Solenoid valves are automated actuators that control the on/off or flow direction of fluids through electromagnetic force. Their core features and applications are as follows:
1. Basic definition
Functional positioning
The magnetic field generated by the electromagnetic coil drives the valve core to achieve precise control of liquids, gases and other fluids (opening and closing, flow direction switching or flow regulation).
Technical positioning
It is a basic actuator for industrial automation, integrating electromagnetic drive, fluid mechanics and material science to support the efficient operation of modern intelligent control systems.
2. Core Structure
| Components | Functional Description | Features |
|---|---|---|
| Solenoid coil | After power is turned on, a magnetic field is generated to drive the valve core to move | Load voltage range: 12V-220V (commonly used 24V DC) |
| Valve core | The magnetic field produces displacement, changing the state of the fluid channel | Stainless steel/ceramic material, resistant to high temperature and high pressure |
| Valve body | Carrying fluid channels and providing sealing interfaces | 316L stainless steel/PTFE lining |
| Return spring | Push the valve core to reset after power failure | Fatigue-resistant design (≥ 1 million cycles) |
3. Working Principle
Power-on state
When the coil is powered on, an electromagnetic field is generated, and the magnetic force attracts the valve core to move and open the main flow channel.
The flow control accuracy can reach ±2% (intelligent type with PID adjustment).
Power-off state
The spring pushes the valve core to reset and cut off the fluid passage, with a response time of up to 15ms.
The failure protection design can preset the open/closed state (such as the fire protection system forced to remain open).
4. Technical Classification
| Classification Dimension | Type Examples | Application Scenario |
|---|---|---|
| Drive mode | Direct acting (small flow), pilot type (high pressure difference) | Pneumatic control circuit, hydraulic system |
| Fluid Medium | Gas valve (explosion-proof design), liquid valve (anti-corrosion coating), vacuum valve (hysteresis-free seal) | Chemical pipelines, vacuum coating equipment |
| Functional Mode | Normally open, normally closed, self-holding (pulse trigger) | Smart home water control, industrial production line |
| Smart Extensions | Wireless control type (Wi-Fi/LoRa/NB-IoT) | Remote irrigation system, unmanned chemical factory |
5. Typical applications
Industrial automation
Hydraulic oil circuit control of injection molding machines (pressure range 0.02-31.5MPa)
Clean pipeline sterile fluid switching in pharmaceutical factories
Civil fields
Smart toilet water circuit control (24V safe voltage design)
Central air conditioning refrigerant distribution system
Special scenarios
Emergency cut-off of spacecraft fuel supply (20g vibration resistance)
Radioactive medium isolation of nuclear power plants (radiation shielding design)
6. Performance parameters
Temperature range: -50℃ (low temperature fluororubber seal) to 350℃ (high temperature alloy valve body)
Leakage level: ANSI/FCI 70-2 Class VI (bubble-level seal)
Life index: Mechanical life ≥ 10 million times (aviation-grade solenoid valve)
The device has become the core control node of modern Industry 4.0 and Internet of Things systems through the precise coupling of electromagnetic drive and fluid control.