Function and structure principle of solenoid valve:

I. applicability

The fluid in the pipeline must be the same as the calibrated medium in the selected solenoid valve series.

The temperature of the fluid must be less than the calibration temperature of the selected solenoid valve. Solenoid valve allows liquid viscosity generally below 20CST, greater than 20CST should be noted. When the working pressure difference and the z high pressure difference of the pipeline are less than 0.04mpa, such as ZS,2W,ZQDF,ZCM series iso-direct acting type and step by step direct acting type should be selected; When z low working pressure difference is more than 0.04mpa, pilot type (pressure difference type) solenoid valve can be selected; The z high working pressure difference should be less than the z big calibration pressure of the solenoid valve; General solenoid valve is one-way work, so pay attention to whether there is a back pressure difference, such as the installation of check valves.

Fluid cleanliness is not high should be installed in front of the solenoid valve filter, liquid gas solenoid valve on the medium requirements of cleanliness. Pay attention to flow aperture and nozzle diameter; Solenoid valve generally only switch two control; If possible, please install the bypass pipe for easy maintenance. When there is water hammer phenomenon to customize the solenoid valve opening and closing time adjustment. Note the influence of ambient temperature on the solenoid valve: the power supply current and consumed power should be selected according to the output capacity. The power supply voltage is generally allowed to be about ±10%.

Ii. Reliability

Solenoid valve is divided into normally closed and normally open two kinds; Normally closed type, power on, power off; But in the open for a long time to close very short to choose the normally open.

Life test, the factory generally belongs to the type test project, to be exact, there is no professional standard of solenoid valve in our country, so choose solenoid valve manufacturers carefully.

When the movement time is very short and the frequency is high, the direct movement type is generally selected and the fast series is used for large caliber.

Iii. Safety

General solenoid valve is not waterproof, when the condition is not allowed to choose waterproof, the factory can be customized. The z high calibration nominal pressure of the solenoid valve must exceed the z high pressure in the pipeline, otherwise the service life will be shortened or other unexpected circumstances. Corrosive liquid should be all stainless steel type, strongly corrosive fluid should be plastic king (SLF) solenoid valve. Explosive environment must choose the corresponding explosion-proof products.

Iv. Economy

There are a lot of solenoid valves can be used, but on the basis of the above three points should be used z economic products.

Structural principle of solenoid valve　

Direct acting solenoid valve

There are two types: normally closed and normally open. Normally closed mode is closed when the power is cut off. When the coil is energized, electromagnetic force is generated to make the moving iron core overcome the spring force and directly open the valve with the static iron core. When the coil power off, the electromagnetic force disappeared, the moving iron core under the action of spring force reset, directly close the valve mouth, media impenetrable. Simple structure, reliable operation, normal operation under zero pressure difference and micro vacuum. Normally open is just the opposite. Such as less than 6 flow diameter of the solenoid valve.

Step by step direct acting solenoid valve

The valve USES the primary valve and the secondary valve in one body, the main valve and the guide valve step by step so that the electromagnetic force and pressure difference directly open the main valve mouth. When energized coil, thus moving iron core and static iron core and electromagnetic force, pilot valve is located in the main valve and pilot valve mouth mouth open mouth, and the moving core and the main valve core together, at this time the main valve cavity pressure on the unloading, through the pilot valve port under the action of pressure difference and the electromagnetic force at the same time the main valve core upward movement, open the main valve medium circulation. When the coil is cut off, the electromagnetic force disappears. At this point, the moving iron core closes the guide valve hole under the action of dead weight and spring force. At this point, the medium enters into the upper chamber of the main valve core in the balance hole, increasing the pressure of the upper chamber. Reasonable structure, reliable operation and reliable operation at zero differential pressure. Such as: ZQDF, ZS, 2W, etc.　

Indirect pilot solenoid valve

The series of solenoid valve by the pilot valve and the main valve core connected to form a channel combination; Normally closed mode is closed when not energized. When the coil is energized, the magnetic force generated makes the moving iron core and the static iron core attract and close, the guide valve mouth opens, and the medium flows to the outlet. At this time, the pressure in the cavity of the main valve core decreases, which is lower than the pressure on the inlet side. The pressure difference is formed to overcome the spring resistance and move upward accordingly, so as to open the main valve mouth and circulate the medium. When the coil power off, the magnetic force disappeared, the moving iron core under the action of spring force reset to close the pilot mouth, at this time the medium from the balance hole into the main valve core, the pressure on the cavity increased, and under the action of spring force downward movement, close the main valve mouth. The normally open principle is just the opposite. Such as: SLA, DF (15 + caliber), ZCZ, etc.