What is a 2-position 2-way solenoid valve?

A 2/2-way solenoid valve is a fundamental component in fluid control, using electromagnetic force to quickly open and close a flow path. The "2-position" in its name refers to the valve core's two operating positions (on/off), and the "2-way" designates its two connections (inlet and outlet).

1. Function of a 2/2-way solenoid valve

Basic Function

Powered on: The valve core actuates, allowing fluid to flow from the inlet (P) to the outlet (A).

Powered off: The valve core returns to its original position, completely shutting off the flow path (normally closed) or maintaining flow (normally open).

Control Logic

It only has an on/off function and cannot adjust flow (unlike a proportional valve).

Response time is typically ≤50ms, making it suitable for high-frequency, rapid switching.

2. Key Selection Parameters

Fluid Compatibility

Water/Gas/Oil: Matching sealing materials are required (NBR is oil-resistant, EPDM is acid- and alkali-resistant).

Corrosive Media: Select a polytetrafluoroethylene (PTFE) valve seat.

Pressure Range

Minimum Starting Pressure: Direct-acting type ≥ 0 bar, pilot-operated type > 0.3 bar.

Differential Pressure Limitation: Calculate the CV value (flow capacity) for high flow rates.

Electrical Characteristics

Power Consumption: Energy-saving coils are only 2-5W. Continuous power supply requires a design to prevent overheating.

Protection Rating: IP67 for outdoor use; Ex dⅡCT6 for explosion-proof applications.

3. Installation and Maintenance Key Points

Installation Specifications

The direction of the arrow must align with the fluid flow direction (reverse installation may cause leakage).

Horizontal installation is preferred over vertical installation to prevent valve core sticking.

Troubleshooting

Coil burnout: Check voltage fluctuation (within ±10%).

Valve core stuck: Clean the filter (impurity particle size < 10% of the valve orifice diameter). Leakage: Replace the seal (nitrile rubber has a lifespan of approximately 3-5 years).

Lifespan test

On-off cycle test (e.g., check the seal after 500,000 cycles).