Main Classification Of Solenoid Valves

1. Solenoid valves are divided into three categories in principle:
Direct-acting solenoid valve
Principle: When powered on, the electromagnetic coil generates electromagnetic force to lift the closing part from the valve seat, and the valve opens; when powered off, the electromagnetic force disappears, the spring presses the closing part on the valve seat, and the valve closes.
Features: It can work normally under vacuum, negative pressure, and zero pressure, but the diameter generally does not exceed 25mm.
Step-by-step direct-acting solenoid valve
Principle: It is a principle that combines direct-acting and pilot-operated. When there is no pressure difference between the inlet and outlet, after power is turned on, the electromagnetic force directly lifts the pilot small valve and the main valve closing part upward in turn, and the valve opens. When the inlet and outlet reach the starting pressure difference, after power is turned on, the electromagnetic force pilots the small valve, the pressure in the lower chamber of the main valve rises, and the pressure in the upper chamber drops, thereby using the pressure difference to push the main valve upward; when power is off, the pilot valve uses the spring force or medium pressure to push the closing part downward to close the valve.
Features: It can also work at zero pressure difference or vacuum or high pressure, but the power is large and it must be installed horizontally.
Pilot solenoid valve
Principle: When the power is on, the electromagnetic force opens the pilot hole, the pressure in the upper chamber drops rapidly, and a pressure difference with a low top and a high bottom is formed around the closing part. The fluid pressure pushes the closing part upward and the valve opens; when the power is off, the spring force closes the pilot hole, and the inlet pressure quickly passes through the bypass hole to form a pressure difference with a low bottom and a high top around the closing valve part. The fluid pressure pushes the closing part downward and closes the valve.
Features: The upper limit of the fluid pressure range is relatively high, and it can be installed arbitrarily (customization is required), but the fluid pressure difference conditions must be met.
2. Solenoid valves are divided into six subcategories based on the differences in valve structure and materials and principles: direct-acting diaphragm structure, step-by-step direct-acting diaphragm structure, pilot diaphragm structure, direct-acting piston structure, step-by-step direct-acting piston structure, and pilot piston structure.
3. Solenoid valves are classified according to their functions: water solenoid valves, steam solenoid valves, refrigeration solenoid valves, low-temperature solenoid valves, gas solenoid valves, fire solenoid valves, ammonia solenoid valves, gas solenoid valves, liquid solenoid valves, miniature solenoid valves, pulse solenoid valves, hydraulic solenoid valves, normally open solenoid valves, oil solenoid valves, DC solenoid valves, high-pressure solenoid valves, explosion-proof solenoid valves, etc.