Questions regarding the distinction between 2/3-way and 2/5-way solenoid valves
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Regarding the distinction between 2/3-way and 2/5-way solenoid valves: To tell the difference between them, one can look at their connections and operating mechanisms – a solenoid valve with one coil is a 2/3-way valve, while one with two coils is a 2/5-way valve. ---- Connections In terms of the air (or liquid) circuit, a 2/3-way solenoid valve has one inlet port for connecting to the air supply, one outlet port to supply air to the target device, and one exhaust port; usually a silencer is installed at this port, though it can be omitted if noise is not a concern @_@. The two five-way solenoid valves have 1 air intake port (connected to the air supply source), 1 air outlet port for forward operation and 1 air outlet port for reverse operation (providing air supply for forward and reverse operations to the target device respectively), 1 exhaust port for forward operation and 1 exhaust port for reverse operation (equipped with a silencer). For small automatic control devices, industrial rubber air hoses with a diameter of 8~12 mm are generally used for the air supply lines. Solenoid valves are generally chosen from Japanese brands such as SMC (higher quality, but it’s a Japanese product), Taiwanese brand ADTECH (affordable with good quality), or other domestic brands. From an electrical perspective, 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. Operation principle of normally open 2/3-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 also known 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”. Based on these characteristics of the two-position five-way dual-control solenoid valves, when designing the electromechanical control circuit or writing PLC programs, it is sufficient to allow the solenoid coils to operate for 1–2 seconds; this helps to prevent the solenoid coils from being damaged.
1. Two-position three-way solenoid valve: Two-position refers to the fact that the valve core of the solenoid valve has two different operating positions (open, closed). A three-way valve refers to a solenoid valve whose valve body has three port openings ； The two-way three-position solenoid valve controls fluid with one inlet and two outlets (the two outlets are one normally open and one normally closed) ； Two-way three-port solenoid valves are generally single-electric-control (i.e., single coil). Under normal circumstances, one channel is connected to the air source, while the other two channels are connected—one to the air inlet of the actuator and the other to its air outlet. The specific working principle can be found in the schematic diagram of a single-acting pneumatic actuator. 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 2/3-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, which is also a form of \"momentary operation\". 2. Two-position five-way solenoid valve: The “two-position” feature means it can be controlled in two states: on or off. The “five-way” aspect indicates that there are five channels for air flow; 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 its working principle, refer to the working principle of double-acting pneumatic actuators. Wutong solenoid valves come in single and dual-electronic control versions (i.e., single-coil and double-coil). 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”. Two five-way solenoid valves are typically used in conjunction with double-acting pneumatic actuators. The coil voltage levels are generally DC24V, AC220V, etc. 3. Direct-acting and pilot-operated solenoid valves: There are types such as direct-acting and pilot-operated solenoid valves: a. 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, or zero pressure, but the diameter generally does not exceed 25 mm. b. Pilot-operated solenoid valve: Principle: When powered, 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, thereby 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 higher at the bottom and lower at the top around the valve closing element. The fluid pressure then pushes the closing element downward, thereby closing the valve. Features: High upper limit for fluid pressure range; can be installed in any position (customization required), but must meet the fluid pressure difference requirements
I’ve learned something, during the study... Thank you!
The main difference lies in the two-position valves used for dual-cylinder systems; after all, such systems have both an inlet and an outlet. Either a two-position five-way solenoid valve is used, or a combination of a two-position three-way solenoid valve and a two-position five-way control valve, or yet another combination of a two-position three-way solenoid valve and 2 two-position three-way control valves. Solenoid valves CV are generally quite small; if a fast switching time is required, a pneumatically controlled valve is needed. Molecular sieves used in air separation processes tend to be paired with two-position five-way solenoid valves, and ASCO offers a model claimed to be capable of 100,000 actuations. Hehe, it’s just my personal understanding; please don’t laugh at any shortcomings.
It would be easier to understand if the expert could provide an animated schematic diagram along with textual explanations; that way it can be grasped better
Sometimes, accidentally, you end up with fake products whose diagrams are incorrect; it’s really frustrating