The fluid in the piping must be consistent with the media selected in the solenoid valve series.
The temperature of the fluid must be less than the calibrated temperature of the selected solenoid valve.
Solenoid valve allows liquid viscosity is generally below 20CST, greater than 20CST should be noted.
Working pressure, the maximum pressure drop in the pipeline should be less than 0.04MPa, such as ZS, 2W, ZQDF, ZCM series and other direct-acting and step-by-step direct; the minimum working pressure greater than 0.04MPa can be used when the pilot The maximum working pressure should be less than the maximum calibration pressure of the solenoid valve; general solenoid valve are one-way work, so pay attention to whether there is anti-pressure, if installed check valve.
When the fluid cleanliness is not high, the filter should be installed before the solenoid valve. Generally, the solenoid valve requires better cleanliness of the medium.
Attention to the flow of holes and nozzle diameter; solenoid valve is generally only two control switch; conditions allow the installation of bypass pipe, easy maintenance; water hammer phenomenon to customize the solenoid valve opening and closing time adjustment.
Note the effect of ambient temperature on the solenoid valve
Power supply current and power consumption should be selected according to the output capacity, the power supply voltage is generally allowed to ± 10%, must pay attention to AC start VA value is higher.
Solenoid valve is divided into normally closed and normally open two; generally use normally closed type, power on, power off; but very long when the opening time is very short to use normally open type.
Life test, the factory is generally a type of test items, to say that China has no professional standard solenoid valve, so the choice of solenoid valve manufacturers when careful.
Action time is very short frequency is generally selected when the direct-type, large diameter selection of fast series.
General solenoid valve is not waterproof, when the conditions are not allowed to use waterproof type, the factory can be customized.
The maximum nominal pressure of the solenoid valve must exceed the maximum pressure in the pipe, otherwise the service life will be shortened or other accidents will occur.
Corrosive liquid should be selected all stainless steel type, strong corrosive fluid should use plastic king (SLF) solenoid valve.
Explosive environment must use the appropriate explosion-proof products.
Fourth, the economy
There are a lot of solenoid valve can be universal, but can meet the above three points should be based on the most economical products.
Principle of Structure of Solenoid Valve
First, direct-acting solenoid valve
There are two types of normally closed and normally open. Normally closed when the power is off when the state, when the coil power generated when the electromagnetic force, so that the core to overcome the spring force with the static core suction directly open the valve, the medium was channel; when the coil power loss when the electromagnetic force disappeared, moving iron The core under the action of the spring force to reset, directly close the valve port, the media barrier. Simple structure, reliable action, in the zero pressure and micro vacuum under normal work. Normally open the opposite. Such as less than φ6 flow path of the solenoid valve. (Figure 1 is a typical structure)
Second, the step-by-step direct solenoid valve
The valve is opened with a valve and the second valve in one, the main valve and pilot valve step by step so that the electromagnetic force and pressure directly open the main valve port. When the coil is energized, the electromagnetic force is generated so that the movable iron core and the static core are sucked and the pilot port is opened and the valve port is arranged on the main valve port, and the movable iron core is connected with the main spool, The pressure of the chamber through the guide valve unloading, in the pressure difference and electromagnetic force at the same time under the action of the main spool up movement, open the main valve medium circulation. When the coil power off when the electromagnetic force disappears, then move the core in the role of self-weight and spring force to close the valve hole, then the media in the balance hole into the main spool cavity, so that the upper chamber pressure, In the spring return and pressure under the effect of closing the main valve, the media flow. Reasonable structure, reliable action, working in zero pressure is also reliable. Such as: ZQDF, ZS, 2W and so on. (Figure 2 is a typical structure)
Third, indirect pilot solenoid valve
The series of solenoid valve by the pilot valve and the main valve core connected to form a combination of channels; normally closed in the absence of power, was off. When the coil is energized, the generated magnetic force causes the moving core and the static core to suck, the pilot port opens and the medium flows to the outlet. At this time, the pressure in the upper chamber of the main spool is reduced, which is lower than the pressure on the inlet side, Resistance and then move up to achieve the purpose of opening the main valve port, the media circulation. When the coil is powered off, the magnetic force disappears and the moving core is reset to close the pilot port under the action of the spring force. At this time, the medium flows from the balance hole, the upper chamber pressure increases and the spring force moves downward, Close the main valve port. The normally open principle is just the opposite. Such as: SLA, DF (φ15 above diameter), ZCZ and so on.