Fluid flow line-stopping methods in pipelines

One of the essential issues in the operation and maintenance of pipelines in industry is the line-stopping of fluid flow in the pipeline to carry out downstream repairs during incidents such as breakage or the need to make changes in the pipeline to add a new line, replacing the pipeline, installing a new valve or flange in the pipeline. Various line-stopping methods are used in drinkable and undrinkable fluid in pipelines, such as hot tap, pipe freezing, and inflatable pipe plugs. However, these methods cannot be used in all types of fluids and variable pipe diameters, and they can increase maintenance time, waste valuable fluid such as drinking water, or increase costs. In addition to explaining the different methods of line-stopping in pipelines in various industries, this paper describes the problems and limitations of using each one.