There are two steel pipe mainly used for urban gas pipeline, including seamless steel pipe and welded steel pipe. The intensity of seamless steel pipe is high, but it is generally the small diameter below DN200 steel pipe as the constraints of production process and cost. There are more types of welded steel pipe, according to the welding method that can be divided into straight welded steel pipe and spiral welded steel pipe two categories. Among them, straight welded steel pipe includes Longitudinal Submerged Arc Welded pipe (LSAW steel pipe), Electric Resistance Welded pipe (ERW steel pipe) steel, and so on. For urban gas line installation, Prime Steel Pipe provides Seamless steel pipe, LSAW steel pipe, ERW steel pipe, Spiral steel pipe various types of steel pipes for selection.
According to the difference of gas pressure, city gas pipeline can be divided into low pressure (no higher than 0.01MPa), medium pressure (0.01 ~ 0.4MPa), secondary pressure (0.4 ~ 1.6MPa) and high pressure (1.6 ~ 4.0MPa). Different uses, different pressures and different diameter of the pipelines determine that urban gas pipelines have different materials and different processes.
In city gas pipeline network, high pressure pipelines, sub-high-pressure pipelines and gas transmission pipe generally select steel pipe, but there are also the problem of steel pipe type choice. In recent years, LSAW steel pipe has tended to gradually replace spiral tubes in higher pressure pipelines. At present, the price of ERW steel pipe is lower than the price of spiral welded pipe, and the quality of reliability is higher than the spiral welded steel pipe, the former has a good cost performance and its application is more and more widely. There is a way to take the pipe: when the diameter ¢ ≤ 406mm, choose ERW steel pipe, when the diameter ¢> 406mm, choose LSAW steel pipe.
In the low pressure and medium pressure pipeline, PE pipe has good flexibility, and it is corrosion-resistant, pipe wall of it is smooth and other advantages. But when the pipe diameter is larger, greater than the economic limit of PE pipe diameter, you should use steel pipe. For example, the medium-pressure pipe above DN200 is mainly using ERW steel pipe.
