The use of pneumatic solenoid valves is increasing, so how to choose a suitable pneumatic solenoid valve? This article mainly introduces the selection of pneumatic solenoid valve and working conditions _ how to select the pneumatic solenoid valve (selection factor) _ pneumatic solenoid valve selection considerations, etc., to understand.
How to choose pneumatic solenoid valve (selection factor)1, operating torque
Operating torque is the most important parameter for selecting a pneumatic solenoid valve. The output torque should be 1.2 to 1.5 times the maximum torque of the valve operation.
2. Operating thrust
There are two kinds of mainframe structures, one is that the thrust disc is not arranged, and the torque is directly output at this time; the other is that the thrust disc is configured, and the output torque is converted into the output thrust through the stem nut in the thrust disc.
3, the number of output shaft rotation
The number of revolutions of the output shaft is related to the nominal diameter of the valve, the pitch of the valve stem, and the number of threads. It is calculated according to M=H/zs (in the formula: the total number of revolutions that the pseudo-electric actuator should satisfy; the opening of the assist valve Height, m; s is the pitch of the stem drive thread, mn; Z is the number of stem threads.)
4, stem diameter
For multi-turn type open-end valves, if the maximum stem diameter allowed by the pneumatic solenoid valve cannot pass through the valve stem of the valve, it cannot be assembled. Therefore, the inner diameter of the hollow output shaft must be larger than the stem of the open-end valve. path. For partial rotary valves and dark rod valves in multi-turn valves, this is not possible. Consider the problem of the diameter of the stem, but the diameter of the stem and the size of the keyway should be fully considered in the selection to make it work properly after assembly.
5, the output speed
The valve has a fast opening and closing speed and is prone to water hammer. Therefore, the appropriate opening and closing speed should be selected according to different conditions of use.
6, installation, connection method
Pneumatic solenoid valve installation methods are vertical installation, horizontal installation, floor installation; connection mode: thrust disc; valve stem through (bright multi-turn valve); dark rod multi-turn; no thrust disc; valve stem does not pass; Electric actuators are widely used and are indispensable for valve program control, automatic control and remote control. They are mainly used on closed-circuit valves. However, the special requirements of the valve electric actuator must not be neglected - it must be able to limit the torque or axial force. Usually the valve electric actuator uses a torque limiting coupling.
In the process of using the pneumatic solenoid valve, if it is improperly operated and used, the failure rate of the pneumatic solenoid valve will be large. Generally, the causes of malfunction of the solenoid valve type are incorrect installation, incorrect selection, actual operation, and improper use. The general failure is manifested by damage to the components of the solenoid valve. Pneumatic solenoid valve selection points and working conditions are as follows:
First, the media characteristics
1. Different types of solenoid valves are selected for the gas, liquid or mixed state;
2, the medium temperature is different specifications, otherwise the coil will burn out, the seals will age, seriously affecting the life expectancy;
3, the viscosity of the medium, usually below 50cSt. If this value is exceeded, the multi-function solenoid valve is used when the diameter is greater than 15 m; the high-viscosity solenoid valve is used when the diameter is less than 15 m.
4. When the medium cleanliness is not high, the recoil filter valve should be installed in front of the solenoid valve. When the pressure is low, the direct-acting diaphragm type solenoid valve can be used.
5. If the medium is directional and does not allow backflow, it needs to be circulated in both directions;
6, the medium temperature should be selected within the allowable range of the solenoid valve.
Second, the pipeline parameters
1. Select the valve port and model according to the medium flow direction requirements and pipe connection mode;
2. The nominal diameter is selected according to the flow rate and the kw value of the valve, and the inner diameter of the pipe can also be selected;
3. Working pressure difference: The minimum working pressure difference is above 0.04MP, which is optional indirect pilot type; the minimum working pressure difference is close to or less than zero, you must use direct-acting or step-by-step direct type.
Third, environmental conditions
1. The highest and lowest temperatures of the environment should be selected within the allowable range;
2. In the environment where the relative humidity is high and there are water droplets and rain, etc., the waterproof solenoid valve should be selected;
3, the environment often has vibration, bumps and impacts, etc. should choose special varieties, such as marine solenoid valves;
4. In the corrosive or explosive environment, the corrosion-resistant type should be selected according to the safety requirements.
5. If the environmental space is restricted, the multi-function solenoid valve should be selected because it eliminates the bypass and three manual valves and is convenient for online maintenance.
Fourth, the power supply conditions
1. According to the type of power supply, AC and DC solenoid valves are used respectively. Generally, AC power is convenient to use;
2, the voltage specification should be used as much as possible 8C2207.DC247;
3. The fluctuation of the power supply voltage is usually +%10%.-15% for AC, and about 10% for DC. If it is too poor, it must adopt voltage regulation measures;
4) The rated current and power consumption should be selected according to the power supply capacity. It should be noted that the YA value is higher when the AC starts, and the indirect-lead solenoid valve should be preferred when the capacity is insufficient.
Five, control accuracy
1. The ordinary solenoid valve can only open and close two positions. When the control precision is high and the parameter requirements are stable, multiple solenoid valves should be selected.
2. Action time: Refers to the completion time of the main signal action when the electric signal is turned on or off;
3. Leakage: The amount of leakage given on the sample is the common economic rating.
There are many types of solenoid valves, not only different brands, but also different models and types. Therefore, when selecting the type, it is necessary to select according to the specific needs, in order to maximize its performance. Then today, the first agent of imported solenoid valve dry ball automation and everyone talk about the selection of pneumatic solenoid valve.
First of all, it is necessary to consider the conditions of the power supply, because it is divided into many different types depending on the voltage. Instead, select the appropriate voltage based on the specific installation environment and needs. In addition, it should be noted that some are used for direct current, and some have AC power, so be sure to pay attention to the conditions of the power supply, select the appropriate model, which is the most critical when selecting this equipment.
Second, consider the environmental conditions applied to the pneumatic solenoid valve. In general, it is also the key to selection for the environment. Because the environment and temperature of different devices are very different. For example, if some humidity or rain will often be quiet, then you must choose a waterproof solenoid valve. If it is used in some high temperature environments, then the explosion-proof type should be selected, and if it is used in a corrosive environment, then the corrosion-resistant device should be selected.
Also pay attention to the accuracy of the pneumatic solenoid valve control. For example, the sensitivity of the control and the accuracy of the action time. These are all issues to consider, and for some environments, the accuracy requirements are critical. If the accuracy is not high, it is easy to cause some accidents. Therefore, we must pay attention to the selection according to the needs, select the high quality and device control accuracy, in order to ensure that the performance of the device can be more played out.
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