用铸铁管做下水管除了人们已知的缺点外 ,还有一个鲜为人知的缺点 ,即下水管总想往下“溜”。有些设计人员设计的下水管每隔三层才设一锚固 ,由于铸铁管很重 ,锚固件年久锈蚀 ,承受不住下水管自身的重量 ,便悄悄地、缓慢地往下“溜” ,使水平向与竖直向下水管的连接处断裂漏水 In addition to the known shortcomings of using cast iron pipe to make sewer pipe, there is a little-known shortcomings, that is, the sewer always want to “slip down.” Some designers design the sewer pipes to be anchored every three floors. Since the cast iron pipes are heavy and the anchors are rusty for a long time, they can not withstand the weight of the sewer itself, so they quietly and slowly “slide” Water leakage to the connection to the vertical down pipe