The traditional way of pipeline connection between welding and flange requires not only welding workers with corresponding skills, but also time-consuming, difficult operation  and pollution of welding fume. Due to the different operation space and welding skills, it is difficult to achieve satisfactory results in welding quality and appearance, thus affecting the overall quality of the project. Because the multifunctional pipeline coupling is a finished product, the operation space needed in the field is small, and it can be installed in the corner of the wall. The operation difficulty is greatly reduced, thus saving the floor area and beautifying the effect of pipeline installation.