Solenoid valve

Contact the solenoid valve manufacturer directly to request samples

I wonder whether the poster wants to import it or get a domestic version? Are there specific parameters? I can help you choose the right model!

Looking at solenoid valves both domestically and internationally, to date they can be divided into three main categories based on their operating mechanism: direct-acting, recoil-type, and pilot-operated. Furthermore, due to differences in the structure and material of the valve disc as well as variations in their working principles, the recoil-type valves can be further divided into diaphragm-type recoil solenoid valves and piston-type recoil solenoid valves； Pilot-operated types can be further divided into: pilot-operated diaphragm solenoid valves and pilot-operated piston solenoid valves ； Based on the valve seat and sealing material, they can be further classified into: soft-sealing solenoid valves, rigid-sealing solenoid valves, and semi-rigid-sealing solenoid valves. I. Direct-acting solenoid valve Principle: In a normally closed direct-acting solenoid valve, when power is applied, the electromagnetic coil generates an electromagnetic force that lifts the valve core, causing the closing element to move away from the valve seat and thus opening the seal ； When power is cut off, the electromagnetic force disappears, and the spring force presses the closing element against the valve seat, thereby closing the valve. (Contrary to normally open types) Feature: It can operate properly in vacuum, negative pressure, or zero pressure difference. It can be installed in sizes up to DN50, but the solenoid head is relatively large in size. The direct-acting solenoid valves produced by our company using HERION’s technology can be used in vacuums of 1.33×10-4 Mpa. II. Recoil-type solenoid valve: Principle: It operates through a combination of direct action and pilot operation. When electricity is applied, the solenoid valve first opens the auxiliary valve; the pressure in the lower chamber of the main valve is higher than that in the upper chamber, and it is this pressure difference together with the action of the solenoid valve that causes the valve to open ； When power is lost, the auxiliary valve uses spring force or medium pressure to push the closing element downward, thereby closing the valve. Features: It can operate reliably even at zero pressure difference or high pressure, but it has high power consumption and a large size, requiring vertical installation. III. Pilot-operated solenoid valve: When electricity is applied, electromagnetic force drives the pilot valve to open; this causes the pressure in the upper chamber of the main valve to drop rapidly, creating a pressure difference between the upper and lower chambers of the main valve. The pressure of the medium then pushes the closing element of the main valve upward, thereby opening the valve ； When power is lost, the spring force closes the pilot valve; the pressure of the incoming medium enters the upper chamber of the main valve through the pilot holes, creating a pressure difference in that chamber which in turn causes the main valve to close. Features: Small size and low power, but the range of medium pressure differences is limited; pressure difference requirements must be met. Two-position three-way solenoid valves are typically used in conjunction with single-acting pneumatic actuators. The two-position aspect means that there are two controllable states: on-off. The three-way design features three channels for air flow; generally, one of these channels is connected to the air supply, while the other two channels are connected—one to the air inlet of the actuator and the other to its air outlet. For more details on how they work, refer to the schematic diagram of a single-acting pneumatic actuator. Two-position five-way solenoid valves are typically used in conjunction with double-acting pneumatic actuators. The \"two-position\" aspect means that there are two controllable states: open and closed. The \"five-way\" feature refers to the presence of five channels for airflow; one of these channels is connected to the air supply, two are connected to the inlet and outlet ports of the external air chamber of the double-acting cylinder, and two are connected to the inlet and outlet ports of the internal air chamber. For more details on how they work, refer to the operating principle of double-acting pneumatic actuators. In terms of the air (or fluid) circuit, a two-position three-way solenoid valve has one inlet port (for connecting to the air supply), one outlet port (to supply air to the device in question), and one exhaust port (a silencer is usually installed at this port; it can be omitted if noise is not a concern @_@). The two five-way solenoid valves have 1 intake port (connected to the air supply), 1 exhaust port for forward operation and 1 exhaust port for reverse operation (providing air supply for forward and reverse actions to the target device respectively), 1 exhaust port for forward operation and 1 exhaust port for reverse operation (equipped with silencers). For small automatic control devices, industrial rubber air hoses with a diameter of 8~12 mm are generally used for the air supply lines. Electrically, two-position three-way solenoid valves are generally single-electrode controlled (i.e., with a single coil), while two-position five-way solenoid valves are generally double-electrode controlled (i.e., with two coils). The coil voltage levels are generally DC24V, AC220V, etc. Two-way three-port solenoid valves are divided into two types: normally closed and normally open. A normally closed valve means that the air path is closed when the coil is not powered, while a normally open valve means that the air path is open when the coil is not powered. Operating principle of the normally closed two-position three-way solenoid valve: When power is supplied to the coil, the air path is opened; once the power to the coil is cut off, the air path is closed, which is equivalent to a \"momentary\" operation. Operating principle of the normally open two-position