صمام الملف اللولبي ومبدأ عمله ووظيفته

Step-by-step direct-acting solenoid valves combine the principles of direct-acting and pilot-operated operation. When there is no pressure difference between the inlet and outlet, when energized, the electromagnetic force will directly lift the pilot valve and the main valve’s closing member, gradually opening the valve. And when the inlet and outlet reach the starting pressure difference, after energizing, the electromagnetic force will act on the pilot small valve firstly, causing the pressure of the lower chamber of the main valve to rise and the pressure of the upper chamber to fall, and using the pressure difference to push open the main valve. When the power is off, the pilot valve will use the spring force or medium pressure to push the closing member downward, to achieve valve closure. Step-by-step direct-acting solenoid valves are characterized by the fact that they can work properly even under zero differential pressure, vacuum or high pressure, but they require greater power and must be installed horizontally.