JIC Fittings (Joint Industry Council Fittings)
Introduction
JIC fittings stand for Joint Industry Council Fittings are one of the most commonly used compression or hydraulic fittings used in fuel delivery systems. They are also called 37 degrees JIC fitting or flare fitting. They are described by SAE J514 standard as a type of flare fitting that has a 37° JIC adapter fitting having a 37° cone seat on the female adapter and a 37° flare seating surface on the male adapter. This cone seat and flare allow for a complete mechanical seal between the male and female fitting. It is a mechanical connection that is made between the female cone seat and a male flare. Teflon tape or pipe thread sealant is not required.
The flare design is useful because it makes recurring or frequent tubing assembly and disassembly easier without the need of replacing the components or parts thereof. There are a variety of configurations available in the market, for instance, elbows, tees, cross and straight connectors, etc.
Flared tube fittings have significant performance characteristics that make it suitable to be used with thin to medium walled tubes. As the flared fittings provide secure and reliable seal, several high-pressure hydraulic systems applications have started using them as a replacement for pipe fittings. The SAE 37 degree is the standard fitting that is most commonly used in hydraulic systems. The SAE standard fittings are used with tubes having thick walls.
JIC fittings are almost similar to AN (Army-Navy) fitting but they cost less and have lower tolerance as compared to the AN (Army-Navy) fittings. It is often confused for AN (Army-Navy) fittings It is available in different materials including stainless steel, carbon steel, brass, and copper. JIC fitting and AN (Army-Navy) fitting is dimensionally the same, however, they are not interchangeable due to their different functionalities. JIC fittings are also confused with SAE 45 degree flared fitting because few sizes have identical threads. Therefore, it is always necessary to take extra care in order to make sure that they provide a secure and reliable seal that is leak proof.
How JIC Fittings Are Used?
The JIC fitting consists of mainly three pieces: the body, flare nut, and sleeve.
JIC fittings depend on the metal-to-metal connection between the fitting and the inner diameter of the flared tube in order to form a seal. When the fitting and the flared tubing are connected, they are backed by sleeve-fitting that spreads the compressed load of the nut during assembly. It is easy to identify an SAE tubing system because the sleeve bulges out from the back of the nut. It extends the tube while providing added support and decreasing the load on the fitting.
Applications
JIC fittings are considered an excellent choice for preventing leaks and can be used for higher pressure applications. JIC fittings are usually used for fuel or fluid supply applications. They are used for high-pressure applications up to 10,000 psi. Previously, JIC fittings used to correspond to the military specification which was superseded later by SAE. However, there are several system designs as well as designers that prefer the JIC fittings conventionally.
JIC fittings are used in several commercial and industrial applications such as aerospace industry, and fluid power industries, etc. In the aerospace industry, they are used in the manufacture of different types of aerospace and space exploration equipment. In a fluid power system, it is used to provide a port inline circuit. This circuit helps in providing the measurements and pressure readings when connected to the diagnostic device.
Merits of Using JIC Fittings:
- They are easily and quickly available.
- They are available in several different styles, shapes, sizes, materials, and configurations.
- The sizes are in accordance with the SAE fittings which make them easy to identify and replace or interchange.
- They are considered suitable for use in high-temperature applications because of the absence of O ring. If they are made of stainless they can tolerate the temperature ranging from -425 to 1200°F, in case of brass they can tolerate temperature ranging from -40 to 400°F.
- They can be easily assembled and disassembled without any deformation. It is considered suitable for applications that require frequent changes or replacements.
- They are easy to install and require minimum maintenance.
- The combination of male flared fitting and female cone seat makes the orientation process easier.
Demerits of Using JIC Fittings
- They are not considered suitable for applications that have a high vibration.
- The metal-to-metal seal design makes it suitable only for limited applications such as hydraulic, liquid, fluid, or similar non-critical applications.
- The flare fittings can get damaged and cracked if they are over-tightened.