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Principle and Function of Differential Pressure Switch

Principle of differential pressure switch:

The differential pressure switch is a kind of mechanical switch. There is a diaphragm or bellows in a pressure chamber to divide the pressure chamber into two chambers for low port and high port. The two chambers have high and low pressure end interfaces respectively. The high-pressure port is connected with the high-pressure pipe, and the low-pressure port is connected with the low-pressure pipe (it can't be connected reversely, otherwise the diaphragm or bellows will be broken) to transmit pressure at the same time. At this time, the high and low pressure offset each other to form a pressure difference value, It changes elastically through the mechanical pressure sensing element and gives the on or off signal by setting to a certain extent. It is just a signal generator. When the normally open and normally closed contacts of the differential pressure switch are connected to the relay or PLC, they can enter the control system.

Differential Pressure Switches detecting the water flow of pump
Made by A.YITE TECH, GE-511 series, adjustable differential pressure switch

At the same time, the dead-band of the differential pressure switch is very important. The dead time is the return difference. The dead-band cannot be too large.

Function of differential pressure switch:

1. As a monitoring instrument for water flow control and water pump and water filter status, it is widely used in large, medium and small air-cooled or water-cooled chillers using plate heat exchanger, sleeve heat exchanger and shell and tube heat exchanger.

2. It is used in gas detection, widely used in air conditioning and clean room, fan and filter blowing control

3. The differential pressure switch can also be used on the differential pressure filter and dust remover of the water treatment system