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Wednesday, August 22, 2012

Solenoid valve control

Solenoid valves are normally used in engineering projects where water or liquid or gas flow controls are needed. I would like to describe some of its basics, features and applications in this article.
A solenoid valve is an electromechanical valve to control the flow of liquid or gas. The valve can be controlled by passing electrical current through a solenoid. There are two practical cases for control. One control is a two-port valve where the flow is switched on or off.  In the second case, a three-port valve is used in which the outflow has been switched between the two outlet ports. Multiple solenoid valves can also be used together on a manifold. Solenoid valves are often used as control elements in fluids/gas. Their main works are to shut/close off, release, dose, distribute or mix fluids. 


Solenoids features are
* very fast and safe switching,
* high reliability,
* long service life,
* good medium compatibility of the materials used,
* low control power and compact design.
Most of the applications use the plunger-type actuator and the other types are pivoted-armature actuators and rocker actuators.
 
Description about Solenoid valve: 
A solenoid valve consists of  two parts. They are solenoid and the valve. The solenoid part converts electrical energy into mechanical energy which is used for opening or closing the valves mechanically. Solenoid valves are normally metal seals or rubber seals, and have electrical interfaces to allow for controlling. A spring is  used to hold the valve opened or closed while the valve is not activated. In solenoid valves, particularly few cases, the solenoid acts directly over the main valve. Others use a small, complete solenoid valve, known as a pilot, to actuate a larger valve. While the second type is actually a solenoid valve combined with a pneumatically actuated valve, they are sold and packaged as a single unit referred to as a solenoid valve. Piloted valves consumes very less power for controlling, however, they are very slower. Piloted solenoids usually need full power at all times to open and stay open, where a direct acting solenoid may only need full power for a short period of time to open it, and only low power to hold it. 
Applications: 
Solenoid valves are used in 
* fluid power pneumatic and hydraulic systems, to control cylinders, fluid power motors or larger industrial valves. 
* solenoid valves with an automatic controller are used in automatic irrigation sprinkler systems. 
* solenoid valves are used to control water entry to the machine in domestic washing machines and dishwashers. 
* 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 the industry, "solenoid" may also refer to an electromechanical solenoid commonly used to actuate a sear.