Even though copper and steel tubes are usually joined by soldering, brazing or welding, there are times when a mechanical joint may be required or preferred. If you join tubes with a mechanical connection you need flaring. Flaring is used to do gas-tight or liquid-tight connection, and this process means forming the end of a tube.
The simplest and the most used technique of flaring is called a single 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.
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 flaring tool kit usually consists of two main pieces – a reamer and a flare form. A flare form is like a clamp with a number of holes used for various tube diameters. It holds the pipe firmly so you can flare the pipe with minimum efforts A reamer has a conical point, a screw, and holding arms and makes the actual flaring.
To make sure that the jointof tubes using fitting will be leak-tight, you have to flare tubing properly using the proper tools and techniques. Firstly, you need to cut the tubing to the proper length using the appropriate tool. Secondly, don’t forget to slide the compression nut on a tubing The last step is to use a flaring tool kit to make a flaring itself.
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. The AN/JIC style generally has a higher pressure rating for a given size tubing. SAE and AN/JIC connections are completely incompatible due to the different flare angle. The refrigeration and air conditioning industry usually uses 45° flare connections while hydraulic hoses are usually 37-1/2° 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
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.