|Please specify solenoid
type, duty cycle, stroke for required force and minimum
force at stroke, we will recommend a solenoid for your
Solenoid valves are used for controlling the flow of liquid or gas. These are
controlled units that operate electromechanically. The basic working principle
of a solenoid is that when an electric current is passed, it opens or closes
allowing or blocking the passage of liquid or gas. A solenoid is the electric
coil, in the center of which a plunger is present. The plunger is a
ferromagnetic core and is moveable. It sits at the mouth of a small opening
while the valve is at rest. A strong magnetic field is created in the coil when
an electric current is introduced. This exerts a force on the plunger and it
moves upward leaving the orifice open.
Solenoid valves are only used for clean liquids or gases. Apart from opening
or closing of outlets, they can also be used to mix or distribute media from two
or more outlets.
Solenoid valves are fast operating units that are commonly used in heating
systems, irrigation, car washes, vacuum, compressed air, etc.
Circuit Functions of Solenoid Valves
Solenoid valves are configured as 2-way and 3-way valves and their operation
is specified by their circuit function.
· 2-way Solenoid Valve:
This type of solenoid valve has two ports. One is the inlet and the other is
the outlet. To ensure the smooth functioning of the valve the flow of media
should be unidirectional. Usually, an arrow is marked to indicate the direction
of flow. These 2-way solenoid valves are used to open and close the vent.
· 3-way Solenoid Valve:
As the name suggests, this type of solenoid valve has 3 connection ports. It
has two states of placements by switching between two different circuits. A
3-way solenoid valve is used to close, open, mix, or distribute media.
Types of Solenoid Valves
· Normally closed
A solenoid valve that is normally closed type blocks the flow of media
through it when it is de-energized. And when an electric current passes through
it, an electromagnetic field is generated which pushes the plunger upward due to
which the seal of the orifice opens and flow of media continues.
· Normally open Solenoid Valve
A solenoid valve in a normally open configuration is just the opposite. In
its de-energized state, the valve is open and the media flow is allowed to pass
through. And when current is passed through the solenoid, the electromagnetic
field that is generated forces the plunger down as a result of which the vent is
closed and flow of media is discontinued.
· Bi-stable Solenoid Valve
A bi-stable solenoid valve can be switched on and off using a transient power
supply. Once switched on or off, it stays in that position even with no power;
this is why they are also called latching solenoid valves.
Bi-stable solenoid valves do not have normally closed or normally open
configurations. Rather they stay in the current position when no power is
provided. This latching function is achieved using permanent magnets instead of
Solenoid valves are widely used in a large number of industrial and domestic
applications. Irrigation systems have solenoid valves installed for automatic
water supply and control. Similarly, air conditioners use solenoid valves to
control air pressure. The refrigeration systems have solenoid valves
incorporated to reverse the flow of refrigerants upon requirement. Water flow in
dish-washers, washing machines, car washing facilities, and water tanks is also
controlled through solenoid valves. They are also used in automatic locking
systems for door locks.
Solenoid valves use
Pulse Width Modulated (PWM) modules for varying load. The output voltage is
varied according to the input voltage. Other solenoid valve accessories like a
controller card and a mount bracket are also available.