three-way single-electrovalve solenoid valve: When power is supplied to the coil, the air path is closed; once the power to the coil is cut off, the air path is opened. This is what is referred to as \"momentary operation\". Operation principle of the two five-way dual-electric-control solenoids: When power is supplied to the forward-action coil, the forward-action air path is connected (air flows out from the forward-action outlet); even after the power to the forward-action coil is cut off, the forward-action air path remains connected, and this state will persist until power is supplied to the reverse-action coil. When power is supplied to the reverse action coil, the reverse action air circuit is activated (air flows out of the reverse action exhaust port). Even after the power to the reverse action coil is cut off, the reverse action air circuit remains active, and this state will persist until power is supplied to the forward action coil. This is equivalent to “self-locking”. Taking into account these characteristics of the two-position five-way dual-electronic control solenoid valves, when designing the electromechanical control circuit or writing PLC programs, it is sufficient to allow the solenoid coil to operate for 1–2 seconds; this helps to prevent the solenoid coil from being damaged. Solenoid valves are used in hydraulic systems to enable the opening and closing of fluid pathways or to change the direction of fluid flow. They typically consist of a valve core that can slide under the action of electromagnetic force; depending on the position of this valve core, the flow path of the solenoid valve changes as well. There are several working positions for the valve core, and the solenoid valve is accordingly referred to as a solenoid valve with that number of positions. The number of connections on the valve body, that is, the number of passages in the solenoid valve, determines whether it is called a one-way solenoid valve, a two-way solenoid valve, and so on. After the solenoid valve is installed, all connections should generally be in place; the so-called operating position refers to the position of the valve core. When the coil is not powered, the valve core is in position A; when the coil is powered, it is in position B. Depending on its position, the valve core either connects or blocks various interfaces. Two-position for a solenoid valve means that the valve element of the solenoid valve has two distinct operating positions (open, closed). Two-way and three-way solenoid valves refer to solenoid valves that have two or three port openings on their valve body ； For example, a two-position two-way solenoid valve has one inlet and one outlet (two channels; the most common type). A two-position three-way solenoid valve used to control liquids has one inlet and two outlets (one of the outlets is normally open while the other is normally closed) ； The pneumatic directional solenoid valve has one inlet, one outlet, and an exhaust port ； Hydraulic: one inlet, one outlet, and one return. Solenoids, both domestic and international, can be classified into three main categories based on their principle of operation (i.e., direct-acting, step-by-step direct-acting, and pilot-operated). Depending on differences in valve disc structure, materials, and operational principles, they are further divided into six subcategories (direct-acting diaphragm structure, step-by-step diaphragm structure, pilot-operated diaphragm structure, direct-acting piston structure, step-by-step direct-acting piston structure, and pilot-operated piston structure). Direct-acting solenoid valve: Principle: When electricity is applied, the electromagnetic coil generates an electromagnetic force that lifts the closing element away from the valve seat, thereby opening the valve ； When power is cut off, the electromagnetic force disappears, and the spring presses the closing element against the valve seat, causing the valve to close. Features: It can operate normally under vacuum, negative pressure, and zero pressure, but the diameter generally does not exceed 25 mm. Direct-acting solenoid valve: Principle: It operates on a combination of direct-acting and pilot-operated mechanisms; when there is no pressure difference between the inlet and outlet, upon power application, the electromagnetic force lifts the pilot valve and the main valve’s closing element upward one after another, thereby opening the valve. When the pressure difference between the inlet and outlet reaches the starting value, upon power application, the electromagnetic force acts on the pilot valve; as a result, the pressure in the lower chamber of the main valve rises while the pressure in the upper chamber drops, and this pressure difference is used to push the main valve upward ； During a power outage, the pilot valve uses spring force or medium pressure to push the closing element downward, thereby closing the valve. Features: It can operate at zero pressure difference or in vacuum as well as under high pressure, but it requires a higher power level and must be installed horizontally. Pilot-operated solenoid valve: Principle: When electricity is applied, electromagnetic force opens the pilot hole, causing the pressure in the upper chamber to drop rapidly. This creates a pressure difference with higher pressure below and lower pressure above the closing element; the fluid pressure then pushes the closing element upward, opening the valve ； When power is lost, the spring force closes the pilot hole; the inlet pressure passes through the bypass hole, creating a pressure difference in the chamber such that the pressure is lower at the bottom and higher at the top around the valve closing element. The fluid pressure then pushes the closing element downward, thereby closing the valve. Features: It has a high upper limit for fluid pressure; it can be installed in any position (customization is required), but the fluid pressure difference conditions must be met. Some insights into solenoid valves in practical applications: Solenoid valves are widely used in our production processes, and we have certainly encountered