When it comes to engineering, there are a lot of different tools and parts that are needed to complete any project. Engineering uses both science and technology in order to design and build things such as machines and structures. Thus, the tools and parts that are used in engineering often have very specific purposes and functions. Many parts are designed to measure certain things (such as the flow of a fluid), or to turn things on, off, or open and close. Solenoid valves are engineering parts designed with a specific purpose, which is often to control fluids. To understand more about these valves, it also helps to understand what a solenoid is, types of solenoids used in various applications, what the function of the valve is, and applications in which solenoid valves are used.


What is a Solenoid?


In engineering, a solenoid is a kind of transducer. Transducers are items that are able to convert certain types of energy into other types of energy. In the case of a solenoid, the transducer changes energy into motion. A solenoid is a helical coil, or a coil that is wound into a helix shape. For engineering, usually the solenoid is electromechanical, which means the coil is positioned around an armature made of steel or iron. The inductiveness of the coil can be changed by simply moving the steel or iron armature in and out of the coil. Solenoids seem to function best over short distances, although a controller circuit is a great way to get direct control over them for longer distances. Using a controller circuit also allows for immediate reaction of the solenoid.


In the case of a solenoid valve, energy is converted as it flows through the solenoid, which in turn either closes or opens the valve. When the valves are not in an activated state, they may be held open or closed by a spring to help control fluid flow.


Types of Solenoids


There are a lot of different types of solenoids, such as:


  • Electromechanical
  • Rotary
  • Automobile starter
  • Hydraulic solenoid valve
  • Pneumatic solenoid valve


Certain solenoids have specific functions. A rotary solenoid is not used the same way as a hydraulic solenoid valve, for example.


Function of a Solenoid Valve


A solenoid valve is basically used to control the flow of things like air or water. There are many reasons why a valve might be placed in a certain location. The valve has the ability to turn the flow of fluids on or off at specified intervals. There can be more than one solenoid valve in a given system. For example, there could be one or two one-way solenoid valves in a system, or valves operated either by direct current or alternating current. It depends on what the valve is controlling. Pneumatic solenoid valves move air to a device operated by pressurized gas, most often a motor. Hydraulic solenoid valves function similarly to pneumatic solenoid valves. Instead of pressurized gas, hydraulic solenoid valves control and route hydraulic fluid like oil to motors.




You can find different types of solenoid valves in all kinds of systems. For engineering purposes, electromechanical solenoids are used in paintball, fuel injectors, and even certain types of printers. You even have a solenoid connected to the starter of your car—which is what makes the clicking noise when your battery is dead and the car won’t start. Solenoid valves have a lot of other common uses, such as controlling the flow of water in an irrigation sprinkler system, and controlling water flow and level in washing machines and dishwashers. If you have a machine that releases fluid at specified intervals for specific purposes, chances are quite high that the machine has some sort of solenoid valve in it.


Solenoid valves are a very important component for many different aspects of engineering. They can serve a lot of different purposes depending on what you are building. Many of the machines that you commonly use would not be able to function as well as they do without a solenoid valve in place. Gas-powered air rifles and paintball guns, your washing machine filling up, your dishwasher washing dishes, and even your car turning on properly are all possible thanks to solenoid valves. If you are working on a project and are looking for a way to control the flow or release of gas or fluid by means of an electrically-activated switch, then you might need to look into a solenoid valve.