Selecting the correct valve in today’s modern industry can greatly affect the efficiency and performance of a system. But with so many choices, how do you know which works best with your system, solenoid or pneumatic valves? But don’t worry, you’re in the right place. In this blog, we’ll explain everything about solenoid valves and pneumatic valves so that you can make the best choice for your system. So, let’s start now!
1) What is a Solenoid Valve?
“A solenoid valve is a type of valve that uses electricity to control the flow of liquids or gases through a system.”
A solenoid valve is opened and closed by an electric current which energises the solenoid coil, forming a magnetic field that moves an associated plunger. Often, they are used in the machinery of industrial automation, water treatment, HVAC systems, and irrigation.
These solenoid valves offer compact design and reliable operation, including remote and automatic control. Moreover, solenoid valves are custom-built in extensions and varieties; they are best optimised for the specific use of fluids. Actually, the coil of wire contains a metal part that either opens or closes a valve, depending on the direction in which the current is passed.
Components of a solenoid valve:
We will now analyse the vital elements that enable the optimal functioning of a solenoid valve.
- Electromagnetic Coil: This is the central part of the valve. When an electric current passes through the coil, it allows it to create a magnetic field essential for the solenoid valve to perform its work properly.
- Plunger (Armature): A metal rod that can be easily magnetized and readily springs back to its original position, allowing the valve to open and close as needed.
- Spring: Serves to return the electromagnetic component ( metal rod) when power is switched off.
- Valve Body: The external casing that contains the valve. It consists of strong brass, plastic, or stainless steel.
- Seal or Diaphragm: The seal keeps the valve from leaking when it’s closed, ensuring no gas or liquid escapes.
- Inlet and Outlet Ports: These are the parts that allow a flow of gas or liquid in and out of the valve.
➔ How it operates:
An electrical solenoid valve functions using a coil of wire placed around a cylinder. When an electric current flows through a wire, it creates a magnetic field that allows the spring to move the plunger inside the cylinder that controls the flow of a liquid or gas.
Let us look at why solenoid valves are incredibly helpful:
- Precise Operation: Solenoid valves offer a great range of precision. They are ideal for automation and timed operations because they turn on and off instantaneously when energised or deactivated.
- Compact Design: The main plus point of these valves is their compact size and light weight compared to other valves.
- Low Maintenance: It needs less maintenance compared to other valves because the selenoid valve has fewer moving parts.
Types of solenoid valve
Now, let’s examine the two basic types of solenoid valves :
i) Direct-Acting Solenoid Valve:
This type opens and closes directly with an electric signal, it is suitable for low-pressure systems. Direct-acting solenoid valves are simple and efficient, and work great for small applications.
ii) Pilot-Operated Solenoid Valve:
Pilot-Operated solenoid valves are the best choice for high-pressure or large-flow systems. When an electric current passes through the coil, it opens up a small passage ( pilot). Due to the opening of the path, the pressure changes inside the valve.
This change in pressure results in the movement of the valve. These valves give more control and are primarily used in bigger systems.
Solenoid valves focus on precision, control, and ease of use, which is why they are used so often in different industries. Are you ready to find out what differentiates them from pneumatic valves? Let’s keep going!
2) What is a Pneumatic Valve?
Pneumatic valves are used to control the flow of compressed air in air-powered systems.
It helps in managing the circulation of air within machinery. These valves are used in automation tools, industrial machines, and other processes. You will find pneumatic valves installed in common machines around you.
Primary Components of Pneumatic Valve
Have you ever thought about the inner workings of valves? The working of these pneumatic air valves is the result of the collaborative work of their components. So, let’s briefly examine the major components that assist it in performing its functions properly.
- Valve Body: It is the outermost casing of the valve. The body is made of either plastic or thick metal.
- Actuator: It is the muscle of the operation. It controls the inner components by using air, a mechanised bolt, or hand pressure.
- Spool or Poppet: These two shift the direction of flow.
- Ports: When pneumatic tools are used, air flows in and out of the device. This is done through these certain gaps.
- Seals: Keep the valve airtight to prevent air from getting in or out due to leaking. Seal optimises valve performance.
➔ How It Operates
A pneumatic valve operates by moving internal components that control air flow with compressed air. The entering air moves the spool or piston so ports can be opened or closed, which allows systems to function effectively by directing the flow of air, resulting in the proper operation of machines.
