The development of different types of pipes

In order to meet the requirements of safe and reliable operation of the water supply network, the development of pipes has two directions: fire-fighting steel-plastic composite pipes

The first is to select new pipe materials, restrict and phase out old pipe materials that do not meet the development requirements. Develop new pipes with excellent performance and good corrosion resistance, and select suitable metal or non-metal pipes according to actual requirements;

The second is to take protective measures for the surface of the pipeline, external anti-corrosion and internal lining coating to ensure the safety of the water quality of the pipeline network.

Cast iron pipes still occupies an important position in pipeline engineering, especially steel output will not decline in the next few decades (current world output is 700-800 million tons). The performance of cast iron pipes has been greatly improved. In the international standard ISO2531, the tensile strength of centrifugal ductile iron pipe is ≥420MPa, which is almost the same as that of low-alloy steel, but the corrosion resistance of centrifugal ductile iron pipe is better than that of steel pipe. In order to resist corrosion and ensure the water quality of the pipe network, the inner and outer lining and anticorrosive materials of the cast iron pipes are being improved and perfected.

Plastic pipes will have greater development, and the material properties of PVC pipes will also be improved. Avoid using stabilizers containing heavy metals. All kinds of new technologies on new plastics are continuously being promoted and used. However, the stability and aging of plastic pipes are still concerns.

Advanced composite material pipelines have been greatly developed in the 20th century. For example, prestressed reinforced concrete pipes, PCCP pipes (copper cylinder concrete pipes) and resin-based composite materials (glass pipes with sand pipe GRP) are used in large-diameter water pipeline projects; steel-plastic composite pipes and aluminum-plastic composite pipes are used in large-diameter water pipeline projects. Small-caliber user pipelines are in great demand in the market.