Flared connections offer a high degree of long-term reliability and for this reason are often used in mission-critical and inaccessible locations.
For high pressure, flare joints are made by doubling the tube wall material over itself before the bell end is formed.
Flared fittings are an alternative to solder-type joints that are mechanically separable and doesn’t require an open flame.
Many plumbing codes, towns, and water companies require copper tube used for water service to be type-L or type-K. All National Model Codes permit the use of flare fitting joints, however, the authority having jurisdiction (AHJ) should be consulted to determine acceptance for a specific application.
[5] The reaming tool deforms only the end of the pipe in a plastic way, thus increasing its inner and outer diameters to the required parameters.
The main disadvantages of using such a tool are the inability to control the accuracy of the fit and the high probability of deformation of the walls where they should remain straight.
The most common is a tool design with a die and a cone, which is screwed through the handle until the edges are separated at the required angle.