How to operate manually during the assembly process-PFA valve, medication valve, explosion-proof valve, comprehensive manufacturer

How to operate manually during the assembly process: In the state where the 2 (B) and 4 (A) ports of the valve are not connected and compressed air is continuously released into the atmosphere from the valve port, the internal pilot pressure used to switch the main valve will not increase to the necessary minimum pressure, which may result in the inability of the main valve to switch. Please manually operate the valve after piping the cylinder.