & Brake Systems: Ensures tight sealing in hydraulic braking and shock absorption mechanisms.

Why Choose the MS28775-218 Military Standard O-Ring?

The MS28775-218 meets military-grade durability and performance standards, ensuring maximum reliability in mission-critical applications. With superior resistance to fuels, hydraulic fluids, and extreme temperatures, this O-ring provides long-lasting sealing performance while minimizing maintenance and downtime.

Installation & Maintenance Considerations

• Lubrication Requirements: Use a compatible aviation-approved lubricant for proper installation and enhanced longevity.
• Regular Inspection: Periodically check for signs of wear, swelling, or degradation to ensure continued performance.
• Replacement Intervals: Replace as part of scheduled maintenance to prevent hydraulic or fuel system failures.

Note: Always refer to official aircraft documentation and consult certified aviation professionals for installation and maintenance procedures.