Flare fitting
Encyclopedia
Flare fittings are a type of compression fitting
used with metal tubing, usually soft steel and ductile (soft) copper, though other materials are also used. Tube flaring is considered to be a type of forging
operation, and is usually a cold working procedure. During assembly, a flare nut is used to secure the flared tubing's tapered end to the also tapered fitting, producing a pressure-resistant, leak-tight seal. Flared connections offer a high degree of long-term reliability and for this reason are often used in mission-critical and inaccessible locations.
The tool used to flare tubing consists of a die that grips the tube and a mandrel
that is forced into the end of the tube to form the flare by cold working. The most common flare fitting standards in use today are the 45-degree SAE style, and the 37-degree AN
style, also used with the JIC
system. The AN/JIC style generally has a higher pressure rating for a given size tubing. SAE and AN/JIC fittings are completely incompatible due to the different flare angle. Further, AN fittings (or those complying with subsequent standards) and JIC fittings are not interchangeable for design-controlled applications due to differing quality standards.
Compression fitting
Compression fittings are used in plumbing and electrical conduit systems to join two tubes or thin-walled pipes together. In instances where two pipes made of dissimilar materials are to be joined , the fittings will also be made of one or more compatible materials appropriate for the connection...
used with metal tubing, usually soft steel and ductile (soft) copper, though other materials are also used. Tube flaring is considered to be a type of forging
Forging
Forging is a manufacturing process involving the shaping of metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: '"cold," "warm," or "hot" forging. Forged parts can range in weight from less than a kilogram to 580 metric tons...
operation, and is usually a cold working procedure. During assembly, a flare nut is used to secure the flared tubing's tapered end to the also tapered fitting, producing a pressure-resistant, leak-tight seal. Flared connections offer a high degree of long-term reliability and for this reason are often used in mission-critical and inaccessible locations.
The tool used to flare tubing consists of a die that grips the tube and a mandrel
Mandrel
A mandrel is one of the following:* an object used to shape machined work.* a tool component that grips or clamps materials to be machined.* a tool component that can be used to grip other moving tool components.- Variants :...
that is forced into the end of the tube to form the flare by cold working. The most common flare fitting standards in use today are the 45-degree SAE style, and the 37-degree AN
AN thread
The AN thread is a particular type of fitting used to connect flexible hoses and rigid metal tubing that carry fluid. It is a US military-derived specification that dates back to World War II and stems from a joint standard agreed upon by the Army and Navy, hence AN.AN sizes range from -2 to -32...
style, also used with the JIC
JIC fitting
JIC fittings, defined by the SAE J514 and MIL-F-18866 standards, are a type of flare fitting machined with a 37-degree flare seating surface. JIC fittings are widely used in fuel delivery and fluid power applications, especially where extremely high pressure is involved. The SAE J514...
system. The AN/JIC style generally has a higher pressure rating for a given size tubing. SAE and AN/JIC fittings are completely incompatible due to the different flare angle. Further, AN fittings (or those complying with subsequent standards) and JIC fittings are not interchangeable for design-controlled applications due to differing quality standards.