Tracing back to the development history of solenoid valves, so far, solenoid valves at home and abroad are divided into three categories in principle (ie: direct-acting, step-by-step direct-acting, pilot-operated), and in terms of valve disc structure and materials The differences and differences in principle are divided into six sub-categories (direct-acting diaphragm structure, step-by-step diaphragm structure, pilot-operated diaphragm structure, direct-acting piston structure, step-by-step piston structure, and pilot piston structure).
(1) Direct-acting solenoid valve
Principle: When energized, the electromagnetic coil generates electromagnetic force to lift the closing member from the valve seat, and the valve opens; when the power is turned off, the electromagnetic force disappears, and the spring force presses the closing member on the valve seat, and the valve closes.
Features: It can work normally in vacuum, negative pressure and zero pressure, but the general diameter does not exceed 25mm.
(two), step-by-step direct-acting solenoid valve
Principle: It is a combination of direct-acting and pilot-operated. When the pressure difference between the inlet and outlet is ≤0.05Mpa, when the power is turned on, the electromagnetic force directly lifts the pilot small valve and the main valve closing part upwards in sequence, and the valve opens. When the pressure difference between the inlet and the outlet is >0.05Mpa, when the power is turned on, the electromagnetic force first opens the small pilot valve, the pressure in the lower chamber of the main valve rises, and the pressure in the upper chamber drops, so that the main valve is pushed upward by the pressure difference; when the power is turned off, the pilot valve And the main valve uses the spring force or medium pressure to push the closing member, move down, and close the valve.
Features: It can also work reliably under zero pressure difference or vacuum or high pressure, but the power is relatively large, and vertical installation is required.
(three), pilot solenoid valve
Principle: When energized, the electromagnetic force opens the pilot hole, and the pressure in the upper chamber drops rapidly, forming a pressure difference around the closing member, which pushes the closing member to move upward, and the valve opens; when the power is turned off, the spring force closes the pilot hole , the inlet pressure quickly enters the upper chamber through the bypass hole and forms a pressure difference around the valve closing member, which pushes the closing member to move downward and closes the valve.
Features: The upper limit of the fluid pressure range is very high, but the fluid pressure difference condition must be met.
At present, the commonly used solenoid valves sold in China include more than a dozen varieties of DV (DVF), PGA, PEB (PESB), and BPE series, with diameters ranging from 3/4” to 3”, mainly used in agriculture, gardens, golf, and industrial dust prevention. and fountains. Commonly used solenoid valves are mostly diaphragm valves. Its working principle is: the valve body is divided into upper and lower chambers, with a diaphragm in the middle. Purpose. Solenoid valve open state - when the electric signal is given by the remote controller or the solenoid head is manually rotated, the drainage channel is opened, the water in the upper diaphragm chamber is discharged, the indoor pressure decreases, the pressure acting on the upper diaphragm becomes smaller, and the upstream pressure acts Push the diaphragm upward to open the pipeline channel. Solenoid valve closed state - manually close or disconnect the electric signal of the solenoid head, so that the drainage channel is closed, and the upper diaphragm chamber is slowly filled with water. Large, the diaphragm moves down, closing the tubing passage. The single solenoid has only one solenoid head. After the power is turned on, the solenoid valve changes direction. After the power is turned on, the solenoid valve changes direction. After the power is lost, the solenoid valve maintains its position. The solenoid valve on the other side must be powered on to return to its original position.
Tracing back to the development history of solenoid valves, so far, solenoid valves at home and abroad are divided into three categories in principle (ie: direct-acting, step-by-step direct-acting, pilot-operated), and in terms of valve disc structure and materials The differences and differences in principle are divided into six sub-categories (direct-acting diaphragm structure, step-by-step diaphragm structure, pilot-operated diaphragm structure, direct-acting piston structure, step-by-step piston structure, and pilot piston structure).
(1) Direct-acting solenoid valve
Principle: When energized, the electromagnetic coil generates electromagnetic force to lift the closing member from the valve seat, and the valve opens; when the power is turned off, the electromagnetic force disappears, and the spring force presses the closing member on the valve seat, and the valve closes.
Features: It can work normally in vacuum, negative pressure and zero pressure, but the general diameter does not exceed 25mm.
(two), step-by-step direct-acting solenoid valve
Principle: It is a combination of direct-acting and pilot-operated. When the pressure difference between the inlet and outlet is ≤0.05Mpa, when the power is turned on, the electromagnetic force directly lifts the pilot small valve and the main valve closing part upwards in sequence, and the valve opens. When the pressure difference between the inlet and the outlet is >0.05Mpa, when the power is turned on, the electromagnetic force first opens the small pilot valve, the pressure in the lower chamber of the main valve rises, and the pressure in the upper chamber drops, so that the main valve is pushed upward by the pressure difference; when the power is turned off, the pilot valve And the main valve uses the spring force or medium pressure to push the closing member, move down, and close the valve.
Features: It can also work reliably under zero pressure difference or vacuum or high pressure, but the power is relatively large, and vertical installation is required.
(three), pilot solenoid valve
Principle: When energized, the electromagnetic force opens the pilot hole, and the pressure in the upper chamber drops rapidly, forming a pressure difference around the closing member, which pushes the closing member to move upward, and the valve opens; when the power is turned off, the spring force closes the pilot hole , the inlet pressure quickly enters the upper chamber through the bypass hole and forms a pressure difference around the valve closing member, which pushes the closing member to move downward and closes the valve.
Features: The upper limit of the fluid pressure range is very high, but the fluid pressure difference condition must be met.
At present, the commonly used solenoid valves sold in China include more than a dozen varieties of DV (DVF), PGA, PEB (PESB), and BPE series, with diameters ranging from 3/4” to 3”, mainly used in agriculture, gardens, golf, and industrial dust prevention. and fountains. Commonly used solenoid valves are mostly diaphragm valves. Its working principle is: the valve body is divided into upper and lower chambers, with a diaphragm in the middle. Purpose. Solenoid valve open state - when the electric signal is given by the remote controller or the solenoid head is manually rotated, the drainage channel is opened, the water in the upper diaphragm chamber is discharged, the indoor pressure decreases, the pressure acting on the upper diaphragm becomes smaller, and the upstream pressure acts Push the diaphragm upward to open the pipeline channel. Solenoid valve closed state - manually close or disconnect the electric signal of the solenoid head, so that the drainage channel is closed, and the upper diaphragm chamber is slowly filled with water. Large, the diaphragm moves down, closing the tubing passage. The single solenoid has only one solenoid head. After the power is turned on, the solenoid valve changes direction. After the power is turned on, the solenoid valve changes direction. After the power is lost, the solenoid valve maintains its position. The solenoid valve on the other side must be powered on to return to its original position.