Tube and Duct Forming
The applications of metal tubes and ducts in an aircraft are signicant and many are associated with the manufacture and installation of the environmental control systems in the aircraft, including heating, ventilation, air conditioning, oxygen, and pressurization and depressurization systems. In addition to the environmental control system, there are applications in the auxiliary power unit, air handling unit ducts, and wire management conduits, as well as uid containment tanks. The applications of hydraulic tubing in the aircraft are mainly in the landing gear operating system, the wing trailing edge ap, and the leading edge slat actuation systems, as well as engine operating systems. There are also applications of metal tubes as control rods, struts, actuation and push rods, links, and more. The metal tubes for aerospace applications are mainly seamless hollow products made with various metal-forming technologies discussed in Sections 4.6 through 4.8. The ducts are generally fabricated using sheet metal forming and welding technologies. This chapter introduces an overview of major tube-and duct-forming processes as illustrated in Figure 13.1.