What Is the Difference Between 5/2 and 3/2 Solenoid Valves?

Kelm Solenoid Valves from a South East Pneumatics Supplier

When it comes to regulating the flow of air or liquid in industrial systems, solenoid valves play a crucial role. Yet, not all solenoid valves are created equal, and selecting the right one can be critical for the efficiency and safety of your operations. Among the different types, 5/2 and 3/2 solenoid valves are commonly used, but they serve different purposes and operate differently. Understanding these differences is essential, whether you’re an engineer looking for the most efficient solution or a procurement specialist trying to find the best value for your budget.

At Fluid-Air Components Ltd, we have years of expertise in supplying a wide range of pneumatic products, including solenoid valves. We are committed to helping you make informed decisions that best meet your needs.

In the upcoming section, we will delve into the terminology often used when discussing these types of valves to lay a foundation for the deeper analysis to follow.

Valve Terminology in the Context of Solenoid Valves

Understanding the jargon is the first step in any technical decision-making process. The terminology used in solenoid valves, such as “5/2” and “3/2,” may appear complex, but these figures are essentially shorthand for describing the valve’s configuration and functionalities. In these notations, the first digit indicates the number of ports that the valve has, while the second digit signifies the number of states or positions the valve can adopt.

A 5/2 solenoid valve, for example, has five ports and two states. Similarly, a 3/2 solenoid valve has three ports and two states. The terms ‘monostable’ and ‘bistable’ frequently crop up as well. A monostable valve has one stable state and requires power to shift to another state, while a bistable valve can remain stable in two states, even without power.

As a trusted supplier of high-quality pneumatic products, Fluid-Air Components Ltd offers valves that adhere to these configurations, with the added advantage of being able to cross-reference applications to products for the best solution. We place a strong emphasis on quality and can offer expert guidance to help you navigate these technical details.

Next, we will explore the key differences between 5/2 and 3/2 solenoid valves, focusing on their distinct features and applications.

Key Differences Between 5/2 and 3/2 Solenoid Valves

Now that we have a grasp on the basic terminology, let’s delve into what sets 5/2 and 3/2 solenoid valves apart. The primary differences lie in their configurations and, subsequently, their applications.

A 5/2 solenoid valve, with its five ports and two states, is typically used in applications requiring the control of double-acting actuators. This valve allows for more complex operations and greater flexibility in directing flow. On the other hand, a 3/2 solenoid valve, with its three ports and two states, is generally employed for single-acting actuators. These valves are simpler and often used in applications where basic on-off functions are needed.

Another essential aspect to consider is that 5/2 valves usually require a greater power supply due to their complex functionalities, while 3/2 valves are more energy-efficient but offer less flexibility.

Fluid-Air Components Ltd excels in providing a diverse range of these valves, each rigorously tested to ensure maximum performance and durability. Our technical team can assist you in choosing between these valve types based on your specific application needs.

In the section to follow, we will take a closer look at the different types of 5/2 solenoid valves, breaking down their unique features and advantages.

Types of 5/2 Solenoid Valves

As we navigate further into the realm of 5/2 solenoid valves, it’s important to understand that this category itself offers a variety of types designed to meet specific functional needs.

5/2 Single Coil Monostable Solenoid Valves

A monostable valve in the 5/2 configuration utilises a single coil and has one stable state. When energised, the valve switches to its secondary state, reverting to its original stable state once the power is removed. These types of valves are generally used in applications requiring quick, short-term actuation.

5/2 Manual Reset Solenoid Valves

These valves offer an added layer of safety, reverting to a predetermined position when power is lost. They require manual intervention to reset, making them ideal for critical applications where unintended movements could be hazardous.

5/2 Double Coil Bistable Solenoid Valves

Double coil bistable valves have two stable states and two coils, allowing for more complex control scenarios. They remain in their last commanded position even after the power supply is interrupted, offering flexibility in sequence-based operations.

The below pictures represent 5/2 solenoid valves, the valve on the left is a 5/2 single coil monostable configuration and the valve on the right is a 5/2 double coil bistable configuration.

5 2 Sol Spring
5 2 Sol Sol

Fluid-Air Components Ltd provides all these types of 5/2 solenoid valves, incorporating quality assurance tests and backed by our in-depth technical expertise. Our range allows us to offer solutions customised to your application’s unique demands, ensuring you get the most effective and reliable product.

In the next section, we will explore the different types of 3/2 solenoid valves, including their features and the applications they are best suited for.

