Solenoid Valves
Solenoid Valve is an electromechanically operated valve. The valve is controlled by an electric current through a solenoid: in the case of a two-port valve the flow is switched on or off; in the case of a three-port valve, the outflow is switched between the two outlet ports. Multiple solenoid valves can be placed together on a manifold.Solenoid valves are the most frequently used control elements in fluidics. Their tasks are to shut off, release, dose, distribute or mix fluids. They are found in many application areas. Solenoids offer fast and safe switching, high reliability, long service life, good medium compatibility of the materials used, low control power and compact design.Besides the plunger-type actuator which is used most frequently, pivoted-armature actuators and rocker actuators are also used.
Production
Solenoid valves are often mass produced in 3 main parts: the core tube, the nucleo and the coil.The core tube is a metal shell that is produced by deep drawing because this process requires considerably less raw material and permits complex designs that integrate solutions which reduce the amount of parts per valve .
The nucleo is typically a turned metal part, that slides within the core tube, opening or closing the valve. Its' initial position is normally maintained by a spring. The coil is a tightly bound copper wire which is wrapped around the core tube and induces the movement of the nucleo.
Types
Many variations are possible on the basic, one way, one solenoid valve described above:
- one or two solenoid valves;
- direct current or alternating current powered;
- different number of ways and positions;
Common uses
Solenoid valves are used in fluid power pneumatic and hydraulic systems, to control cylinders, fluid power motors or larger industrial valves. Automatic irrigation sprinkler systems also use solenoid valves with an automatic controller. Domestic washing machines and dishwashers use solenoid valves to control water entry into the machine. Solenoid valves are used in dentist chairsto control air and water flow. In the paintball industry, solenoid valves are usually referred to simply as solenoids.They are commonly used to control a larger valve used to control the propellant (usually compressed air or CO2). In addition to this, these valves are now been used in household water purifiers . Besides controlling the flow of air and fluids, solenoids are used in pharmacology experiments, especially for patch-clamp, which can control the application of agonist or antagonist.