It clamps or loosens the hose by electromagnetic force to realize the function of passing or disconnecting. The hose material is usually silicone rubber hose. The electromagnetic pinch valve completely isolates the contact between the valve and the liquid, because only the pipeline transports the liquid, and the valve core does not contact with the liquid. The spool of ordinary solenoid valve is in contact with liquid. Therefore, it is not only used in medical devices, waste gas detection and water quality analysis devices, but also used in analytical equipment in many fields such as bioengineering and life sciences. That is, it is mainly used for: 1, chemical corrosive liquid (related to chemistry, the spool of ordinary solenoid valve will corrode when it contacts liquid); 2. A highly clean sterile liquid (such as medical liquid) is needed. In the instruments for measuring liquid or gas, including blood, physiological saline or clinical medical liquid, high-purity liquid can be successfully separated and separated under aseptic condition. The spool of ordinary solenoid valve contacts with liquid, which will cause pollution)