Detailed Introduction 1. Product Overview A solenoid valve is an automated actuator that relies on the magnetic force generated by an electromagnetic coil to drive the valve core to move, thereby controlling the on-off, switching, or regulating of fluids such as gas, liquid, and oil. It is one of the most widely used terminal actuating components in industrial automation control systems and is known as the "switching hand of automation equipment".
When the coil is energized, the magnetic field attracts the moving iron core, driving the valve core to displace and changing the connectivity state of the internal flow passage of the valve body. After power is cut off, the reset spring pushes the valve core back to its initial position, restoring the original passage. The entire process involves no motor or gear transmission, featuring a compact structure and rapid response.
Our solenoid valve products cover a full range of passage types, including 2-position 2-way, 2-position 3-way, 2-position 5-way, and 3-position 5-way, with diameters ranging from DN1 to DN50. They are suitable for air, water, oil, steam, gas, and various weakly corrosive media, and are widely used in fluid control systems in the fields of industrial automation, automotive electronics, medical equipment, HVAC and environmental protection, new energy, and more.
II. Operating Principle The core action logic of the solenoid valve can be summarized into four steps:
Coil energization - Current passes through the electromagnetic coil, establishing a magnetic field around the iron core; magnetic field attraction - The magnetic field exerts an electromagnetic attraction force on the moving iron core (armature), overcoming the pre-tension force of the return spring; valve core displacement - The moving iron core drives the valve core to move, causing the sealing surface of the valve port to separate or engage, resulting in a switch in the flow passage state; power-off reset - The coil is de-energized, the magnetic field disappears, and the return spring pushes the valve core back to its initial position.
The entire action cycle typically ranges from 5 ms to 50 ms, and the mechanical lifespan can reach 1 million to 10 million cycles (depending on the structure and operating conditions). Since the action relies on the balance between electromagnetic force and spring force, the solenoid valve exhibits almost no delay in response to control signals, making it highly suitable for high-frequency, high-tempo automated production lines.
III. Core structural components
Function Description
electromagnetic coil
The power source of solenoid valves is the magnetic field generated by electricity. According to voltage, they can be divided into DC12V/24V, AC110V/220V, etc
Fixed iron core
Form a magnetic circuit in conjunction with the coil to provide a reference plane for attractive force
Moving iron core (armature)
Displacement is generated by magnetic attraction, directly driving the valve core
Return spring
After power failure, push the valve core back to its initial position, which determines the reliability of resetting and the minimum operating pressure
Valve core and sealing surface
It works in conjunction with the valve seat to achieve sealing, and its material directly affects its lifespan and compatibility with the medium
valve body
It carries the internal flow passage and inlet/outlet, and determines the diameter, pressure resistance, and installation interface
Manual emergency device
Some models are equipped with manual buttons, facilitating debugging and emergency power-off operations
IV. Main Technical Parameters
Explanation
Optional range
Operating voltage
Rated voltage of coil
DC 12V / 24V, AC 110V / 220V
Allowable voltage fluctuation
Voltage range ensuring reliable operation
±10%
Nominal diameter DN
The inner diameter of the flow channel determines the flow capacity
DN1 ~ DN50
work pressure
Pressure range for normal operation
0 ~ 1.0 MPa (up to 2.5 MPa for high-pressure models)
Medium used
Compatible fluid types
Air, water, oil, steam, gas, refrigerant
medium temperature
Permissible fluid temperature range
-10℃ ~ +180℃ (depending on the sealing material)
Ambient temperature
Permissible operating ambient temperature
-20℃ ~ +60℃
Valve position and passage
Number of working positions and number of interfaces
Two-position two-way / Two-position three-way / Two-position five-way / Three-position five-way
mode of action
Electromagnetic drive form
Direct-acting type / Pilot-operated type / Step-by-step direct-acting type
Sealing material
Seal components in contact with the medium
NBR / EPDM / FKM (Fluororubber) / PTFE
Valve body material
Main body shell material
Brass / Stainless Steel 304, 316 / Engineering Plastics
Protection level
Dust and water resistance
IP54 / IP65 / IP67
Explosion-proof level
Applicability in flammable and explosive environments
Intrinsically safe type Ex ia, flameproof type Ex d IIB T4
electrical interface
wiring method
Lead-in type / DIN plug type / Terminal type
Installation Method
Valve body installation form
Pipe connection type / Plate type / Flange type
5. Action Mode Comparison 5.1 Direct-acting solenoid force directly drives the valve core action without relying on medium pressure. It can operate normally with zero pressure difference and is suitable for vacuum, low pressure, and low flow applications. The disadvantage is that the diameter is limited by the solenoid force (generally ≤ DN10), and the coil power consumption is relatively high, making it unsuitable for large flow control.
5.2 The pilot-operated solenoid force only drives the pilot small valve, while the main valve core relies on the pressure difference of the medium itself to open. It has a large diameter, low power consumption, and minimal heat generation, making it suitable for high-flow applications such as water treatment and central air conditioning. The disadvantage is that it requires a minimum working pressure difference (generally ≥ 0.05 MPa) and may fail under zero or low pressure conditions.
5.3 Step-by-step direct-acting type combines the advantages of both direct-acting and pilot-operated types: it operates in a direct-acting manner at low pressures and automatically switches to pilot-operated driving when pressures rise. It can be started with zero pressure difference, features low power consumption and a large flow path under high pressures, making it particularly suitable for applications with significant pressure fluctuations, such as gas, water supply, and irrigation.
Comparison item
Direct-acting
Pilot-operated
Step-by-step direct-acting type
Minimum working pressure difference
0
≥ 0.05 MPa
0
Maximum drift diameter
≤ DN10
DN15 ~ DN50
DN15 ~ DN50
Coil power consumption
higher
low
moderate
Applicable flow rate
low flow
High traffic
Medium to high flow
Typical Applications
Medical devices and instruments
Central air conditioning, water treatment
Gas, irrigation, water supply