The so-called "electric solenoid valve" is actually an electric valve, and the term "pneumatic solenoid valve" may be wrong. Generally, it refers to a pneumatic valve. The differences in their principles are as follows:

Working principle of electric valve

Electric valves are devices that open or close valves through the drive of an electric motor. Their working principle is to convert electrical energy into mechanical energy, thereby driving the movement of the valve. Generally, the opening and closing of the valve body are controlled through mechanical structures such as motors and reducers. They typically use DC or AC power sources for driving and can adjust the degree of opening and closing according to needs.

Working principle of pneumatic valve

Pneumatic valves are devices that control the opening or closing of valves through air pressure. The working principle is that the valve's action is driven by the air pressure provided by the air source. For example, pneumatic piston actuators use compressed air as the power source, and the movement of the piston drives the crank arm to rotate 90 degrees, achieving automatic valve operation; pneumatic control valves consist of an actuator and a control mechanism. The actuator generates corresponding thrust based on the pressure of the control signal, which then drives the control mechanism to operate. The valve body directly contacts the regulated medium, adjusting the flow rate of the fluid.

To sum up, the electric valve relies on the mechanical power generated by the motor to drive the valve, while the pneumatic valve relies on the air pressure provided by the air source to drive the valve action.