Flare fitting 101: everything you need to know for seamless connections

A flare fitting is a type of pipe fitting that creates a secure and leak-free connection between two pipes or tubes. It involves flaring the end of a tube outwards, creating a cone-shaped lip. This flared lip is then inserted into a mating fitting, which has a matching cone-shaped surface, and tightened. The result is a metal-to-metal seal that withstands high pressures and prevents fluid leakage.

Types of Flare Fittings

There are various types of flare fittings available, each designed for specific applications:

• Single Flare Fittings: These fittings have a single cone-shaped lip on one end of the tube. They are commonly used in low-pressure applications.
• Double Flare Fittings: These fittings feature two cone-shaped lips on the same end of the tube. They provide a more secure seal and are suitable for higher pressure applications.
• Inverted Flare Fittings: In these fittings, the cone-shaped lip is inverted, facing inward. They are typically used in high-pressure hydraulic systems.
• Compression Flare Fittings: These fittings use a combination of a flared tube and a compression nut to create a seal. They are easy to install and can be used in various applications.

Materials for Flare Fittings

Flare fittings are typically made from the following materials:

• Steel: Durable and corrosion-resistant, suitable for high-pressure applications.
• Stainless Steel: Highly corrosion-resistant, ideal for use in harsh environments.
• Brass: Non-corrosive and easy to machine, suitable for low-pressure applications.
• Aluminum: Lightweight and corrosion-resistant, used in aerospace and automotive industries.

Applications of Flare Fittings

Flare fittings are widely used in various industries, including:

• Hydraulic systems
• Pneumatic systems
• Fuel systems
• Refrigeration systems
• Instrumentation
• Automotive

Advantages of Flare Fittings

• Leak-proof: The metal-to-metal seal ensures a leak-free connection.
• High-pressure resistance: Double flare fittings can withstand very high pressures.
• Ease of installation: Flare fittings can be installed using simple hand tools.
• Reusable: Flare fittings can be disconnected and reconnected multiple times.
• Variety of materials: Available in different materials to suit specific applications.

Limitations of Flare Fittings

• Skill required: Flaring tubes requires specialized tools and skills to achieve a proper seal.
• Tube preparation: The tube must be properly prepared by cutting, deburring, and flaring to ensure a secure connection.
• Not suitable for thin-walled tubes: Thin-walled tubes may not be able to withstand the flaring process.

Installation of Flare Fittings

Installing flare fittings requires the following steps:

• Cut and deburr the tube: Use a tube cutter to cut the tube squarely and remove any burrs or sharp edges.
• Flare the tube: Use a flaring tool to create a cone-shaped lip on the end of the tube.
• Insert the tube into the fitting: Slide the flared tube into the mating fitting.
• Tighten the fitting: Use a wrench to tighten the fitting until it reaches the specified torque.

Maintenance of Flare Fittings

Flare fittings require minimal maintenance. However, it is important to inspect them regularly for any signs of wear or damage. If a leak occurs, the fitting should be replaced.

What You Need to Know

Q: What is the difference between a single and double flare fitting?
A: Single flare fittings have one cone-shaped lip, while double flare fittings have two. Double flare fittings provide a more secure seal and are recommended for higher pressure applications.

Q: What type of flare fitting is best for hydraulic systems?
A: Double flare fittings are commonly used in high-pressure hydraulic systems due to their ability to withstand extreme pressures.

Q: Can flare fittings be reused?
A: Yes, flare fittings can be disconnected and reused multiple times. However, it is important to inspect the flared lip for any damage before reusing it.