Types of Pneumatic Valves:
Different kinds of pneumatic valves are available in the market, and they all function uniquely. Let’s visit the primary categories and their functions.
i) Directional Control Valve
It alters the direction of airflow by either opening or closing various doors to airflow. Commonly used for function control over cylinders and actuators using 2/2, 3/2 and 5/2 valves.
ii) Flow Control Valve
Controls the speed of pneumatic actuators by controlling the flow of air. It assists in slowing down or speeding up motions in machines, and often works with a needle-like structure that can be adjusted.
iii) Pressure Control Valve
Sets or controls the level of air pressure within a system. It consists of regulators, relief valves, and sequence valves for a level of pressure with regard to the efficiency and safety to be maintained in operation.
iv) Non-Return (Check) Valve)
Permits any compressed air to move in a single direction but stops backwards movement from occurring. It prevents any equipment from being damaged and maintains the system free of back-pressure difficulties.
v) Shuttle Valve
Two sources of air may be connected to one outlet. The centre may permit to pass of the source which has more pressure. Helpful under safety or dual control systems to switch between air supplies.
vi) Quick Exhaust Valve
They help in releasing air fast from the cylinder to increase the speed of motion. It reduces the time cycle of the motion by releasing the air from the actuator by itself rather than through the control valve.
3) Key Differences Between Solenoid and Pneumatic Valves
Knowing the advantages and disadvantages of both solenoid and pneumatic valves allows you to choose one that sufficiently meets your requirements. Let’s look at each type and its differences.
a) Working Mechanism
Solenoid Valve: These valves work automatically. These valves move power through the coil, producing a magnetic field that moves the plunger within, which controls the flow of liquid or gas.
Pneumatic Valve: Pneumatic valves utilise pressurised air for the movement of internal components. The pressure moves the valve’s mechanism to open or close the passage.
b) Source of Power
Solenoid Valve: These need electric power, which could be 12V, 24V, or even 220V; they are thus suited for remote or automated systems.
Pneumatic Valves: These valves employ compressed air and are therefore best suited for industrial plants and other facilities that already utilise air pressure systems.
c) Speed and Precision
Solenoid Valve: These valves offer speed and precision in control. Because they respond to electrical signals immediately, they are perfect for situations where timing is crucial.
Pneumatic Valves: While fast, they are best suited where exact control is not critical, such as turning the air supply on and off at the set time.
d) Maintenance
Solenoid Valve: Regular checks for damage to the coil are necessary. These valves are easier to replace.
Pneumatic Valve: Usually more durable, but requires dry air to avoid clogging or corrosion from building up inside the valve body.
e) Best Use Case
Solenoid Valve: Perfect for applications that require rapid switching and automation, such as sprinkler controls or HVAC system management.
Pneumatic Valve: Most effective for industrial applications, particularly where pre-existing air systems are integrated, like on assembly lines or robotic arms.
| Features | Solenoid valve | Pneumatic valve |
| Power source | Electricity | Compressed air |
| Control type | Electric | Mechanical (Air-drawn) |
| Speed | Very fast and precise | Fast but less precise |
| Maintenance | Need an electric check | Require a clean air supply |
| Ideal application | Automation, HVAC, fluid control | Industrial, machinery, air control |
4) Advantages and Disadvantages of Solenoid Valves and Pneumatic Valves
When comparing solenoid valves with pneumatic ones, you need to know that each type performs best in different areas. So, let’s go over the advantages and disadvantages of valves to make the best decision.
Advantages of Solenoid Valves:
+ Response Time: All solenoid valves operate within milliseconds of receiving an electrical signal. Solenoid valves are perfect for time-bound operations.
+ Automation: Sensor and timer-based automation systems have made life easier. Since solenoid valves are electrically operated, they can be integrated easily.
+ Size: Compactness releases a lot of burden when fitting into machines that require automation. Such valves solve the problem due to their small size.
+ Power Consumption: Everybody aims to use fuel-saving systems. Solenoid valves are the best bet since they are economical in controlling electricity.
+ Control: These valves are ideal for tasks that require a high degree of precision in controlling airflow or fluid flow, such as rapid cycling.
Disadvantages of Solenoid Valves
_ Environment: The solenoid valves have limited functionality when it comes to their use in challenging environments. Performance may degrade even in the presence of a slight amount of dust.
_ Heat Build-up: The model of lower-quality solenoid valves can easily overheat after extended use and generate an intolerable amount of heat.
_ Power Constraints: Solenoid valves have less powerful systems that work under low pressures.
