What is the introduction of Solenoid Valve Types, Symbols and Configurations?

Solenoid valves are used in a wide range of applications that require liquid or gas flow control. They are used to close, open, mix, or divert media in a system, depending on the circuit function.

Solenoid Valve Types, Symbols and Configurations:
Direct acting solenoid valves operate by creating an electromagnetic field in the coil that attracts the plunger up to open or down to close the orifice when the current is turned on. This is known as a “direct” or “non-inductive” operating principle, and it’s most common for applications with low pressure or small flows.

Normally closed indirect-operated valves are typically used for high flow rates and a sucient pressure dierential (a 0.5 bar minimum is needed). Pilot-operated solenoids perform like direct operated valves, but they don’t need power or a pressure difference to operate.

The basic working principle is a movable plunger that’s built of ferromagnetic materials, such as NBR, EPDM, FKM or PTFE. It interacts with a magnetic field generated in the coil when an electrical current is passed through it to open or close the valve.

Three-way or bi-stable solenoid valves have a total of two inlets and one outlet for connection. They switch between two circuits or mix them together based on which port is activated at a given moment.
Many designs also have a spring mechanism that presses against the plunger to keep it in a certain position with no power applied. Some bi-stable valves have a latching solenoid that uses permanent magnets instead of a spring to stay in the same position when power is removed.