A bellows is a device for delivering pressurized air in a controlled quantity to a controlled location. Basically, a bellows is a deformable container which has an outlet nozzle. When the volume of the bellows is decreased, the air escapes through the outlet. A bellows typically also has a separate inlet and valves or flaps for ensuring that air enters only through the inlet and exits only through the outlet. Metallurgy Several processes, such as metallurgical iron smelting and welding, requi… (More on Bellows)