In Japan, the traditional hot branching technique takes much time and is expensive. As a consequence, it harmfully impacts the environment. The reason lies in the fact that first this technique needs the installation of a by-pass line with gas stoppers. But, it is also needed to cut the pipe and to insert a branch joint. Moreover, the evacuation of a large volume of excavated soil can be the cause of traffic jams. Indeed the needed excavation pit's dimension is about 13 feet long. And finally, the urban underground congestion is also problematic for the gas branching construction activity. In order to remove some of these problems and create more environmentally-friendly construction, we developed the new hot branching technique. This shortens the construction time, reduces costs, and limits excavation volume. The technique is carried out with a specialized hot tapping tool and a special joint named "SSB". "SSB" is the abbreviation for "Service Sleeve Branch joint". It includes a plate that works as a gas shut-off device. The plate eliminates the need for an expensive gas shut-off device (non-blow shutter unit). Furthermore this technique reduces the needed excavation pit's dimension to just about 3 feet long. It means that this is by 75% smaller. The technique is used for steel pipe and ductile iron pipe with diameters ranging from 4 inches to 10 inches. Last advantage, by using SSB as a transition joint, the branch main can be renewed to polyethylene pipe. As a matter of fact, nowadays the new branching technique is widely used, and is adopted by 59 regional gas companies in Japan. So about 550 joints are installed every year.
展开▼