many issues related to them during maintenance tasks, as well as dealt with various types of faults. Everyone must have accumulated considerable experience in handling solenoid valve-related problems. Personally, I have dealt with fewer solenoid valve faults compared to other instrument control-related issues. Now I would like to discuss this topic with everyone, hoping to learn more from you all in order to improve together. Let’s first get a basic understanding of solenoid valves. A solenoid valve consists of an electromagnetic coil and a magnetic core, along with a valve body that contains one or several holes. When the coil is energized or de-energized, the movement of the magnetic core causes the fluid to pass through or be blocked by the valve body, thereby changing the direction of the fluid. The electromagnetic component of the solenoid valve consists of a fixed core, a moving core, a coil, and other components ； The valve body part consists of a spool, a spool sleeve, a spring base, etc. The electromagnetic coil is directly mounted on the valve body, which is enclosed in a sealed tube, forming a simple and compact assembly. The solenoid valves commonly used in our production include 2/3-way, 2/4-way, 2/5-way, etc. Let’s first explain what these two terms mean: for solenoid valves, they refer to being energized and de-energized; for the valves they control, they refer to being open and closed. In our oxygen generator control system, two-position three-way solenoid valves are the most commonly used; they can be employed in production to connect or disconnect the gas supply, thereby switching the air paths for pneumatic control diaphragms. It consists of components such as a valve body, a valve cover, an electromagnetic assembly, springs, and sealing structures; the sealing block at the bottom of the moving iron core closes the air inlet of the valve body under the pressure of the springs. When powered on, the electromagnet attracts, and the spring-loaded sealing block at the upper part of the moving core closes the exhaust port; air flows in through the inlet port to the diaphragm head, thereby serving a control function. When there is a power loss, the electromagnetic force disappears; the moving core moves away from the fixed core under the action of the spring force, moving downward to open the exhaust port and block the intake port. The air flow from the diaphragm passes through the exhaust port, and the diaphragm returns to its original position. In our oxygen production equipment, it is used in places such as the emergency shut-off valve at the inlet of the turbine expander diaphragm valve. SiTong solenoid valves are also widely used in our production. Their working principle is as follows: When an electric current flows through the coil, an excitation effect is generated, causing the fixed core to attract the moving core. The moving core then drives the slide valve core and compresses the spring, thereby changing the position of the slide valve core and thus altering the direction of the fluid flow. When the coil loses power, the elastic force of the spring pushes the spool core, pushing back the moving core and allowing the fluid to flow in its original direction. In our oxygen production process, the operation of the relief valve in the molecular sieve switching system is controlled by a two-position four-way solenoid valve, with air flow being supplied to both ends of the piston of the relief valve. Thereby controlling the opening and closing of the relief valve. Malfunctions of solenoid valves will directly affect the operation of switch valves and control valves. Common faults include the solenoid valve not functioning, and troubleshooting should be carried out from the following aspects: (1) The wiring connections of the solenoid valve are loose or the wires have come loose, resulting in no power reaching the solenoid valve; in such cases, the wires can be tightened. (2) If the solenoid coil is damaged, the wiring of the solenoid can be removed and measured with a multimeter; if there is an open circuit, then the solenoid coil is damaged. The reason is that moisture gets into the coil, leading to poor insulation and magnetic leakage, which results in excessive current flowing through the coil and causing it to burn out; therefore, it is necessary to prevent rainwater from entering the solenoid valve. Furthermore, an overly stiff spring, excessive reaction force, too few turns of wire, and insufficient suction can also cause the coil to burn out. In emergency situations, the manual button on the coil can be switched from the “0” position used during normal operation to the “1” position, thereby opening the valve. (3) The solenoid valve is stuck. The clearance between the spool sleeve of the solenoid valve and the valve core is very small (less than 0.008 mm); it is usually assembled as a single unit. When mechanical impurities get in or there isn’t enough lubricating oil, jamming can easily occur. The solution is to insert a steel wire through the small hole at the head to make it bounce back. The fundamental solution is to remove the solenoid valve, take out the spool and its sleeve, and clean them with CCI4 so that the spool can move freely within the sleeve. When disassembling, pay attention to the assembly sequence of the various components as well as the locations of the external wiring, so as to ensure proper reassembly and wiring. Also, check whether the oil mister nozzles are clogged and whether there is sufficient lubricating oil. (4) Air leakage. Air leakage can lead to insufficient air pressure, making it difficult for the check valve to open and close; this is caused by damaged gaskets or worn spools, which result in air leaking between various chambers. When dealing with faults in the solenoids of a switching system, it is necessary to choose the right moment to carry out repairs – wait until the solenoid is de-energized. If the repairs cannot be completed within one switching interval, the switching system can be paused to allow for proper handling of the issue. Pasted from another section; hope it’s useful to you

