If you need to join steel or copper tubes together, you can do it by soldering, welding or brazing, and sometimes it’s preferred or even required to do it mechanically. If you connect tubes with a mechanical connection you need flaring. The process called flaring is a tube’s end forming, used for creating a gas- or liquid-tight connection.
The 45-degree SAE style, and the 37-degree AN style, also used with the JIC system are the common standards for flare tube ends and flare fitting in use today. 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
Most of flaring kits are relatively inexpensive and easy to find, despite the fact that different sizes of tubes require specific sets of equipment. You need to use a proper cutting tool to cut a tube. A common flaring tool kit has two main parts – a flare form and a reamer. A flare form is some kind of a clamp which has a number of holes designed to work with tubing of various diameter. It holds the pipe firmly so you can flare the pipe with minimum efforts The thing that makes the actual flaring is reamer, which has holding arms, a screw, and a conical point.
If the tube ends are subjected to stress and fatigue the Double-lap flaring will offer additional strength. The inside surface of the flare is designed with a larger diameter, that does not interfere with system’s flow characteristics. Double-lap flaring usually is formed in the same shapes and meets the same specifications as the Single Flare.
Single flaring is the most common and the simplest process of flaring Both 37 and 45-degree single flares options are available. Rotary or spinning the flared end, and a ram forming are two available ways to accomplish single flared tube end.