Understanding thread types is crucial for any project involving fluid transfer. One common type is the inverted flare thread, often found in automotive and refrigeration systems. But how do you identify it, and more importantly, what fitting mates correctly with an inverted flare? This blog post will delve into the specifics of inverted flare threads, explaining their unique characteristics and guiding you through the process of selecting the right mating component.
We’ll explore the dimensions, angles, and materials commonly associated with inverted flare fittings. By understanding these details, you can confidently choose the correct fitting, ensuring a leak-free and reliable connection. We’ll also offer tips on identifying potential compatibility issues and avoiding costly mistakes.
What Is An Inverted Flare Thread?
Inverted flare threads are a type of fitting commonly used in hydraulic systems, particularly in automotive applications like brake lines and fuel systems. They are designed to create a secure, leak-proof connection in high-pressure environments.
Unlike other types of flare fittings, the “inverted” aspect refers to the way the tubing is flared. Instead of flaring outward, the end of the tubing is flared inward, creating a cone shape that fits into a corresponding concave seat within the fitting.
This design offers several advantages. The inward flare provides a larger sealing surface compared to traditional outward flares, enhancing the connection’s strength and resistance to leaks. Additionally, the internal positioning of the flare protects it from damage and contamination, contributing to the fitting’s durability and longevity. Inverted flare threads are known for their ability to withstand high pressures and vibrations, making them a reliable choice for critical applications where leaks are unacceptable.
What Fitting Mates With an Inverted Flare Thread?
Inverted flare fittings are a type of tube fitting commonly used in high-pressure applications like brake lines, fuel lines, and hydraulic systems. They are designed to create a reliable, leak-free seal by using a 45-degree flare on the male fitting that seats against a matching 45-degree flare in the female fitting.
Here are the key components of inverted flare fittings and how they work:
- Male inverted flare fitting: This fitting has a 45-degree flare on the end of the tube. This flare is carefully formed using a flaring tool.
- Female inverted flare fitting: This fitting has a matching 45-degree flare inside the fitting body.
- Nut: The nut slides over the tube and threads onto the male fitting. As the nut is tightened, it compresses the flare between the male and female fittings, creating a tight seal.
Advantages of inverted flare fittings:
- Reliable seal: The 45-degree flare provides a large surface area for contact, ensuring a strong and leak-free connection.
- High-pressure resistance: Inverted flare fittings are designed to withstand high pressures, making them suitable for demanding applications.
- Easy to assemble: While flaring the tube requires some skill, the overall assembly process is relatively straightforward.
- Reusable: Inverted flare fittings can be disassembled and reassembled multiple times without compromising the seal.
Important considerations:
- Proper flaring: It’s crucial to flare the tube correctly to ensure a proper seal. Using the right flaring tool and following the instructions carefully is essential.
- Thread compatibility: Make sure the threads on the male and female fittings are compatible.
- Torque: Overtightening the nut can damage the fitting or split the tubing. It’s important to tighten the nut to the recommended torque specification.
What Are Inverted Flare Fittings Used For?
Inverted flare fittings are used in a variety of applications where a reliable, leak-free seal is required in high-pressure systems. Here are some of the most common uses:
- Automotive: Inverted flare fittings are commonly used in brake lines, fuel lines, and power steering lines. They are also found in transmission cooler lines and other hydraulic systems.
- Hydraulic systems: Inverted flare fittings are used in a wide range of hydraulic applications, including industrial machinery, construction equipment, and agricultural equipment.
- Refrigeration and HVAC: Inverted flare fittings are used in refrigeration and HVAC systems to connect refrigerant lines.
- Fuel and gas delivery systems: Inverted flare fittings are used in fuel and gas delivery systems to connect fuel lines and gas lines.
- Marine applications: Inverted flare fittings are used in marine applications to connect hydraulic lines and fuel lines.
- Heavy machinery and equipment: Inverted flare fittings are used in heavy machinery and equipment to connect hydraulic lines and fuel lines.
- Home plumbing and gas systems: Inverted flare fittings are used in home plumbing and gas systems to connect gas lines and water lines.
- Instrumentation and laboratory equipment: Inverted flare fittings are used in instrumentation and laboratory equipment to connect fluid and gas lines.
In general, inverted flare fittings are used in any application where a reliable, leak-free seal is required in a high-pressure system. They are particularly well-suited for applications where vibration is a concern, such as in automotive and hydraulic systems.
What Connects to a Flare Fitting?
A flare fitting connects to a tube or pipe that has been flared using a flaring tool. The flared end of the tube fits into the flare fitting, and a nut is tightened to secure the connection. This creates a leak-tight seal that is resistant to high pressure and vibration.
Flare fittings are commonly used in a variety of applications, including:
- Automotive: Brake lines, fuel lines, power steering lines
- Hydraulic systems: Industrial machinery, construction equipment
- Refrigeration and HVAC: Refrigerant lines
- Plumbing: Gas lines, water lines
Flare fittings are a reliable and versatile way to connect tubes and pipes in a variety of applications. They are easy to install and can be used with a variety of materials, including copper, steel, and aluminum.
How Do You Join a Flare Fitting?