Solenoid valve selection should follow the four principles of safety, reliability, suitability, and cost-effectiveness, as well as six requirements related to field conditions (i.e., diameter, type of medium, pressure level, power supply voltage, operating mode, and special functions). II. Selection of solenoid valves based on the type of medium: valve body material, sealing material, temperature range. 1. For corrosive fluids: the valve body material should be stainless steel or PTFE (polytetrafluoroethylene, commonly known as \"plastic king\"), with fluororubber or PTFE used as the sealing material. 2. Food-grade or ultra-pure fluids: The valve body should be made of sanitary-grade stainless steel, with silicone rubber used as the sealing material. 3. High-temperature fluids: Electromagnetic valves made from high-temperature resistant electrical and sealing materials should be selected, and those with a piston-type design principle should be chosen as well. 4. Fluid state: It can be gaseous, liquid, or in a mixed state; in particular, when the diameter is greater than 25, it is necessary to distinguish between these states, as it is related to the parameters of the guide hole. 5. Fluid viscosity: It can generally be chosen arbitrarily as long as it is below 50 cSt; if it exceeds this value, a high-viscosity solenoid valve must be used. 6. Fluid cleanliness: When the medium contains impurities, a filter should be installed in front of the solenoid valve; other configurations can also be used. III. Selection of solenoid valves based on pressure rating: Principle and structural types. 1. When the solenoid valve needs to be activated for an extended period of time, and the time it remains open **exceeds the time it is closed, a normally open type is advisable. 2. If the switch is turned on and off frequently, or the time it remains on is short, or the time spent on and off is roughly equal, then a normally closed type should be chosen. 3. However, for some applications related to safety protection, such as furnace flame monitoring, gas leak detection, and fire safety interconnection systems, emergency shut-off solenoid valves should be used; permanent-powered types (where ‘permanent power’ is a relative concept) are not suitable, nor are normally open types. 4. Self-holding solenoid valves (also known as bistable valves) represent a new technology that is primarily used in applications where energy savings or operation at low voltages are required. IV. Power supply voltage selection: It is preferable to choose the commonly used AC220V; DC24V is also convenient. V. Select the control type based on the duration of operation or specific requirements: normally closed, normally open, self-holding, emergency shut-off (manual reset). 1. Nominal pressure: This parameter has the same meaning as that of other standard valves; it is determined based on the nominal pressure of the pipeline or 1.5 times the operating pressure. 2. Operating pressure difference: refers to the value obtained by subtracting the pressure in the pipeline behind the valve from the pressure in the pipeline in front of the valve, when the solenoid valve is in the closed or open state ； When there is no pressure difference, a low pressure difference, or a vacuum, a direct-acting or distributed direct-acting principle must be used ； When a certain pressure difference is achieved, various principle structural forms can be selected. VI. Selection of auxiliary functions based on environmental requirements: explosion-proof, check valve, manual, fog-proof, water spray-proof, submersible. 1. In flammable and explosive environments, explosion-proof solenoid valves of the appropriate rating must be used (our company offers EXDⅡCT5). 2. When there is backflow of the fluid in the pipeline, our company’s ZC series solenoid valves with check valve function can be selected. 3. When manual operation of the solenoid valve is required on-site, our company’s ZCA/B series solenoid valves with manual functions can be selected. 4. For outdoor installations or environments with high dust levels, waterproof and dust-proof models (with a protection rating of IP45 or higher) should be selected. For fountains or underwater pipelines, submersible solenoid valves (with a protection rating of IP68 or higher) must be used. Basis for selection 1: Choosing the solenoid valve based on pipeline parameters – diameter specification (i.e., DN) and connection type. 1. Determine the diameter (DN) according to the inner diameter of the pipelines in place or the required flow rate. 2. Regarding the interface type, flange interfaces should generally be chosen for DN＞65, while for DN≤65, either threaded or flange types can be selected according to the user’s requirements

