AN fittings play a crucial role in fluid systems, ensuring secure and leak-free connections. These fittings are widely used in automotive, aerospace, and hydraulic applications, where precision and reliability are essential.
One key aspect of AN fittings is the flare angle, which directly affects how well the connection seals and prevents leaks. Understanding the AN flare angle is important for selecting the right fittings and avoiding compatibility issues.
This guide provides a quick and easy overview of AN flare angles, helping you understand their significance and how to correctly identify and use them.
Understanding the AN Flare Angle
The AN (Army-Navy) flare angle refers to the specific angle at which the tubing or fitting is flared to create a tight seal when connected. This design ensures a reliable and secure connection that withstands high pressures.
Standard AN Flare Angle (37°) vs. Other Common Flare Angles
➡️ The standard AN flare angle is 37°, meaning the flare surface is angled at 37 degrees.
➡️ Another common flare angle is 45°, used in SAE (Society of Automotive Engineers) fittings.
Why the 37° Flare Angle Is Standard in Aviation, Automotive, and Hydraulic Systems
➡️ The 37° flare angle was established by the military for high-pressure and high-performance applications.
➡️ It provides a superior seal and is less prone to deformation under stress compared to other flare angles.
➡️ AN fittings are commonly used in fuel, oil, and hydraulic lines where reliability is critical.
AN Flare Angle vs. Other Flare Types
Comparison of AN vs. SAE 45° Flare Fittings
➡️ AN Fittings (37° Flare): Used in high-performance applications like aviation, motorsports, and hydraulic systems.
➡️ SAE Fittings (45° Flare): Common in plumbing and lower-pressure automotive systems.
Why Mixing Different Flare Angles Can Cause Leaks or Fitting Failures
➡️ A 37° AN fitting and a 45° SAE fitting will not seal properly when connected, leading to potential fluid leaks and pressure loss.
➡️ Mixing different flare angles can cause deformation or damage to the fitting surfaces.
How to Correctly Identify an AN Fitting Based on Flare Angle
➡️ Look for markings or manufacturer specifications.
➡️ Use a flare gauge or protractor to measure the angle.
➡️ Compare fittings visually to ensure compatibility.
Applications of AN Flare Fittings
Common Industries Using AN Flare Fittings
➡️ Automotive: Used in fuel and brake lines for race cars and performance vehicles.
➡️ Aerospace: Found in aircraft hydraulic and fuel systems due to high reliability.
➡️ Racing: Essential for fluid transfer in high-performance racing applications.
➡️ Hydraulics: Used in industrial hydraulic systems requiring leak-proof connections.
Benefits of AN Fittings
➡️ Durability: Made from high-strength materials like aluminum and stainless steel.
➡️ Leak Resistance: The precise 37° flare ensures a secure and reliable seal.
➡️ Ease of Installation: Can be easily assembled and disassembled without special tools.
Measuring and Identifying AN Flare Angle
Tools for Measuring Flare Angles
➡️ Protractor: Measures the angle of the flare.
➡️ Flare Gauge: Specifically designed to check fitting angles.
Steps to Check If a Fitting Has a 37° AN Flare
1. Clean the fitting surface to remove dirt and debris.
2. Use a protractor or flare gauge to measure the angle.
3. Compare with a known AN fitting to confirm the angle.
Visual Guide to Distinguishing Between 37° and 45° Flares
➡️ A 37° flare has a slightly shallower angle than a 45° flare.
➡️ Placing a 37° and 45° fitting side by side can help in visual identification.
Common Mistakes and Troubleshooting
Mixing AN Fittings with Incompatible Flare Angles
➡️ Always check the flare angle before connecting fittings.
➡️ Avoid using adapters unless specifically designed for cross-compatibility.
Over-Tightening or Under-Tightening Flare Fittings
➡️ Over-tightening can distort the flare and damage the fitting.
➡️ Under-tightening can lead to leaks and pressure loss.
➡️ Follow manufacturer torque specifications for proper installation.
Signs of Improper Sealing and How to Fix Leaks
➡️ Leaks at the flare joint: Check for improper alignment or damage.
➡️ Cracks or deformations: Replace the fitting if any damage is visible.
➡️ Persistent leaks: Ensure you are using the correct flare angle.
Conclusion
Key points about AN flare angles:
➡️ AN fittings use a 37° flare angle, different from the SAE 45° flare.
➡️ Mixing flare angles can cause leaks and fitting failures.
➡️ AN flare fittings are widely used in automotive, aerospace, racing, and hydraulic systems.
Importance of using the correct Flare angle for safe and efficient connections:
➡️ Using the right flare angle ensures a leak-free and durable connection.
➡️ Always verify the flare angle before installation.
Final tips for selecting and installing AN Flare fittings:
➡️ Measure before installation to avoid compatibility issues.
➡️ Use high-quality fittings to prevent failure under pressure.
➡️ Follow manufacturer guidelines for proper tightening and maintenance.
By understanding AN flare angles, you can ensure safe, secure, and efficient fluid connections for your specific application.
Post time: Apr-22-2025