Solenoid valve is an industrial equipment controlled by solenoids, and is a basic element of automation used to control fluids, which belongs to actuators and is not limited to hydraulics and pneumatics. It is used in industrial control systems to adjust the direction, flow rate, speed and other parameters of the medium. Solenoid valves can be combined with different circuits to achieve the desired control, and the accuracy and flexibility of the control can be guaranteed. There are many kinds of solenoid valves, and different solenoid valves play a role in different positions of the control system, and the most commonly used ones are check valves, safety valves, directional control valves, speed control valves, etc.
Solenoid valves can be divided into three categories in principle: direct-acting, step-by-step direct-acting, and pilot-operated.
There are two types: normally closed type and normally open type. When the coil is energized, electromagnetic force is generated, so that the moving iron core overcomes the spring force and engages with the static iron core to open the valve directly, and the medium is in a path; When the coil is powered off, the electromagnetic force disappears, and the moving iron core is reset under the action of spring force, and the valve port is closed directly, and the medium is blocked. The structure is simple, the action is reliable, and it works normally under zero pressure difference and micro vacuum. The normal type is the opposite. Such as solenoid valves with a flow diameter of less than φ6.
Principle: When the normally closed type is energized, the electromagnetic coil generates electromagnetic force to lift the open part from the valve seat and open the valve; When the power is off, the electromagnetic force disappears, the spring presses the opening on the valve seat, and the valve is open. (Normally open type is the opposite)
Features: It can work normally under vacuum, negative pressure and zero pressure, but the diameter is generally not more than 25mm.
This kind of valve adopts a single opening valve and a secondary opening valve in one, and the main valve and the pilot valve make the electromagnetic force and pressure difference directly open the main valve port step by step. When the coil is energized, the electromagnetic force is generated to make the moving iron core and the static iron core engage, the pilot valve port is opened and the pilot valve port is located on the main valve port, and the moving iron core is connected with the main valve core together, the pressure of the upper cavity of the main valve is unloaded through the pilot valve port at this time, and the main valve core moves upward under the simultaneous action of pressure difference and electromagnetic force, and the main valve medium flow is opened. When the coil is de-energized, the electromagnetic force disappears, at this time the moving iron core closes the pilot valve hole under the action of its own weight and spring force, and the medium enters the upper cavity of the main valve core in the balance hole at this time, so that the pressure of the upper cavity rises, and the main valve is closed under the action of spring return and pressure, and the medium is cut off. The structure is reasonable, the action is reliable, and the work is also reliable when the pressure difference is zero.
Principle: When energized, the electromagnetic force opens the pilot hole, the pressure of the upper chamber drops rapidly, and a low and high pressure difference is formed around the closing piece, and the fluid pressure pushes the closing part to move upward, and the valve is opened; When the power is off, the spring force closes the pilot hole, and the inlet pressure quickly forms a low and high pressure difference around the closing valve through the bypass hole, and the fluid pressure pushes the closing part to move down and close the valve.
Features: small size, low power, high upper limit of fluid pressure range, can be installed arbitrarily (need to be customized) but must meet the fluid pressure difference conditions.
Solenoid valves are divided into six sub-categories from the differences in valve structure and material and the difference in principle:
Direct-acting diaphragm structure, step-by-step direct-acting diaphragm structure, pilot diaphragm structure, direct-acting piston structure, step-by-step direct-acting piston structure, pilot piston structure.
Solenoid valves are classified according to function:
Water solenoid valve, steam solenoid valve, refrigeration solenoid valve, cryogenic solenoid valve, gas solenoid valve, fire solenoid valve, ammonia solenoid valve, gas solenoid valve, liquid solenoid valve, miniature solenoid valve, pulse solenoid valve, hydraulic solenoid valve, normally open solenoid valve, oil solenoid valve, DC solenoid valve, high pressure solenoid valve, explosion-proof solenoid valve, etc.
|
More on that
|
Maintenance method of safety valve - Wuzhong instrument
1. The safety valve should have the equipment to prevent the hammer from moving by itself and the guide frame to restrain the lever from deviating, and the tension spring safety valve should have the equipment to improve the handle and prevent the adjustment screws from being twisted at will.
2. It should be installed straight in the pot merchant, the container ...
|
|
Key points of classification and selection of cryogenic valves - Wuzhong instrument
Cryogenic valves are mainly used in ethylene, liquefied natural gas units, air separation equipment, petrochemical tail gas separation equipment, liquid oxygen, liquid nitrogen, liquid argon, carbon dioxide cryogenic storage tanks and tankers, pressure swing adsorption oxygen production devices, etc., the main varieties are cryogenic ball valves, cryogenic globe valves, etc.
...
|
|
Indicates the classification of instruments and their advantages and disadvantages
The mechanical deflection angle of the movable part of the surface can be measured and converted, and the size to be measured is directly indicated by the indicator, so it is also called the direct-reading appearance.
According to the working principle, the indication surface can be divided into magnetoelectric system appearance, electromagnetic system appearance, electric system appearance and ...
|
|
Wuzhong instrument A2000 axial flow valve features
1. The valve core is pressure balanced, even if the large-diameter valve is under the high pressure drop parts, it can also be operated with a smaller actuator.
