Jinzihao introduction of the working principle of the solenoid valve
(1), direct actuated solenoid valve
Principle: when electricity is electrified, the electromagnetic force of the electromagnetic coil is brought up from the seat and the valve is opened; when the power is broken, the electromagnetic force is disappearing and the spring force is pressed on the seat of the valve and the valve is closed.
Features: it works normally in vacuum, negative pressure and zero pressure, but the general diameter is no more than 25mm.
(two), stepwise direct actuated solenoid valve
Principle: it is a combination of direct and pilot, when the pressure difference between the entrance and exit is less than 0.05Mpa, when the electric power is connected, the electromagnetic force directly brings the pilot valve and the main valve close up, and the valve opens. When the inlet and outlet pressure difference is >0.05Mpa, the electromagnetic force opens the pilot valve first, the main valve lower chamber pressure rises, the upper chamber pressure drops, and the main valve is pushed open up by pressure difference; when the power is broken, the pilot valve and the main valve use spring force or medium pressure to push the closure, move down, and turn the valve down.
Features: it can work reliably at zero pressure difference or vacuum and high pressure, but the power is large, and it requires vertical installation.
(three), pilot solenoid valve
Principle: when electrifying, the electromagnetic force opens the pilot hole, the pressure of the upper chamber drops rapidly, forms a low high pressure difference around the closed part, drives the closing part to move upwards, and opens the valve; when the power is broken, the spring force closes the pilot hole and the entrance pressure quickly enters the upper chamber through the bypass hole to form lower lower around the valve parts. The high pressure difference pushes the shut-off parts to move downwards and close the valve.
Characteristics: the upper limit of fluid pressure range is very high, but the pressure difference condition of fluid must be satisfied.
Currently in the domestic sales of common electromagnetic valves DV (DVF), PGA, PEB (PESB), BPE series of more than a dozen varieties, the caliber from 3/4 "to 3", mainly used in agriculture, garden, golf, industrial dust and fountain and other fields. Commonly used solenoid valve diaphragm valve, its working principle is: the valve body is divided into two rooms, the middle for the diaphragm, under the same water pressure conditions, due to the pressure difference between the diaphragm on the lower and lower force, reach the purpose of cutting off the flow. The opening state of the solenoid valve - when the electric signal is given or the electromagnetic head is rotated manually by a remote controller, the drainage channel is opened, the water in the diaphragm is discharged, the pressure in the chamber is reduced, the pressure on the diaphragm is smaller, and the diaphragm moves upward under the pressure of the upstream, and the channel channel is opened. When the solenoid valve is closed, the drainage channel is closed manually or disconnected, the drainage channel is closed, and the diaphragm chamber is slowly filled with water. When the upper and lower pressure of the diaphragm is consistent, the diaphragm is moved downward and the pipeline channel is closed because of the larger force area on the upper side of the diaphragm. The single electric control only one electromagnetic head, after the electricity, the electromagnetic valve reversing, after the loss of electricity, the solenoid valve due to the effect of spring, double electric control 2 electromagnetic valves have 2 electromagnetic heads, only one of the electricity, after the electricity, the solenoid valve change, the electromagnetic valve position, the electromagnetic head must be in the other side, the solenoid valve back in situ.