What are Metal Bellows?
Metal bellows are metallic vessels which are elastic in nature which gets compressed when pressure is applied to its sides whereas they extend under vacuum. This elastic nature of the bellows is due to its design where convolutions or also know as piles are made by deforming /compressing a metallic tube and using water under high pressures going up to 250 . This process is called hydroforming with multi-stage plastic deformation process. When the pressure or the vacuum is released, they return back to their original shape. But, care should be taken where the material or that bellow is not stressed past its yield strength. These metal bellows are used in piping systems where the temperature goes from high to very high units while in working conditions. It is the flexible element of the expansion joint. In piping systems, it is used to absorb the thermal growth of the pipe.
Manufacturing Process of Metal Bellows
The manufacturing process of the metal bellow starts with the designing process itself. First, a metallic tube is designed and then made/manufactured by shearing a sheet of metal and then rolling it into the desired sizes. Then, the desired life cycle of the bellow to be made with the expansion joint is first identified. This lets the designer determine the bellow thickness as he understands the working conditions, the pressure under which the expansion joint and thus ultimately the metal bellow will be working. After these calculations, the number of piles to be used is then determined. It is upto the engineer of the joint that the number of piles will be set for each bellow. The hydroforming process is implemented and the bellow is thus taken out. After this, longitudinal cuts are made on the piece and the neck is thus cut to the desired size or shape. Many manufacturing industries produce metal bellows as they are required in loads of situations where expansion joints are used.
How Pliant Bellows manufacture Metal Bellows?
There are many metal bellows manufacturers out there but Pliant Bellows manufacture strong and sturdy metal bellows to be used directly on expansion joints as per the order and the desired requirement. Expansion joint engineers face this usual problem of how to design it properly so that it is thick enough to withstand the pressure and thin enough to be flexible. Also, determining the alloy or the metal to be used is a hard job. We at Pliant are well experienced in these matters and of design equations based upon this empirical understanding. We comply with all the design rules laid out by the EJMA (Expansion Joint Manufacturing Association). The bellows we manufacture are led through operating and test conditions of varying pressures and temperatures. We take care they are corrosion resistant and have sufficient squirm stability. Hydroformed bellows are our speciality at Pliant.