For specific models, specifications, parameters, and pictures, you can click here to take a look: http://www.yihuan.org/diancifa.html

Solenoids are basic automation components used to control fluids; they belong to the category of actuator valves and are not limited to hydraulic and pneumatic systems. Solenoid valves are used to control the direction of hydraulic flow. Multi-channel solenoid valves have enclosed valve chambers, with holes opened at different positions within the valve; each hole leads to a different oil tube. At the center of the chamber is the valve itself, with two electromagnets on either side. When the coil of the magnet on one side is energized, the valve body is attracted to that side. By controlling the movement of the valve body, it is possible to block or allow fluid to pass through various outlet holes. The inlet hole remains open, allowing hydraulic oil to enter the different outlet tubes. The pressure of the oil then drives the pistons, which in turn move the piston rods, and these piston rods activate the mechanical device. A solenoid valve controls mechanical motion by regulating the current to the electromagnet. Ordinary solenoid valves are also used as control valves for general-purpose valves, and can be used independently on pipelines as control valves as well. Solenoid valves: water and hot water solenoid valves, liquid-gas solenoid valves, pilot-operated solenoid valves, two-port two-position direct-acting solenoid valves, gas-liquid solenoid valves, DF liquid-use solenoid valves, 2W stainless steel flanged solenoid valves, UD-C type miniature solenoid valves, RSSM type miniature solenoid valves, RSZF type diaphragm high-temperature valves, ZQDF-A universal solenoid valves, direct-acting fountain solenoid valves, ZCSB series explosion-proof solenoid valves for water dispensers, RSC series solenoid valves for water dispensers, RSO household water dispenser solenoid valves, V2A miniature solenoid valves, RSC household water discharge valves, PS steam solenoid valves, 2L steam solenoid valves, RSPS series zero-pressure difference steam valves, ZCZ series steam solenoid valves, RSPS-J stainless steel high-temperature solenoid valves, ZQDF steam solenoid valves, ZCM zero-pressure difference gas valves, DF-A type solenoid valves, ZCLF steam solenoid valves, ZCT(ZCQ) stainless steel solenoid valves, ADF ammonia-use solenoid valves, ZCF plastic king solenoid valves, 0927 diaphragm solenoid valves, 231Y three-functional solenoid valves, UQK level controllers. Dear user, please click to view the specific images and descriptions of these valves; I hope it will be useful to you. Technical support

It must be determined based on one’s actual circumstances, such as the required temperature, pressure, and other related conditions

When selecting a solenoid valve, it is necessary to determine various parameters first, such as whether it is to be used for controlling a single-acting actuator or a double-acting one, whether there are any requirements regarding switching time, and what the temperature of the instrument air is, among other things. For example, if it is to be used for controlling a single-acting actuator, with no requirements regarding switching time and under normal temperature conditions, then a standard 3/2 WAY solenoid valve with low power consumption would be an appropriate choice.

The classification and principles were explained in great detail upstairs; I’d like to recommend some manufacturers: ASCO (USA/Netherlands), HERION (Germany), FESTO (Germany), SMC (Japan): handshake