In the case of very large sized industrial technological pipe fitting we introduced the pipe bridge fitting system, which means that the large size steel structures (of the size that may be still transported on road) may be made in the pre-manufacturing hall and within it there may be all the ready fitted pipes, which may be assembled into a coherent pipe network with two welding seams each after having lifted them to the place of the pipe bridge. This pipe bridge building system that represents a higher technical level on one hand allows the preparation of interim welding seams and their inspection to be implemented under workshop conditions, and on the other had the large-block building method significantly speeds up onsite fitting and makes it more successful.