Drains which pass under a house must be of cast iron, the most expsive material for pipe drains. 穿过房屋下面的排水管道，必须使用铸铁管，这是排水管所用的最昂贵的材料。
This paper describes the character of vermicular cast iron pipe and the use of it in the sub-high pressure town gas pipeline. 本文重点阐述蠕墨铸铁管的性能和用于城市次高压煤气管网的可行性。