Advantages of Pneumatic Valves
+ Durability: Compared to rapidly used valves, solenoids have longer lifespans as they are continuously operated.
+ Strength: Equipped with the ability to withstand extreme forces and large volumes of air, pneumatic valves are a better choice for heavy work.
+ Easy to Maintain: With fewer electrical components, they suffer less mechanical failure.
+ Safe in hazardous areas: Does not pose any risks from sparks or electricity.
Disadvantages of Pneumatic Valves
_ Slower response time: With less speed than solenoid valves, they are less responsive.
_ Need for compressed air: This requires an entire system, which increases total expenditure.
_ Less exact: Better suited for jobs that do not require a high level of control.
Knowing these pros and cons helps choose appropriately from the available selection of valves using various criteria such as speed, power, and safety.
5) Applications by Industry
In automated systems, both solenoid and pneumatic valves play crucial roles. Together, they ensure dependable and effective functions across various fields.
- Manufacturing & Automation
Solenoid Valves: Control fluid and gas flow in CNC machines and cooling systems. Best suited for one-off timed events and repeat delivery tasks.
Pneumatic Valves: Drive air-operated tools and serve clever cylinders and actuators – they supercharge responsiveness for component clamping, pressing, and transport.
- Agriculture
Solenoid Valves: Mechanically aid in irrigation, misting, and fertiliser applications to conserve water and labour.
Pneumatic Valves: Power sprayers, seeding tools, and other air-driven equipment to optimise bulk farming operations.
- Medical & Healthcare
Solenoid Valves: Apply in ventilators, infusion pumps, and dialysis machines– guarantees precise control.
Pneumatic Valves: Move hospital beds, rehab tools, and surgical equipment, allowing gentle and precise motion.
- Automotive Industry
Solenoid Valves: Oversees fuel injection, emission control, and gear shifting.
Pneumatic Valves: Supervises air brakes, operating systems for tires, and robotic welding arms in assembly lines.
- Oil & Gas / Chemical
Solenoid Valves: Supervise dangerous fluids in emergency shut-off and flow control systems.
Pneumatic Valves: Power actuators and pressure relief valves in restricted electrical use zones for safety.
- Water Treatment
Solenoid Valves: Present in the processes of filtration, softening, and chemical dosing.
Pneumatic Valves: Control sluice gates, sludge and tank back flushing flow, and tank back flushing with very little servicing.
- Food and Beverage
Solenoid Valves: Control beverage dispensing, filling of liquids, and sanitation procedures with FDA-approved materials.
Pneumatic Valves: Control the risk-free contamination of sorting, bottling, and packaging machines.
- Aerospace
Solenoid Valves: Control the flow of fuel, system de-icing, and engine pressurisation.
Pneumatic Valves: Control the operation of high-reliability cabin pressure units, cargo doors, and emergency actuated mechanisms.
6) BLCH solenoid valves
BLCH Pneumatic provides high-grade valves of air and solenoid controls for industrial automation. We develop 2V, 3V, 4V, and 4M series, which are power efficient with low consumption and quick response. These valves are made from long-lasting materials so they can be used in harsh conditions.
What sets BLCH apart is our customised solutions tailored to each specific industry, provided by our highly qualified engineering team. This is exceptionally important for B2B clients, like factories and manufacturers of automation equipment. BLCH places strong emphasis on reliability and precision. To learn more about us, you can visit blpneumatic.com.
7) FAQ
1. Why is my pneumatic solenoid not working?
A pneumatic solenoid may not work because of power supply failure, dirty parts, blockage within valve systems, faulty windings, or damaged gaskets. Check for electrical power issues, cleanliness, and for parts that need replacement.
2. How long is the life of a pneumatic solenoid valve?
A pneumatic solenoid valve has a lifespan approximated at one to three years with reasonable use. Alterations in the environment and proactive maintenance may impact longevity.
3. What is a solenoid valve used for?
The purpose of a solenoid is to control the passage of a designated liquid or gas within a system. It employs an electromagnetic coil to either switch the valve or allow the movement of gas and liquid while exercising control of the fluid or gas.
8) Conclusion
To sum up, the use of solenoid and pneumatic valves in different industries enables accurate control of fluid and air flow. Their versatility and dependability make them crucial in manufacturing and automation. Such valves are well-engineered and carefully tailored to offer dependable and safe operations. Knowledge of the applications helps businesses enhance performance, thus improving the efficiency and reliability of systems in automated situations.
