While copper and steel tubes are usually joined by soldering, brazing or welding, there are times when a mechanical joint may be required or preferred. One of the ways to connect tubes mechanically is flaring. Flaring is a process to form the end of a tube to make a liquid-tight or a gas-tight connection.
If the tube ends are subjected to stress and fatigue the Double-lap flaring will offer additional strength. The joint is designed so that the inside surface of the flare has a larger diameter so it does not interfere with flow characteristics of the system. Double-lap flaring usually is formed in the same shapes and meets the same specifications as the Single Flare.
If you flare the tubing properly with the proper tools and right technique you’ll get the leak-proof connection Firstly, you need to cut the tubing to the proper length using the appropriate tool. Second step is to slide the compression nut on the tubing. The last thing is to use a flaring tool kit to make a flaring itself.
The most common flare tube ends and corresponding flare fitting standards in use today are the 45-degree SAE style, and the 37-degree AN style, also used with the JIC system. For a given size, the AN/JIC style tubing generally has a higher pressure rating Due to the different flare angle SAE and AN/JIC connections are completely incompatible. The hydraulic hoses are usually 37-1/2° flare connections, and the refrigeration and air conditioning industry usually uses 45° flare connections. According to NFPA 54/ANSI. Z223.1 National Fuel Gas Code, copper tubes used for natural gas, Liquefied Petroleum, or propane may use flared brass fittings of single 45°-flare type Nevertheless, all National Model Codes permit the use of flare fitting joints, the one should be consulted by the authority having jurisdiction (AHJ) to determine acceptance for a specific application
Different sizes of tubes require specific sets of equipment, but most flaring kits are easy to find and relatively inexpensive. You need to use a proper cutting tool to cut a tube. A flaring tool kit usually consists of two main pieces – a reamer and a flare form. A flare form is some kind of a clamp which has a number of holes designed to work with tubing of various diameter. The tubing is firmly held by the flare form, allowing you to flare the pipe using minimum strength A reamer has a conical point, a screw, and holding arms and makes the actual flaring.