Types of 3/2 Solenoid Valves

Switching gears to 3/2 solenoid valves, it’s evident that these more streamlined valves also come in multiple configurations to fit various needs. Despite having fewer ports and states compared to their 5/2 counterparts, these valves are versatile in their own right.

3/2 Normally Closed Solenoid Valves

In this configuration, the valve remains closed when de-energised and only opens when electrical power is applied. This type of valve is often used in applications where the default position needs to be in a closed state for safety or functional reasons.

3/2 Normally Open Solenoid Valves

Conversely, these valves remain open when there’s no electrical power and close when energised. They are ideal for systems requiring a default open position, often for the purpose of draining or ventilation.

3/2 Single Coil Monostable Solenoid Valves

Similar to its 5/2 monostable counterpart, this 3/2 valve has one stable state. Upon energisation, it transitions to its secondary state and reverts to the original position once the power is removed. This makes the 3/2 normally closed solenoid valve exceptionally well suited to critical safety applications where when power is lost the spring shuts the valve off.

3/2 Double Coil Bistable Solenoid Valves

With two coils and two stable states, this valve offers a level of flexibility in control, albeit less complex than its 5/2 equivalent. It retains its last position even when power is lost, making it useful in specific automation tasks.

The below pictures represent 3/2 solenoid spring valves, the valve on the left is a normally closed configuration and the valve on the right is a normally open configuration. Although they look identical the pneumatic schematic under each valve is the give away.

3 2 NC Sol Spring
3 2 NO Sol Spring

At Fluid-Air Components Ltd, we take pride in offering a comprehensive range of 3/2 solenoid valves. Our technical team is always on hand to provide expert guidance, ensuring that you select a valve that is tailor-fit to your application’s requirements.

In the following section, we will leverage our extensive experience to guide you in choosing the right valve for your specific application.

Navigating the Best Valve Solution for Your Application

Selecting the right solenoid valve is not just about understanding its types and functionalities; it’s also about aligning those features with your specific requirements. Various factors such as the media being controlled, the operating environment, and the required flow rates must be considered.

Fluid-Air Components Ltd distinguishes itself in this regard. Our sales team possesses the technical knowledge to cross-reference applications to products, helping you arrive at the most effective solution. Even if you initially thought a 5/2 valve was right for your system, our expertise might suggest a 3/2 valve as a more efficient or cost-effective choice, or vice versa.

Our commitment to customer-centric service ensures that you not only get the right product but also a solution that genuinely fits your needs, backed by our assurance of quality and reliability.

Next, we’ll discuss how you can get in touch with us for more personalised information and expert advice on making your valve selection.

Contact Us for Expert Advice

If you’ve read this far, it’s clear you’re serious about making an informed decision when it comes to selecting the right solenoid valve for your application. But even with all this information, there may still be specific questions or unique requirements that you have. That’s where the benefit of personalised, expert advice truly comes into play.

At Fluid-Air Components Ltd, we go beyond supplying products. We’re dedicated to offering total solutions, and that starts with understanding your specific needs. Our technical team is readily available to offer you customised advice, leveraging our extensive experience and a deep understanding of solenoid valve technologies.

Whether you need further clarification on valve types, have questions about compatibility with your existing systems, or require a full-scale consultation for a new project, we’re here to assist you. Feel free to reach out to us through our website, via email, or by giving us a call. Our expert sales team is geared towards offering you the most efficient and effective solutions, fully aligned with your operational goals.

In the concluding section, we’ll summarise the key takeaways from this guide to assist you in your decision-making process.


As we’ve navigated the complexities of 5/2 and 3/2 solenoid valves, it’s apparent that understanding the differences and specific types is just the first step. The ultimate goal is to align this knowledge with your unique application needs, something that often requires expert advice and a wide range of product options.

Fluid-Air Components Ltd is committed to being more than just a supplier; we aim to be your go-to solution provider for all your pneumatic needs. With a rich portfolio of solenoid valves from various manufacturers and a technically adept team at your service, we are well-positioned to guide you in making the most suitable choice.

We hope this guide has been instructive and aids you in your selection process. Should you require further assistance, don’t hesitate to reach out to us. Your success is our mission, and we’re here to ensure you achieve it.

Thank you for taking the time to read this guide. We look forward to partnering with you on your next project.

Enjoy this and want to learn more? Next up is What is the difference Between 5/2 and 5/3 Solenoid Valves.