Question

In designing of watermain, regular practice is to use supple iron for pipe size less than 600mm and to use steel for pipe size additional than 600mm. Give some specific and main reasons?

Answer

For watermain pipe size less than 600mm, ductile iron is usually used since internal welding for steel pipes below 600mm is difficult to be carried out. Furthermore, it requires only simple jointing details that allow for faster rate of structure. For watermain pipe size higher than 600mm, steel pipes are recommended as steel pipes are lighter as compare to ductile iron pipes for same material strength and so cost of steel pipes is less than that of ductile iron pipes. In adding, in areas of difficult contact lighter mild steel pipes pose benefit over ductile iron pipes for simple handling.