What is the function of solenoid valve? Solenoid valve icon symbol

First of all, both pneumatic and hydraulic sub-industries use the valves mentioned above. Secondly, pneumatic and hydraulic systems are generally divided into gas and liquid sources and processing systems, control components, and execution components. The various valves mentioned above are all control components. As the name suggests, it is to control various media or parameters of the gas and liquid system. Nothing more than direction, flow, pressure, etc. These valves above play this role.

Let’s talk about the directional control valve first. As the name suggests, it controls the direction of the fluid. The reversing valve and one-way valve you mentioned are both directional control valves. Directional valves are almost all pneumatic and hydraulic components with the largest variety, the largest total volume, and relatively speaking, they are the most concerned type of component. The two-position two-way, two-position three-way, three-position five-way, etc. that we often hear are all directional control valves. The overflow valve is a pressure control valve, which means that after the pressure reaches or exceeds a certain set value, the gas flows out from the overflow port to protect the system pressure.

Proportional valves and servo valves classify valves from another dimension. For example, a flow proportional valve automatically and steplessly adjusts the flow of the valve, and the input current signal has a certain proportional relationship with the output gas flow. This is very different from traditional valves. Servo valves are used in servo control systems to improve the response speed of the system. These two valves include pressure control valves and flow control valves. Proportional valves and servo valves are much more expensive than traditional electromagnetic direction and pressure control valves, and are rarely used in the general automation industry.



What is the function of solenoid valve? The solenoid valve is a stop valve that relies on electromagnetic force to automatically open and close. In refrigeration and air conditioning equipment, solenoid valves are commonly used as remote control stop valves, adjustment mechanisms of two-position adjustment systems, or safety protection equipment. It can be used as a remote control stop valve, a regulating mechanism of a two-position regulating system or a safety protection device using a magnetic valve. It can be applied to various gases, liquid refrigerants, lubricating oil and other media.

For some early small and medium-sized unit units, the solenoid valve is connected in series on the liquid pipe in front of the throttling device, and is connected to the same start switch as the compressor. When the compressor is turned on, the solenoid valve opens and the system pipeline is connected to allow the air conditioning system to operate normally. When the compressor stops, the solenoid valve automatically cuts off the liquid pipeline to prevent the refrigerant liquid from continuing to flow to the evaporator and prevent refrigerant liquid shock when the compressor is started again.

In central air conditioning (multi-split) systems, solenoid valves are more widely used in the system, including: pilot valves that control four-way valves, compressor exhaust oil return lines, cooling circuits, etc.

The function of vacuum solenoid valve

The vacuum solenoid valve acts in the pipeline system and can use electromagnetic principles to achieve vacuum treatment of the pipeline and realize electromagnetic control at the same time. It can have a great impact on the entire working state of the pipeline system, and the use of vacuum solenoid valves can also effectively Avoid the impact of other irrelevant factors on the pipeline, so as to make correct adjustments to the working status of the pipeline system.

Solenoid valve symbol






The meaning of solenoid valve graphic symbols:
1. Use boxes to represent the working position of the valve. Each box represents a working position of the solenoid valve, that is, a "position". The number of boxes indicates the number of "positions", such as the two-position three-way solenoid valve. There are two working positions.
2. The arrow in the box indicates that the oil circuit is connected, but the direction of the arrow does not necessarily indicate the actual direction of the liquid flow;
3. The symbols “┻” or “┳” in the box indicate that the path is unavailable;
4. The number of interfaces connected to the outside of the box indicates how many "connections" there are;
5. Generally, the oil inlet/air inlet connecting the valve to the system oil supply line or gas line is represented by the letter p;the oil return/air return port connecting the valve to the system oil return line/gas line is represented by t (sometimes o is used) represents;and the oil port/air port connecting the valve and the actuator is represented by a, b, etc. Sometimes l is used on the graphic symbol to represent the leakage port;
6. The reversing valve has two or more working positions, one of which is the normal position, that is, the position of the valve core when it is not subject to control force. The middle position in the graphic symbol is the normal position of the three-position valve. The two-position valve that uses a spring to return the valve takes the passage state in the box close to the spring as its normal position. When drawing a system diagram, the oil/gas circuit should generally be connected to the normal position of the reversing valve.