AS5195W0502 - Textron Aviation OEM CRES Bulkhead Flareless Tube Fitting End

AS5194W0502 – Textron Aviation CRES Bulkhead Flareless Tube Fitting End

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The AS5194W0502 is a high-integrity bulkhead fitting end, manufactured in strict accordance with SAE Aerospace Standard AS5194. Specified by Textron Aviation and utilized across the aerospace industry, this component provides a secure, leak-free connection point for 5/16-inch flareless (MS-style) tubing passing through a structural bulkhead or panel. Its design allows for the robust transmission of fluids—hydraulic oil, fuel, pneumatic air, or oxygen—while maintaining the structural integrity of the partition it penetrates.

This fitting is precision-machined from Corrosion-Resistant Steel (CRES), likely a 300-series alloy, designated by the "W" in the part number. CRES offers superior strength, corrosion resistance, and temperature tolerance compared to aluminum, making it suitable for demanding high-pressure (3000 PSI) applications, including those involving aggressive fluids or elevated temperatures. The flareless design utilizes a compressive ferrule or sleeve (sold separately) to achieve a high-pressure seal directly onto the outside diameter of the tubing. The fitting is typically passivated for enhanced corrosion resistance.

Key Features

• SAE Aerospace Standard (AS) Certified: Manufactured to the exact material, dimensional, and performance tolerances of AS5194.

• Flareless Tube Connection (MS Style): Creates a high-pressure seal using a compressive sleeve/ferrule system (e.g., MS21921 sleeve), eliminating the need for tube flaring.

• Bulkhead Mounting Design: Features an integrated shoulder and locknut threads for secure mounting through an airframe structure or panel.

• Corrosion-Resistant Steel (CRES) Construction: Provides superior strength, durability, and resistance to corrosion and high temperatures compared to aluminum fittings.

• Passivated Finish: Enhances the natural corrosion resistance of the stainless steel alloy.

• 3000 PSI Pressure Rating: Suitable for high-pressure hydraulic, fuel, oxygen, and pneumatic system applications.

Technical Specifications

• Part Number: AS5194W0502

• Component Type: Bulkhead Fitting End, Flareless Tube Connection, Straight

• Governing Specification: AS5194

• OEM Applicability: Textron Aviation (Cessna, Beechcraft), and all other manufacturers utilizing AS/MS standard flareless fittings.

• Material: Corrosion-Resistant Steel (CRES), likely 300 Series Stainless Steel.

• Finish: Passivated per AMS 2700 or similar standard.

• Tube Size: For 5/16 inch OD tubing (MS size -5).

• Thread Size (Tube End): 1/2-20 UNF-3A (for MS flareless nut).

• Nominal Working Pressure: 3000 PSI.

Aircraft Compatibility

The AS5194W0502 is a standard hardware component utilized in the fluid systems of numerous aircraft where 5/16-inch CRES flareless tubing must pass through a bulkhead. It is commonly found on Textron Aviation platforms (including Citation jets) and other aircraft employing MS-style flareless plumbing, especially in high-pressure or high-temperature areas.

Crucial Note: The correct fitting part number, size, and material for a specific application must be verified against the aircraft's Illustrated Parts Catalog (IPC) or maintenance manual.

Applications

• Providing a pass-through connection for 5/16" CRES flareless tubing lines traversing firewalls, pressure bulkheads, wing ribs, or equipment panels.

• Used in high-pressure hydraulic systems (including those using Skydrol®, compatible with CRES).

• Specified for fuel, oil, oxygen (with appropriate cleaning), bleed air, and pneumatic systems where the strength and temperature resistance of CRES are required.

Why Choose AS5194W0502?

Choosing a genuine, certified AS5194W0502 fitting is essential for ensuring the integrity of high-pressure fluid systems. The flareless sealing mechanism relies on extremely precise machining of both the fitting body and the mating sleeve. Using a non-certified part risks improper material strength (especially critical with CRES), incorrect dimensions, or poor surface finishes, any of which can lead to a catastrophic leak or fitting failure under pressure. The AS standard guarantees the fitting meets the rigorous requirements for material traceability, manufacturing quality, and pressure testing demanded for flight safety. The CRES material offers superior performance over aluminum in many demanding applications.

The sealing mechanism of the AS5194W0502 flareless fitting relies on the principle of controlled metal deformation. Unlike a flared fitting which seals on a conical surface, the flareless system uses a separate sleeve or ferrule (e.g., MS21921). During assembly, the MS nut (e.g., MS21900) pushes this hardened sleeve axially forward along the tubing. The internal geometry of the AS5194 fitting body features a precisely angled seat that forces the leading edge of the sleeve to radially contract and bite into the outer diameter of the tubing. This action creates a primary, high-pressure, metal-to-metal seal. Simultaneously, the aft end of the sleeve bows slightly, creating a secondary sealing point and also providing significant resistance to vibrational fatigue by supporting the tube just beyond the primary bite. The use of Corrosion-Resistant Steel (CRES) for the fitting body provides a harder, more durable seat compared to aluminum, ensuring reliable sealing performance even after repeated assembly cycles, and offers superior compatibility with aggressive fluids and higher operating temperatures.

Note: This is a flight-critical, high-pressure fluid system component. Proper tube preparation (clean, square cut, free of burrs and scratches) and the use of the correct MS-standard sleeve (material must match tube material) are absolutely essential for achieving a reliable seal. The nut must be tightened to the specific torque value or "turns from finger tight" method specified in standard maintenance practices (e.g., AC 43.13-1B) to ensure the sleeve bites correctly without damaging the tube. Over-tightening can be as detrimental as under-tightening. Installation must be performed by a certified A&P mechanic.

Documentation

The definitive technical requirements for this component are detailed in SAE Aerospace Standard AS5194. These proprietary documents must be sourced directly from the relevant standards organizations for complete engineering specifications.