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The Role of Pressure Switch and Precautions for Use

Pressure switch, a switch element widely used in the fields of Heating Ventilation Air Conditioning (HVAC), water treatment, water system control, air compressor control, etc., for measuring gas, liquid pressure and other automation systems. Let's get to know the pressure switch.


The pressure switch is mainly used to detect the pressure of the relevant detected parts. Its working principle is to sense the pressure of the external environment through an external diaphragm. When the external pressure exceeds or falls below the safety-critical point, the diaphragm will guide the pressure to the transmission rod and the rare metal contact to control the opening or closing of the bridge, and the signal will guide the switch to change, so when the pressure of the environment recovers to the normal limit, the internal diaphragm of the sensor will move to the original position, so that the switch will reset actively to avoid unnecessary safety hazards.


1. What is the function of the pressure switch?


The pressure switch is a high-precision device that mechanically detects pressure and liquid level signals, and realizes the monitoring and control of pressure and liquid level. Because the adjustment is convenient and flexible, the installation is simple, and the cost is low, it can replace liquid level switches on most occasions.


The operation of pressure switch: When the pressure in the system is higher or lower than the rated safety pressure, the disc in the sensor moves instantaneously, and the switch connector is turned on or off through the connecting guide rod. When the pressure drops or rises to the rated recovery value, the disc is reset instantly, the pressure switch automatically resets. Or simply put, when the measured pressure exceeds the rated value, the free end of the elastic element is displaced, and the switch element is pushed directly or after comparison to change the on-off state of the switch element, so as to achieve the purpose of controlling the measured pressure. The elastic components used in the pressure switch include single-turn springs, diaphragms, transmission rods, rare metal contacts and electric bridges.


2. The use of the pressure switch and precautions


In the selection of pressure switches, we should pay attention to these points: the necessity of explosion-proof; whether it is necessary to have instructions: conform to customer needs; number of contacts: one contact (one output) or two contacts (two outputs); confirmation of set value and pressure scale: It is recommended to set the scale between 30% and 65% of the pressure scale, and the settable scale is between 15% and 90% of the pressure scale; the way of disconnection: adjustable or fixed type.