In industries dealing with volatile gases, detecting leaks promptly is crucial for safety, capacity and environmental protection. Traditional gas leak detection methods have served us well, but in hazardous environments known as Ex-zones, which are at risk of explosions, new technology like acoustic cameras is proving to be a game-changer. In this blog, we’ll explore why acoustic inspection for Ex-zones excels in detecting gas leaks and how it can enhance both safety and operational efficiency.
What are Ex-zones?
Ex-zones, or hazardous areas, are classified based on the likelihood and frequency of explosive gas or dust atmospheres occurring. For example:
- Zone 0: Where an explosive gas atmosphere is present continuously or for long periods.
- Zone 1: Where it is likely to occur in normal operation occasionally.
- Zone 2: Where it is unlikely to occur during normal operation, but if it does, it will only exist for a short time.
Due to the high risks involved in Ex-zones, safety regulations demand that equipment used in these areas must meet strict certification standards, such as ATEX or IECEx. This is where acoustic cameras offer unique advantages over traditional detection methods.
Typically ATEX certification for equipment is most commonly used inside the European Union (EU), where IECEx is globally used, including Asia, Australia and the America’s, but outside of Europe.
Human presence in Ex-zones
Aside from the restriction on equipment, the entry of maintenance staff is heavily guarded to minimize the risk of explosion. Specific restrictions are formulated per zone:
- Zone 0: Due to the constant or long-lasting presence of gas, human presence is highly restricted to specialized trained personnel and only certified explosion-proof equipment is used.
- Zone 1: Human presence is restricted to maintenance staff and operators performing periodic checks or repairs, but only with personal protective equipment (PPE) and tools. Strict safety protocols are in place and staff must be aware of the potential for explosive atmospheres.
- Zone 2: Restrictions are more relaxed than in zones 0 and 1 as routine maintenance and inspection may occur. Nevertheless, safety protocols still apply, and personnel must be trained in emergency procedures.
In each Ex-zone, protocols and safety procedures are adjusted to the likelihood of an explosive atmosphere. To keep personnel safe, the use of certified equipment is promoted.
Equipment used in Ex-zones
Finally, the use of equipment is restricted in Ex-zones to minimize the risk for triggering an explosion.
- Zone 0: Only certified equipment that is intrinsically safe and explosion-proof can be used. Fixed gas monitoring equipment is preferred, as human presence is minimized.
- Zone 1: Equipment must be designed for use in explosive atmospheres and must meet ATEX or IECEx certifications. A combination of fixed and human operation equipment is possible here.
- Zone 2: While the risk is lower, equipment must still meet safety certifications for potentially explosive atmospheres. Often, less restrictive explosion-proof or flameproof devices are used, but regular monitoring remains essential.
What indicates a possible gas leak?
Not every gas leak is easy to detect. When the gas is scentless or due to the Ex-zones scale or loudness of the site, a leaks can be inaudible and easy to overlook. There are several noticeable indicators for gas leaks, and we have listed 6 gas leak indicators:
- Unusual hissing or whistling sounds
- Smell of gas
- Dead or dying vegetation
- Higher gas bill than usual
- Physical symptoms such as headaches or nausea
- Loss in capacity
In these cases, an optical or audible indicator will tell the presence of a gas leak. But if the gas directly dissolves in the open air, it can’t be smelled, or if the site is noisy, a gas leak cannot he heard during routine maintenance and unwanted emission can continue to go unnoticed, cause unnecessary losses and a risk for explosion.
Gas leaks are often impossible to smell or hear and therefor specialized equipment is needed to reduce unwanted gas leaks. Acoustic cameras are fairly new technology to this industry, but are gaining interest for their reliability and ease-of-use.
Why is acoustic inspection for Ex-zones so suitable?
Acoustic cameras, or acoustic imaging is a very suitable technology for gas leak inspection in Ex-zones. Regular inspection can be challenging due to safety restrictions and remoteness. Here are 7 reasons why acoustic inspection is suitable for industrial Ex-zones.
- Non-Intrusive Detection
Acoustic cameras provide non-intrusive leak detection by “listening” to the ultrasonic sound waves emitted by pressurized gas leaks. They visualize these sounds, allowing for detection from a safe distance without the need for direct contact with the leak source. This is particularly crucial in Ex-zones, where direct interaction with equipment could trigger a spark and cause an explosion.
- Real-Time Visualization
One of the most valuable features of acoustic cameras is their ability to offer real-time visual feedback. Leaks are visualized as a “sound map” superimposed on a live image of the environment. In Ex-zones, this means operators can quickly identify the exact location of a leak without having to shut down the system or physically inspect every connection. With the click-of-a-button a snapshot of the leaks and its location can be saved and shared for maintenance planning.
- Efficient in Complex Environments
Ex-zones often have complex infrastructure, with pipelines, valves, and machinery all in close proximity. Acoustic cameras are highly effective in such environments because they can pinpoint even the smallest leaks amidst background noise and other equipment sounds. This feature makes them invaluable for facilities where traditional leak detection methods struggle due to complexity or access limitations.
- Explosion-Proof models
Today, there are several acoustic cameras, designed to meet strict safety certifications required for use in Ex-zones. These explosion-proof models ensure that they can be operated safely in environments where gas leaks could combine with an ignition source to create an explosion. Their rugged design and ATEX certifications make them perfect for hazardous industrial applications.
