What advantages do pressure switches with metal bellows offer and what is the foundation for these? Advantages derive from the seamless design of their measuring system. This solution enables permanently stable repeatability and, at the same time, eliminates the chance of leakage.
Bellows measuring systems are based on a mature manufacturing technology. The production of metal bellows, for example from stainless steel or a copper alloy, takes place in several steps. Circular discs are first cut from the flat piece of metal, and they are then shaped into cup-shaped objects. They’re softened via an annealing process in a furnace at a lot more than 600 �C and drawn into long, thin-walled and seamless tubes.
Constant elasticity
The tubes are corrugated through the use of forming tools at ruthless, and then are trimmed to the designed size. Within the next stage, the spring-like metal cylinders are pressed together relative to the specified dimensions (length, outer and inner diameter). This creates the constant elasticity necessary for the stable repeatability of the movement. In the final step, the bellows are degreased and passivated, i.e. given a protective coating against corrosion.
Bellows manufactured from stainless steel for pressure switches
Seal-free functionality
In a pressure switch, the metal bellows is brazed or welded to the procedure connection. Its other end is in touch with the transmission mechanism. Therefore the instrument has a fully seamless measuring system without the need for any rubber sealing materials and the risk of leakage is eliminated. This feature makes pressure switches with metal bellows ideal for a variety of applications. Risky is also guaranteed with liquid media.
Danger bellows changes its length in line with the pressure. Whenever a defined switch point is reached, it triggers the switching function via a transmission mechanism. If the pressure drops or rises again, the bellows returns to its original shape and the switch contact returns to its original position.
The expansion movement of a metal bellows has a high linearity. The switch differential, that is precisely adjusted with a specific calibrated spring system, remains correspondingly constant. This ensures the accuracy of pressure control and switching, even over a long period of time.
Note
Detailed info on pressure switches with metal bellows, e.g. models PSM-520, PSM-550 and PSM-700, can be found on the WIKA website. You would like to buy pressure switches with metal bellows? In our WIKA online-shop you will discover a few of our standard designs. Should you have any questions, your contact will gladly assist you to.