Pressure switches with metal bellows: Stable repeatability, no risk of leakage

What advantages do pressure switches with metal bellows offer and what’s the basis for these? The advantages are based on the seamless design of these measuring system. This solution enables permanently stable repeatability and, at the same time, eliminates the risk of leakage.
Bellows measuring systems derive from a mature manufacturing technology. The production of metal bellows, for example from stainless steel or perhaps a copper alloy, takes place in a number of steps. Circular discs are first cut from a flat piece of metal, and these 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 then drawn into long, thin-walled and seamless tubes.
Constant elasticity
The tubes are corrugated through the use of forming tools at high pressure, and are trimmed to the designed size. In the next stage, the spring-like metal cylinders are pressed together in accordance with 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 for pressure switches
Seal-free functionality
In a pressure switch, the metal bellows is brazed or welded to the process connection. Its other end is in contact with the transmission mechanism. This means that the instrument has a fully seamless measuring system with no need for any rubber sealing materials and the chance of leakage is eliminated. This feature makes pressure switches with metal bellows ideal for a variety of applications. Process reliability can be guaranteed with liquid media.
Permanent accuracy
A metal bellows changes its length based on the pressure. When a defined switch point is reached, it triggers the switching function via a transmission mechanism. If Quality 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, which is precisely adjusted via 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 home elevators pressure switches with metal bellows, e.g. models PSM-520, PSM-550 and PSM-700, are available on the WIKA website. You would like to buy pressure switches with metal bellows? Inside our WIKA online-shop you will discover a few of our standard designs. Should Murder have any questions, your contact will gladly help you.

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