- Detects leaks invisible to the naked eye
Acoustic cameras can detect gas leaks that would otherwise go unnoticed, especially in cases where the gas is colorless and odorless, such as methane or hydrogen. They excel where traditional sensors or human inspection such as soapy water would fall short. Given that small leaks can have devastating consequences in Ex-zones, the ability to detect and address leaks quickly is a huge advantage.
- Reduced Downtime and Increased Efficiency
In many cases, Ex-zone gas leak detection requires shutting down the operation to ensure the safety of inspection teams. Acoustic cameras minimize this downtime by allowing remote, non-invasive inspections while equipment remains operational. This ensures that leaks are detected and addressed promptly without interrupting production.
- Environmental and Safety Benefits
Beyond safety, acoustic cameras help minimize the environmental impact of gas leaks by enabling faster detection and repair. Methane, a common gas in many Ex-zones, is a potent greenhouse gas. By identifying leaks early, companies can mitigate environmental harm and comply with stringent regulations, while also improving worker safety by preventing toxic exposure.
Sorama’s Acoustic cameras for Ex-zones
With a fixed monitor (Sorama L642Ex) and a handheld device (Sorama CAM iV64Ex) there are many applications for which acoustic cameras are the perfect solution for gas leak detection. Additionally, the Sorama L642Ex is suitable to be mounted on various robotic partners (ExRobotics, and others) for autonomous inspection.
Sorama is a reliable partner with decades of experience in the field or acoustics. Starting at the University of Eindhoven, we have been breaking barriers and pushing technology from our head office in Eindhoven the Netherlands. We are proud of our innovative mindset and equally proud of the acts that development, design and production are all done from within the EU, read our blog “Made in Europe” to learn more.
Which gasses can you detect with an acoustic camera?
Among the gases, detectable by a Sorama acoustic camera are:
- Methane (CH₄) – Methane leaks produce high-frequency sound emissions, especially in natural gas systems and pipelines.
- Hydrogen (H₂) – Hydrogen leaks, due to its small molecular size, often generate distinct ultrasonic sounds when escaping from pressurized systems, making them notoriously difficult to detect.
- Oxygen (O₂) – Leaks from oxygen tanks or pipes can produce detectable noise in industrial settings but are scentless causing a challenge for leak inspection.
- Carbon dioxide (CO₂) – Pressurized CO₂ leaks can be identified by the sounds they generate, especially in fire suppression or refrigeration systems.
- Nitrogen (N₂) – Nitrogen leaks, especially in cryogenic or pressurized systems, also emit detectable acoustic signals for an acoustic camera.
- Ammonia (NH₃) – In refrigeration systems or industrial processes, ammonia leaks often create sounds detectable with acoustic imaging.
- Propane (C₃H₈) – Propane gas, used in heating or industrial processes, also emits ultrasonic signals when it leaks from pressurized systems.
Aside from gases, an acoustic camera can detect water and (compressed) air leaks in pneumatic systems that produce high-frequency noise.
From how far can you detect a gas leak with an acoustic camera?
Gas leaks with a high Signal to noise ratio (SNR) may be detected from a distance up to 100 meters (328 ft). The Signal-to-noise ratio differentiates between the desired detectable sound (gas leak) and background noise. For a high SNR you can imagine a quiet outdoor area with compressed air bursting through a large leak under with large force. This is clearly audible from a large distance.
The lower the SNR for the gas leak, the shorter the distance for detection with an acoustic camera. In a quiet environment a small leak can be detected from between 0,3 – 5 meters.
Fixed, handheld and robotic gas leak inspection in Ex-zones
Acoustic inspection can be implemented throughout your maintenance plan. Whether you need fixed monitoring on a remote site, a human operated handheld device for regular gas leak inspection or an acoustic monitor mounted on your Ex-robotic platform for autonomous inspection, acoustic inspection will be an enrichment for your maintenance. Targeting unwanted emission and by that reducing cost and increasing safety.
What else can acoustic inspection do in Ex-zones?
As we have covered in this article, you can perform detailed gas leak inspection with the implementation of acoustic cameras. But there are more applications than just leak detection. For Ex-zones at energy stations, the application for partial discharge detection is of value in the early prevention of insulation failure and potential explosions.
On dangerous production sites, acoustic inspection for mechanical failure is ideal to fit into the preventative maintenance plan. By detecting acoustic anomalies caused by wear in mechanical bearings for instance, the replacement work can be planned ahead, while minimizing risk of an unsafe working environment, failure and downtime.
Customer testimonial: Hydrogen leak detection
When we say acoustic cameras are great for hydrogen leak detection in Ex-zones, don’t just take our word for it. Our customer H2 Production in Bergen, Norway was so thrilled with the Sorama CAM iV64Ex that their skepticism quickly turned into excitement. Read more in our customer testimonial.
Acoustic consultancy in Ex-zones
If your need for acoustic inspections is occasional, investing in a full inspection system may not be necessary. In such cases, a one-time consultation can provide the solution you’re looking for. Our experienced acoustic consultants utilize our state-of-the-art equipment to deliver a comprehensive sound imaging analysis. You’ll receive a detailed report, complete with actionable insights and a management-level presentation.
Conclusion
Acoustic cameras represent a transformative leap in gas leak detection, especially in hazardous Ex-zones where safety is paramount. With their non-intrusive, real-time visualization capabilities and explosion-proof designs, they offer a safer, more efficient, and environmentally friendly solution. For industries operating in Ex-zones, adopting acoustic imaging technology not only reduces risks but also drives operational efficiency and compliance with safety standards.
For more information on how acoustic cameras can enhance safety in Ex-zones, download our free ebook on acoustic inspections or contact our experts today!
