Electric pressure bypass valve to control the role: 

 This system is suitable for central air conditioning, chilled water / hot water system pressure bypass control purposes. 
 Pressure bypass the main function is to maintain the chilled water / hot water system in the case of the lower end of the load, ensure the normal operation of the chillers / heat exchangers and other equipment. 

 How it works: 
 Differential pressure controller DPC-1 by testing for / backwater charge of the pressure difference, compared with the set value by controlling the opening degree of the electric two-way valve, water supply and return water to achieve bypass in order to maintain the required the pressure difference. 
 Pressure difference increases, the red contacts and yellow contacts connected to the pressure to reduce red contacts with blue contacts connected the red contacts can stay in the middle, there is no electrical connection with the other contact.