# Leaks at Flange Connections: From Detection to Technical Assessment Services September 14, 2026 by [Michael Balcerek](https://idt-gaskets.com/team/michael-balcerek) · September 15, 2026 · IDT Industrie- und Dichtungstechnik GmbH ![Hand holding an ultrasonic camera in front of a rusty flange connection, display showing the acoustic overlay](https://idt-gaskets.com/media/pages/unternehmen/news/akustische-leckageortung-flanschverbindungen/78126d718c-1789400745/service-web1-800x.jpg)![Iced valve at a flange connection, frost forming from escaping medium](https://idt-gaskets.com/media/pages/unternehmen/news/akustische-leckageortung-flanschverbindungen/eed3589773-1789400758/service-web2-800x.jpg)![Ultrasonic camera display with leak overlay at a refinery plant, reading over 75 l/h](https://idt-gaskets.com/media/pages/unternehmen/news/akustische-leckageortung-flanschverbindungen/387541e113-1789400759/service-web3-800x.jpg) Acoustic leak detection can quickly locate and document leaks after a turnaround or during plant operation. But finding a leak is only the first step. To understand what went wrong, the flange connection has to be assessed as a complete system. After a turnaround, flange connections that have been opened, cleaned, resealed and reassembled face their first real test during restart. In operation, they are exposed to pressure, temperature and changing loads. This is when leaks can become apparent. Traditional methods such as leak detection spray and visual inspection remain well established. But inspecting large plant areas or hard-to-reach connections can be time-consuming. Acoustic leak detection adds another option: scanning larger areas from a distance and then focusing on the connections that require closer attention. ## Locating leaks with ultrasound When pressurized gas escapes through a small opening, the resulting turbulent flow generates high-frequency sound. An acoustic camera uses an array of microphones to detect the sound source and overlays its location on a camera image. This allows larger sections of piping or plant areas to be scanned from a distance before individual findings are investigated in more detail. Depending on plant geometry, distance and environmental conditions, even some elevated connections can be checked from ground level. Each finding can be documented and assigned to a specific location in the plant, creating a clear basis for follow-up. [![](https://idt-gaskets.com/media/pages/unternehmen/news/akustische-leckageortung-flanschverbindungen/e4a3780bd6-1789400010/leckagesuche-02-poster.jpg)](https://idt-gaskets.com/media/pages/unternehmen/news/akustische-leckageortung-flanschverbindungen/84c8d2ea2a-1789398994/Leckagesuche-02_22Q.mp4)## After a turnaround: Checking connections during restart Restart is the point at which newly assembled flange connections have to perform under actual operating conditions. Acoustic leak detection allows larger plant areas to be screened efficiently and leaking connections to be documented for follow-up. Combined with information from [assembly, quality assurance and documentation](/unternehmen/news/flanschmontage-vom-zertifikat-zur-nachweisbaren-kompetenz), this gives operators a clearer picture of how individual connections are performing after the [turnaround](/service/turnaround). ## During operation: Finding leaks without a dedicated shutdown Acoustic leak detection can also be used during normal operation, particularly in compressed-air and gas systems. Potential leaks can be located without taking an area offline solely for the inspection. Whether this is possible in a specific case depends on the system, medium, accessibility and applicable safety requirements. ## Finding the leak doesn’t tell you the cause This is where detection ends and technical assessment begins. A flange connection is a system. Flanges, bolts and gasket have to work together under the conditions in which the connection was assembled and is operated. A leak therefore tells us where there is a problem – not why. > A leak tells us where a flange connection is failing – not why. To understand the cause, we have to look at the complete system: flange, bolts and gasket, as well as how the connection was assembled and the conditions it operates under. Michael Balcerek, Head of Flange Management at IDT Possible causes can include flange condition or alignment, bolting, gasket selection and design, assembly or operating loads. A single measurement will not necessarily identify the root cause, but it gives the technical assessment a clear starting point. ## Turning findings into better maintenance decisions The real value grows when leak locations are recorded systematically rather than treated as isolated incidents. Repeated findings can reveal patterns: similar connections showing the same problem, leaks following particular maintenance work or correlations with operating conditions. These patterns can help determine where closer technical analysis is needed. That creates a useful feedback loop: Assembly and quality assurance → Operation → Leak detection → Technical assessment → Next maintenance action Information from operation can help identify connections that need particular attention at the next turnaround. In turn, assembly and quality assurance records provide context for understanding leaks found later in operation. ## Flange integrity management beyond the turnaround As a gasket manufacturer, IDT supplies one critical part of a flange connection. But [flange management](/service/turnaround) cannot stop at the gasket. Reliable flange connections depend on the interaction between flange, bolts and gasket – from component selection and assembly through to actual operation. Acoustic leak detection adds information from that final stage. By linking what happened during assembly with what happens in operation, leak detection becomes more than a way to find leaks. It becomes another source of information for better flange management. ### FAQ: Acoustic leak detection When a pressurized gas escapes through a small opening, it can generate high-frequency sound. An acoustic camera detects these sound waves, locates their source and displays the location on the camera image. The method is particularly suitable for pressurized gas and compressed-air systems. Whether a leak can be detected depends on factors including pressure differential, leak size, distance and environmental conditions. In principle, yes. Whether a specific area can be inspected during operation depends on the system, medium, accessibility and applicable safety requirements. Acoustic cameras operate in the ultrasonic range and can filter out many common plant noises. Detection range depends on the strength of the sound source and environmental conditions. Other ultrasonic sources nearby can interfere with detection. Not necessarily. Acoustic leak detection is particularly useful for screening larger areas efficiently. Which method is appropriate depends on the application, operator requirements and applicable regulations. In some cases, combining different methods may be the best approach. No. It can show where a leak is located, but not why the connection is leaking. Flanges, bolts, gasket, assembly and operating conditions must then be assessed to determine possible causes. ## Talk to us Want to explore how acoustic leak detection could fit into your maintenance and flange management processes? Get in touch. **Contact us** ![Michael Balcerek](https://idt-gaskets.com/media/pages/team/michael-balcerek/a0316825e8-1667745834/20220603-idt-essen-124-von-1-3-400x400.jpg) ###### Michael Balcerek TAR-Management, QA/QC Specialist [ +49 170 7662861 ](tel:+49%20170%207662861)[ m.balcerek@idt-dichtungen.de ](mailto:m.balcerek@idt-dichtungen.de) Michael Balcerek, state-certified technician, is Head of Flange Integrity Management at IDT. He is committed to digital solutions and process reliability and combines practical training concepts with modern documentation. ## Newsletter Immediate insights into the practice of industry and sealing technology. Where technology lives. Information on [privacy](https://idt-gaskets.com/privacy-policy).