Overview of 2-way Solenoid Valve

A 2-way solenoid valve is an electromechanically operated fluid control component that features one inlet port and one outlet port, designed to start, stop, or regulate the flow of media (including fluids, air, gases, and other process liquids/gases) in automated systems. It is controlled by an electric current passing through the internal solenoid coil, which generates magnetic force to actuate the valve spool or poppet and switch the flow path.

Basic Classification

Based on the initial state when de-energized, it is mainly divided into two types:

1. Normally Closed (NC) 2-way Solenoid Valve: Flow from the inlet to the outlet is completely blocked when the power is off, and the valve opens to allow flow only after it is energized. It is the most common type for general process control scenarios.
2. Normally Open (NO) 2-way Solenoid Valve: The valve remains open and allows flow when the power is off, and closes to block flow after energization, which is suitable for emergency cut-off or special energy-saving applications.

Working Principle

When the solenoid coil is energized, the generated electromagnetic force lifts or moves the internal closing member (poppet/spool), opening the orifice to allow media to flow through the valve from the inlet to the outlet. When the power is cut off, the electromagnetic force disappears, and the spring reset mechanism pushes the closing member back to the original position, closing the orifice and blocking the flow. For pilot-operated 2-way solenoid valves, a minimum differential pressure across the valve ports is required for operation, and it can achieve higher flow capacity with smaller overall dimensions.

A Five Way Solenoid Valve is an electromechanical fluid control component with five ports, primarily used to control the flow path of gases, liquids, or steam in automated systems. It is actuated by an electromagnetic coil, which drives the internal spool or piston to switch the flow path among the five ports, enabling precise control of fluid direction and pressure.

Core Types and Characteristics
1. 5/2 Way Solenoid Valve
Basic Structure: It has 2 working positions and 5 ports, including 1 inlet (P), 2 working outlets (A, B), and 2 exhaust ports (R, S).
Working Principle:
When de-energized, the spring resets the spool to the default position, connecting the inlet to one working port and the other working port to the exhaust port.
When energized, the electromagnetic force moves the spool, switching the inlet to the other working port and redirecting the first working port to the exhaust port.
Common Applications: Widely used to control double-acting cylinders in automated production lines, pneumatic systems, and packaging equipment, enabling the cylinder to extend and retract.
2. 5/3 Way Solenoid Valve
Basic Structure: It has 3 working positions and 5 ports, including 1 inlet (P), 2 working outlets (A, B), and 2 exhaust ports (R, S). It is usually equipped with dual solenoid coils.
Working Principle:
When both coils are de-energized, the spool is in the middle position. Depending on the design, it can be:
Closed-center type: Blocks all ports, allowing the cylinder to be positioned at any intermediate point, suitable for temporary emergency stop scenarios.
Pressure-center type: Keeps the cylinder chambers under backpressure, preventing impact when the system restarts.
Exhaust-center type: Connects both working ports to the exhaust port, allowing the piston rod to be manually moved, convenient for maintenance.

The reason for measuring the AC component is that compared to the DC component the electronics are more sensitive. The AC signal is substantially less affected by influences such as amplifier noise and process parameters, which includes the build-up of process dust on the sensing rod. The EMP6 remote sensing head totally filters out any 50Hz or 60Hz frequencies related to mains supply. The amplified signal is then sent via data cable to control unit for further processing and display.

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