The quality of the steel pipe is not only related to its service life, but also related to its use efficiency. Then when we are buying steel pipes, we can roughly distinguish the quality of the steel pipes by the appearance of the steel pipes. If the surface of the steel pipes has numbness and is no

Before installing the steel pipe, the trench needs to be dug, and the soil dug after the trench has a reasonable stacking place, the excavated earth should be transported to the outside in time, and should not be too close to the trench, there must be two The distance above the meter, so as not to a