Three employees of the Wuppertal public utility company have developed a simple solution for finding leaking gas pipes. Their gas diffusion sleeve is already in use in several cities (Fig. 1).
Safety is the top priority in gas supply. This is why gas supply companies constantly check the pipes in their networks for leaks. As a rule, street caps are used as test points and to visualize the pipe runs.
If gas supply pipes are leaking, the gas collects under the sealed surfaces. In the past, gas caps with sniffer pipes were installed in roads and sidewalks. With the help of these street caps, special equipment was able to detect gas leaks. Everyone has seen the square iron caps with an edge length of 15 cm in the street scene. However, they have disadvantages: They were costly to install and on road surfaces they suffer from vehicle traffic. They sag or the asphalt at the edges crumbles.
The three WSW employees André Ernestus, Ali Tahiri and Jörg Clausdorff (Fig. 2) have found a simple and practical solution for gas leak detection that avoids these disadvantages: the gas diffusion sleeve. The 25 cm long tubes are simply hammered into a small borehole in the asphalt. With the gas diffusion sleeve, gas concentration measuring devices respond to escaping gas via the radial grooves and a small hole in the sleeve head. Additional elongated holes in the shaft serve as inflow openings with a lower surface thickness. This has considerable advantages, especially in city centers, as the road surface remains largely untouched. There is no need for costly road construction.
For Wuppertal, the gas diffusion sleeve is an ideal solution for gas leak detection. As a result of the destruction of the Second World War, many places in the Bergisch city still have disturbed ground with the remains of brickwork and old pipelines. Concrete was often used as a substructure for paved surfaces or extremely thick bituminous surfaces were used. The gas diffusion sleeve is ideally suited for these almost gas-impermeable surfaces. Until now, measurements could only be taken at interruptions, cracks and kerb joints. However, precise positioning of the gas diffusion sleeves along the route enables measurements to be taken directly at critical points.
Wuppertaler Stadtwerke has installed the invention of its three employees at several locations in the city. WSW also took care of applying for a patent for the innovation and is providing sales support. In the meantime, other gas network operators have also become aware of the gas diffusion sleeve. The small tubes from Wuppertal can also be found on the streets and in pedestrian zones in Fürth or in Breda in the Netherlands. Large gas suppliers have also fitted transport pipelines with the tubes.
“The idea for developing the gas diffusion sleeve arose from practical experience and has proven its worth,” say the inventors. It not only has technical advantages, but also saves money. The uncomplicated and quick installation without complex civil engineering work reduces costs. In addition, less consequential damage is to be expected on busy roads. The sleeves can also be used flexibly and are a benefit for safety. WSW's sales partner is Burger Armaturen.
