The specific principle of danfoss differential pressure switch

The valve body and the travel switch of the danfoss differential pressure switch are assembled on a bottom plate. The grease enters the right chamber of the differential pressure valve body piston from the main pipe B under the action of pressure, and the main pipe A is unloaded. Once the pressure difference between the two main pipes reaches the set value, the piston moves to the left against the spring force in the left cavity, and pushes the travel switch to close the contacts 1 and 2, sends a pulse signal to the system electric control box, and orders the reversing valve. In the reversing direction, the main pipe A is pressed, B is unloaded, the piston is centered under the action of the spring in the two end cavity, the travel switch contacts 1 and 2 are disconnected, and the contact bridge is in the neutral position. The system starts the second cycle. Once the pressure difference between the main pipes A and B reaches the set value, the piston moves to the right, the travel switch contacts 3 and 4 close, and the pulse signal again reverses the reversing valve in the system. Start the next cycle of work. The application of differential pressure switch in HVAC system is mainly controlled according to the resistance and flow curve of HVAC equipment. Water side heat exchangers in HVAC (casing type, shell tube type, tube sheet type and common plate heat exchanger) Water filters, valves, and pumps all have their performance curves for pressure drop and flow. As long as the measured differential pressure on both sides of the differential pressure switch is compared with a preset value, the flow can be accurately controlled.