water solenoid valve, steam solenoid valve, refrigeration solenoid valve, low temperature solenoid valve, gas solenoid valve, fire solenoid valve, ammonia solenoid valve, gas solenoid valve, liquid so Principle: When energized, the electromagnetic force opens the pilot hole, the pressure in the upper chamber drops rapidly, and a pressure difference between the lower part and the lower part is formed around the closing member. The fluid pressure pushes the closing member upward to move the valve to open; when the power is off, the spring force leads the pilot. The hole is closed, and the inlet pressure passes through the bypass hole. The rapid chamber forms a lower high and high pressure difference around the valve closing member, and the fluid pressure pushes the closing member downward to close the valve. Features: The upper limit of the fluid pressure range is high, can be installed arbitrarily (customized), but must meet the fluid pressure difference conditions. 2, the difference between the solenoid valve from the valve structure and material and the principle, divided into six sub-categories: direct-moving diaphragm structure, step-by-step direct diaphragm structure, pilot diaphragm structure, direct-acting piston structure, Step-by-step linear motion piston structure and pilot piston structure. 3. Solenoid valves are classified according to their functions: water solenoid valve, steam solenoid valve, refrigeration solenoid valve, low temperature solenoid valve, gas solenoid valve, fire solenoid valve, ammonia solenoid valve, gas solenoid valve, liquid solenoid valve, miniature solenoid valve, Pulse solenoid valve, hydraulic solenoid valve normally open solenoid valve, oil solenoid valve, DC solenoid valve, high pressure solenoid valve, explosion-proof solenoid valve, etc.