2. The inner cavity of the valve is straight-through streamlined, which greatly reduces the activity resistance.
3. The concentric movement method of the valve core and the valve body is greatly ...
|
|
Problems and solutions of pneumatic butterfly valves - Wuzhong instrument
1. The signal valve pushed by the control box does not move. Under the condition that the positioner is installed, the pneumatically adjustable butterfly valve is equipped with a solenoid valve. The weak current of the solenoid valve affects the information output of the control box, and the valve cannot withstand the data signal and cannot work normally.
...
|
|
Valve actuator type - Wuzhong instrument
There are currently four types of actuators, which are capable of operating various types of valves with different driving forces.
1. Electric multi-reverse executive organization
Electrically driven multi-reversal executive organizations are one of the most commonly used and reliable types of executive organizations. Wield...
|
|
Wuzhong instrument control valve knowledge
The actuator of the control valve has pneumatic type, electric type and electro-hydraulic linkage type, and the pneumatic equipment is divided into barrier type and cylinder type. Depending on the action when the operating signal and the drive source disappear, the actuator has a forward type, a reverse type, a non-directional type, and a persistent type. The positive type is used in the operation signal and drive ...
|
|
Precautions for valve installation - Wuzhong instrument
1. Before the device, check whether the valve has notched parts, whether the type is correct, whether there are debris in the valve body, and whether the muffler is blocked.
2. Close the valve and cylinder.
3. Device the cylinder on the valve, the direction of the equipment is parallel or straightened with the valve body, and check whether the screw holes are aligned.
|
|
The use of butterfly valves - Wuzhong instrument
Selection:
The butterfly plate of the butterfly valve is installed in the diameter direction of the pipe. The butterfly valve has a simple structure, small size, light weight, only a few parts, and only needs to rotate 90° to quickly open and close, the operation is simple, and the ...
|
|
Briefly describe the knowledge of instrument valves
Valves are the most common equipment in chemical enterprises and play a great role. They seem to be simple and easy, but in the actual operation process, they also need to meet the relevant technical requirements, otherwise they will cause safety accidents. Only the valves related to our liquid level appearance are introduced here, and other equipment is not analyzed. ...
|
|
Detection instrument (component) and control valve selection principle - Wuzhong instrument
1. High-precision operation, can complete rapid palletizing and destacking operations.
(1). The conditions of the process
Factors such as temperature, pressure, flow, viscosity, corrosiveness, toxicity, pulsation and other factors in the process determine the appearance of the ...
|
|
Pneumatic valve fault location analysis - Wuzhong instrument
In the process of use, several problems are usually presented in the direction of (FO, FC, FL), and the "fault" in the valve fault closing/obstacle opening refers to: the action of the valve when the gas source is gone. For the fault location of pneumatic valves, it is mainly divided into several situations:
...
|
|
The material and connection method of the valve - Wuzhong instrument
Valves are control components in fluid transportation systems, which have the functions of shut-off, regulation, diversion, prevention of backflow, pressure stabilization, diversion or overflow pressure relief. Valves for fluid control systems, from the simplest shut-off valves to the most complex valves used in automated control systems, are available in a variety and size.
|
|
Valve positioner classification - Wuzhong instrument
1. The valve positioner is divided into pneumatic valve positioner, electrical valve positioner and intelligent valve positioner according to the input signal.
(1) The input signal of the pneumatic valve positioner is a standardized gas signal, for example, the 20-100kPa gas signal, and its output signal is also a standardized gas signal. （ ...
|
|
Wuzhong instrument control valve components
1. Valve body assembly
The valve body assembly shall have the following elements: structural type, nominal diameter, nominal pressure, connection type with pipeline, applicable temperature scale, raw materials of valve body and internals, valve seat diameter or rated flow coefficient, flow characteristics, valve seat leakage grade, etc.
...
|
|
The working principle of valve limit switch box detection - Wuzhong instrument
The angular displacement of the valve position detected by the valve limit switch box changes the transmission shaft through the coaxial adjacency or the reaction rod, so that the cam touches the miniature switch, so that the contact of the switch assembly is closed or disconnected, and the switching signal is transmitted to the outside through the terminal, and the passer is displayed on the spot.
...
|
|
Solenoid valve installation precautions
1. Before the equipment, you should carefully read the operation manual of the product, check whether the product can fully meet the application needs, understand the key to the equipment, and prepare for the operation.
2. Check whether the parameters marked on the nameplate can be the parameters of the selected product and whether they can be consistent with the instructions.
3. Acceptance ...
|
|
Precautions for the installation and use of electric control valve - Wuzhong instrument
1. The hydraulic power in the hydraulic ball valve should refer to the opening mode of the valve as hydraulic, which refers to the valve opening device. The latter ball valve refers to the valve type as a valve type and a shut-off valve class.
Two: Type Q61N can explain Q as ...
|
|
Wuzhong Instrument G2010 long-distance pipeline ball valve use structure characteristics and analysis
G2010 ball valve for long-distance pipeline is designed for the transportation of long-distance pipeline media, which is a typical long-distance pipeline ball valve, which is suitable for various oil, natural gas, city gas pipelines, and can also be used in the equipment of general chemical products. The valve is completely in line with the United States Petroleum Institute API in terms of performance...
|
|
Structural requirements for thermocouples in Wuzhong instruments
The structure of the thermocouple is to ensure the stable operation of the thermocouple, and the requirements are as follows:
The two thermoelectrodes that make up the thermocouple must be strong on the weld to maintain good quality.
|
|
Contact
working hours
