Pneumatic solenoid valves are the unsung heroes of industrial automation of today’s world. There are many industries that require plenty of pneumatic actuators including machines, tools and robots. These valves help to maintain the operational efficiency of air-powered automated systems, by controlling airflow rate, pressure, and direction.
However, there are various types of valves designed for specific purposes. As long as the valve is applied, the application can be enhanced with different types of 2/2 or even 5/2 valves which can improve performance and decrease operating costs. Let’s explore what pneumatic solenoid valves are, their types, working, and more. So, keep reading!
1) What are pneumatic solenoid valves?
“Pneumatic solenoid valves are used in pneumatic systems to switch on and off the airflow or compress gas systems.”
These valves tend to work like switches where applying current from the electric source or solenoid coil opens up the valves. The electric current energizing the solenoid generates a magnetic field that moves the internal plunger up and down Thus, allowing or stopping the flow of air through the valve.
Easy to use and reliable, solenoid valves pneumatic are found in many industries, including manufacturing, automotive, and even healthcare. They are essential for controlling pneumatic devices, Tools, and machines during controlled movements of air pressure and air direction. Moreover, these are the elements of robotic arms in production lines and precision medical devices.
Figure no 2 Air solenoid valve
These valves can be 2-way, 3-way, or 5-way types ( detail in coming sections) among others in relation to the application. Each configuration determines how the valve opens and closes to direct the airflow for the completion of its respective functions. Their small size, quick actuating time, and high stability make these valves suitable for many applications.
2) How pneumatic solenoid valve works?
The working principle of pneumatics solenoid valve is something which requires a big consideration to understand. Let’s breakdown the whole process into simple steps;
Step 1) In the absence of power which is when the solenoid valve plate is not charged (energized), the plunger is held at its natural position. Depending on the valve design, this could either mean opening the flow path or blocking it.
Step 2) As soon as the electrical power supply to the solenoid is completed, the coil generates magnetic forces.
Figure no 3 Magnetic field generation
Step 3) This movement can be in the form of either shifting the plunger upwards or downwards depending on the configuration of the valve.
Step 4) The air enters the valve from the ports, and it will be delivered via specially designed vessels for pneumatic actuators air cylinders, or other system components.
Step 5) Cut off the power supply nonetheless, its application to a coil is no longer there, so there is no magnetic field. The coil is in an idle state; air can be cut off from the cavity. Such simple switch features allow pneumatic solenoid valves to have very high accuracy and speed.
3) What are the types of pneumatic solenoid valves
Air solenoid valves are classified into different types based on their port configurations and various mechanisms enabling different functionalities in a pneumatic system. Below is an in-depth exploration:
i) 2/2 solenoid valves ( Two-way, Two-position)
2/2 solenoid valves employ two ports with an inlet and an outlet port with only two operating positions, on or off. These valves can be termed as directional control valves for they enable and disable air flow. They are useful for simple functions such as the on-off control of tools or processes in air supply.
ii) 3/2 solenoid valves (Three-way, two-position)
These valves have three ports and function as alternators with one of the ports supplying air. While, the other is an exhaust port. One port is connected to the supply of air while the other one is for the actuator and the third is for the exhaust air port. They are best for single-acting cylinders or actuators that have a single direction of movement. Simple tasks like clamping or releasing are easily performed by these devices.
iii) 4/2 Solenoid Valves
4/2 solenoid valves feature a total of four connections: 2 that get attached to the actuator, one that pulls in the air supply, and one that pushes it out. These valves are responsible for supplying compressed air to one of the two actuator links, and eliminating the other link. Commonly these valves are used together with double-acting cylinders for bi-directional motion in industries such as robotics and conveyor systems.
iv) 5/2 Solenoid Valves
These valves are almost similar to 4/2 valves but they include an extra exhaust port. The extra port helps to enhance the airflow distribution for improved efficiency and performance. They are quite useful in systems that require faster or more precise control of the air exhaust. These are especially for double-acting actuators with complex operations.
v) Diaphragm type Direct Type Solenoid Valve
Direct-acting valves do not depend on the pressure in the system. The actuation of the valve through a solenoid causes it to either close or open directly which is the desirable case. This type of design suits most low-pressure systems. Or, applications that need a rather quick response. Such valves are normally small in size and are reliable for use in small pneumatic systems.
vi) Pilot-operated Solenoid Valves
Pilot Valves also called pilot-operated valves utilize the pneumatic force of the system to lighten the work done by the solenoid hence increasing its efficiency. They are quite effective in applications that are high in volume or pressure. Because they are able to work together with a high volume of air usage and still be effective which is efficient.
vii) Proportional Solenoid Valves
Proportional valves enable control of a certain parameter by varying the position of the valve to a certain degree. In contrast to on/off valves, these valves switch but the amount of air or pressure can be varied. Such features enable usage in applications where settings require a fine touch, for instance, medical or delicate manufacturing types of machinery.
Here an important this to discuss with you The FoyeAuto provides a series of pneumatic solenoids valves, and mechanical screws with:
- 4V100 Series Solenoid valves: Small size adequate for lightweight type applications. Operates in internal pilot mode. Two-position or three-position applications can be used. Appealing for small pneumatic systems.
- 4V200 Series solenoid valves: There are five-port two-position and five-port three-position features available. Is effective at a pressure of approximately 0.15–0.8 Megapascal and can tolerate pressures up to 1.2 MPa. This type of construct is made of aluminum alloy and can withstand a temperature range of -20 to 70 degrees Celsius. This device has voltage options of AC and DC.
- 4V300 Series solenoid valves: The replacement of flat springs increases the fatigue life with a sliding column structure for better sealing and response. This device can perform the functions of a three-position valve with memory functionality. This device also has a wide voltage range and lubrication-free operation. This device is intended for the close control of flow rates, typically for use in industrial applications.
- 4V400 Series solenoid valves: This device has larger capacity valves suitable for a more demanding application. This device is capable of functioning at a wide pressure range and temperature extremes. Due to features like on-off switches, some manual operation is possible hence maintenance is simple.
These devices are however found in the manufacturing, automation, and packaging industries due to their robust designs and interchangeable parts. A more comprehensive interpretation of the characteristics and help with the selection can be found further here in the catalog FoyeAuto.
4) How to choose the suitable pneumatic solenoid valve?
There are quite a number of factors when selecting a pneumatic solenoid valve that makes the work system efficient. Some of the key steps include:
? Consider the Application: What type of valve is needed? Is it to be an actuated air control valve operating a single-acting cylinder, a double-acting cylinder, or a valve capable of controlling pressure or directing flow?
? Port Configuration: Indicate the appropriate port configuration, such as 2/2, 3/2, 4/2, or 5/2. This will depend on the number of air supply, actuator, and exhaust ports the system will require.
? Operating Pressure and Flow Rate: Check if the valve is capable of withstanding the operating pressure and the flow rate for the system.
? Actuation Type: Choose the valve type between direct-acting or pilot-operated valves based on the pressure level and response time requirements in your system.
? Material Compatibility: Pick the materials suitable to the working conditions and the working medium of air, gases, or fluids. In extreme conditions, corrosion-resistant materials should be employed.
5) Conclusion
It is a fact that in today’s industrial automation systems, there is a wide range of pneumatic solenoid valves that enable precise airflow and pressure control. And, these include all possible types of 2/2, 3/2, 4/2, and 5/2 valves, specialty series from Foye, and various types.
There is no shortage as well in the assortment available for such systems. All these types of valves offer businesses the opportunity to choose the best valve that would improve efficiency, reliability, and performance in their system regarding the application.