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, simultaneously, eliminates the risk of leakage.
Bellows measuring systems are based on an adult manufacturing technology. The production of metal bellows, for instance 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 are softened through an annealing process in a furnace at more than 600 �C and then drawn into long, thin-walled and seamless tubes.
Constant elasticity
The tubes are corrugated by using forming tools at ruthless, and then 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 needed 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 procedure connection. Its other end is in touch with the transmission mechanism. This means that the instrument includes a fully seamless measuring system without the need for just about any rubber sealing materials and the chance of leakage is eliminated. Moneygrubbing makes pressure switches with metal bellows suitable for a wide range of applications. Process reliability is also guaranteed with liquid media.
Permanent accuracy
A metal bellows changes its length in line with the pressure. Whenever Warning defined switch point is reached, it triggers the switching function with 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 includes a high linearity. The switch differential, which 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 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 find a few of our standard designs. If you have any questions, your contact will gladly help you.

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