Knowledge

What is a solenoid valve



Solenoid valves are automated basic components used to control the direction of fluids. They are actuators; they are typically used on mechanical controls and industrial valves to control the direction of the media to achieve control of the valve switches.

working principle
There are closed chambers in the solenoid valve. There are through holes in different positions. Each hole leads to different oil pipes. The middle of the cavity is a valve. On both sides are two electromagnets. Which side of the magnet coil is energized and the valve body will be attracted. On which side, by controlling the movement of the valve body to block or leak different oil drain holes, and the oil inlet hole is normally open, the hydraulic oil will enter different oil drain pipes, and then the oil pressure will push the oil cylinder. The piston, which in turn drives the piston rod, drives the mechanical device. This controls the mechanical motion by controlling the current through and off of the electromagnet.

New multi-function solenoid valve:
Installation pipeline: It has a manual function, eliminating three manual valves and can be repaired online, which greatly reduces the cost.
1. The applicable range of medium viscosity is adjustable: the adjustment can realize the general use of gas, water and oil, and is convenient for purchasing, storage, installation and maintenance.
2. The valve opening and closing time is adjustable: it can meet various requirements and effectively prevent water hammer damage.
3, the valve opening can be adjusted: the maximum and minimum opening can be preset to improve the accuracy of automatic control.
4, the main valve wear can compensate:: extend the service life of the valve, withstand long-term test.
Structural principle
The valve skillfully combines the first conductive magnetic valve, the manual valve and the throttle valve, and the pilot valve receives the electric signal switch to drive the main valve. Adjustment screws A and B adjust the medium viscosity range and main valve switching time and can be compensated after the main valve wears. When the pilot valve needs to be repaired, just tighten the adjusting screw B and the isolating screw C, and then remove it and use the manual screw. The screw can also be used to preset the maximum or minimum flow rate when the solenoid valve is automatically controlled.

classification
1. Solenoid valves are divided into three main categories in principle:
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 is opened; when the power is off, the electromagnetic force disappears, the spring presses the closing member against the valve seat, and the valve is closed.
Features: It can work normally under vacuum, negative pressure and zero pressure, but the diameter is generally not more than 25mm.
2) Step-by-step direct-acting solenoid valve:
Principle: It is a combination of direct motion and pilot type. When there is no pressure difference between the inlet and the outlet, after energization, the electromagnetic force directly lifts the pilot small valve and the main valve closing member upward, and the valve opens. When the inlet and outlet reach the starting pressure difference, after the energization, the electromagnetic force leads the small valve, the pressure of the lower chamber of the main valve rises, and the pressure of the upper chamber drops, so that the main valve is pushed upward by the pressure difference; when the power is off, the pilot valve uses the spring The force or medium pressure pushes the closure and moves down to close the valve.
Features: It can also be operated at zero differential pressure or vacuum or high pressure, but the power is large and requires horizontal installation.
3) Pilot solenoid valve:
Principle: When energized, the electromagnetic force opens the pilot hole, the pressure in the upper chamber drops rapidly, and a pressure difference between the upper and lower parts is formed around the closing member. The fluid pressure pushes the closing member upward and the valve opens. 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 low 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, it can be installed arbitrarily (customized), but the fluid pressure difference condition must be met.
2. The difference between the solenoid valve from the valve structure and material and the principle is divided into six sub-categories:
Direct-acting diaphragm structure, step-by-step direct diaphragm structure, pilot diaphragm structure, direct-acting piston structure, step-by-step linear motion piston structure, pilot piston structure.