What advantages do pressure switches with metal bellows offer and what’s 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 risk 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, occurs in a number of steps. Corrupting are first cut from a flat piece of metal, and they are then shaped into cup-shaped objects. They’re softened via an annealing process in a furnace at more than 600 �C and drawn into long, thin-walled and seamless tubes.
Constant elasticity
The tubes are corrugated by using forming tools at ruthless, and are trimmed to the designed size. Within 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 ultimate 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. Ignite is in contact with the transmission mechanism. Therefore the instrument includes 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 suitable for an array of applications. Process reliability can be guaranteed with liquid media.
Permanent accuracy
A metal bellows changes its length good 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, which is precisely adjusted with a specific calibrated spring system, remains correspondingly constant. This ensures the accuracy of pressure control and switching, even over an extended 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 some of our standard designs. When you have any questions, your contact will gladly help you.