Joining a flare fitting involves a few key steps to ensure a proper, leak-free connection:
1. Prepare the tubing:
- Cut the tubing: Use a tube cutter to make a clean, straight cut on the end of the tubing.
- Deburr the cut: Remove any burrs or sharp edges from the cut end of the tubing using a deburring tool or file. This will help prevent damage to the fitting and ensure a smooth flare.
- Clean the tubing: Clean the end of the tubing to remove any dirt, debris, or oil.
2. Flare the tubing:
- Slide the flare nut: Slide the flare nut onto the tubing with the threads facing away from the end to be flared.
- Insert the tubing: Insert the tubing into the flaring tool, ensuring it is properly positioned and secured.
- Flare the tubing: Use the flaring tool to create a 45-degree flare on the end of the tubing. Follow the instructions provided with your flaring tool.
- Inspect the flare: Check the flare to ensure it is smooth, even, and free of cracks or imperfections.
3. Connect the fitting:
- Apply lubricant: Apply a small amount of lubricant to the flare fitting and the flared end of the tubing. This will help prevent seizing and ensure a smooth connection.
- Align the fitting: Align the flared end of the tubing with the flare fitting.
- Tighten the nut: Tighten the flare nut onto the fitting by hand until it is snug.
- Use wrenches: Use two wrenches to tighten the connection further. One wrench should be used to hold the fitting steady, while the other is used to tighten the nut.
- Tighten to specification: Tighten the nut to the torque specification recommended by the manufacturer. Overtightening can damage the fitting or tubing.
4. Check for leaks:
- Test the connection: After the connection is made, test it for leaks using a soapy water solution or a leak detector.
- Tighten if necessary: If a leak is detected, tighten the nut slightly more.
Tips for joining flare fittings:
- Use the correct tools: Use a high-quality tube cutter, flaring tool, and wrenches.
- Follow instructions: Carefully follow the instructions provided with your flaring tool and fittings.
- Practice: If you are new to flaring fittings, practice on some scrap tubing first.
- Inspect carefully: Inspect the flare and the connection carefully to ensure they are properly made.
- Don’t overtighten: Overtightening can damage the fitting or tubing.
By following these steps, you can create a reliable, leak-free connection using flare fittings.
What Are the Two Standards for Flare Fittings?
There are two main standards for flare fittings:
- SAE 45-degree flare fittings: These fittings have a 45-degree flare angle and are commonly used in automotive, refrigeration, and plumbing applications. They are suitable for low to medium pressure systems.
- JIC 37-degree flare fittings: These fittings have a 37-degree flare angle and are commonly used in hydraulic systems. They are suitable for high pressure systems.
Here are the key differences between the two standards inverted flare fittings in the following:
| Feature | SAE 45-degree flare fittings | JIC 37-degree flare fittings |
|---|---|---|
| Flare angle | 45 degrees | 37 degrees |
| Common applications | Automotive, refrigeration, plumbing | Hydraulic systems |
| Pressure rating | Low to medium | High |
| Interchangeability | Not interchangeable with JIC fittings | Not interchangeable with SAE fittings |
It is important to note that these are just the two main standards for flare fittings. There are other standards as well, such as AN flare fittings, which are also 37-degree flare fittings but are made to stricter military specifications.
When choosing flare fittings, it is important to consider the specific application and the pressure requirements of the system. Using the wrong type of flare fitting can lead to leaks and even catastrophic failure.
What is the Angle of an Inverted Flare?
An inverted flare fitting uses a 45-degree flare angle. This is a critical part of its design, as it must match the 45-degree flare on the male fitting it connects to.
Are Jic and an Fitting Compatible?
JIC (Joint Industry Council) and AN (Army-Navy) fittings, while both utilizing a 37-degree flare angle, are not ideally interchangeable due to differences in thread tolerances and manufacturing standards.
While they can physically connect, AN fittings are manufactured to more stringent military specifications with tighter tolerances, making them suitable for high-pressure and high-vibration environments like aerospace applications. JIC fittings, designed for general industrial use, have looser tolerances and are more cost-effective.
Interchanging them in non-critical applications might be possible, but using JIC fittings in place of AN fittings in demanding situations could lead to leaks and equipment failure.
Therefore, it’s crucial to select the appropriate fitting based on the specific application requirements to ensure optimal performance and safety.
When to Use a Flare Fitting?
Flare fittings are ideal for creating reliable, leak-free connections in high-pressure applications where frequent assembly and disassembly might be necessary.
They are particularly well-suited for situations involving vibration, like automotive brake lines or hydraulic systems, as the flared connection provides a robust seal. Use flare fittings when you need a dependable connection that can withstand pressure fluctuations and movement, and where ease of maintenance or component replacement is a consideration.
Conclusion
In conclusion, understanding which fittings mate with inverted flare threads is crucial for ensuring leak-free and reliable hydraulic systems. Inverted flare fittings, characterized by their unique outward-angled flare, require a mating fitting with a corresponding inward-angled flare. This ensures a secure and leak-proof connection. By selecting the correct fittings, you can prevent costly leaks, downtime, and potential safety hazards.
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Contact us today to learn more about our1 wholesale program and how we can help you find the perfect inverted flare fittings for your applications. Don’t hesitate to reach out – we’re here to assist you!
