Cast iron pipes and fitting are primarily used for designing of soil and rain water disposal systems. These pipes are made by the sand cast process or by spinning.
They are available in 1.5, 1.8 & 2 metre length and 5 & 6 mm thickness.

There are 3 common types of plastic pipes are available in market, as given below.

GI pipes are made from steel pipes. The galvanizing process deposits a thin coating of zinc which protects it from corrosion.

They are available in light, medium and heavy grades depending on the thickness of the metal. For a 15 mm GI pipe, the thicknesses are 2.0, 2.65 & 3.25 for the light, medium and heavy grades, respectively. 

These pipes are costlier than PVC pipes.

These pipes are available in the form of internal diameters 10 mm to 600 mm with thickness varying from 12 mm to 43 mm.

These pipes are extensively used as underground drainage pipes in low cost construction buildings. 

These pipes are used for drainage of rainwater from roofs, soil and waste and also for ventilation. They come in two profiles – one with beading around socket (WB) and the other without beading around socket (WOB). The latter type is more common than the former.

The pipes come in lengths of 3 meters.