... ,colding,cutting etc.many possesses,and presently substitute for the traditional castiron pipe of buildings,which is vastly ... with the traditional castiron pipes1,The density of PVC pipe is the 1/5-1/6 of that of ... castiron pipe, light weight,convenient for transporting,stevedoring,and installing,which sharply lowering the ... .07mm/m.°c,little affected the defections; PVC-U pipe fittings