Simply stated, edge welded bellows are manufactured by welding stamped, metal diaphragms into a long, flexible assembly. Strips of metal in sheet form are hydraulically stamped into the shape of the diaphragm. The pressure, stroke length, spring rate and temperature help to determine the thickness and material required to meet the applications' demands.The shape of the ripples and inside and outside edges of the diaphragm are crucial to the performance of the bellows assembly. The ripples need consistency between diaphragms to survive high cycles and create accurate spring rates. The inside and outside diameters will be welded later in the process; with properly stamped edges, butt welding machine factory are leak-tight.Once stamped, diaphragms are inspected for quality and cleaned. The cleaning preparation varies between manufacturers, but the main focus is to ensure that the material is free of any grease or dirt to ensure the welds are strong and leak-tight. The diaphragms need special handling after the process as well to ensure that the natural oils of skin do not come into contact with the diaphragms.The diaphragms are positioned back-to-back (male to female) to pair the inside diameter holes. Once the inside diameters come into contact with each other, they are welded together. Depending on the manufacturer and material, welding can be accomplished through plasma, laser, arc, or electron beam welding equipment. Vision systems can aid the accuracy and consistency of welds. This process is continued in order to make the proper number of convolutions. The convolutions give the bellows assembly the flexibility and performance characteristics.Once the inside diameter welds are completed, the convolutions can be prepared for outside diameter welding. Depending on the welding equipment, copper rings can be inserted between the convolutions in order to ensure that the heat from the welds does not distort or change material properties in the adjacent material.
