Layout of Distribution System: Pipes except the service connections are usually made of cast iron with some type of coating to avoid rusting where as foe service connection galvanised iron pipes are used. Dead end system: Also known as tree system, it has one main pipe from which various submains bifurcate and from submains, laterals comes out. It is easy to design, cheap and simple but due to dead ends, free circulation of water is prevented. Grid-iron system: Here the mains, branches and laterals are interconnected hence dead ends are eliminated and water can reach to a location through more then one route. Pressure throughout the grid system is equal. Ring system: It has main pipe all over the area. Thus, it has smaller branches and laterals, and has lesser number of valves. Hence cheaper as compared to grid system. Radial system; A big area is divided into several zones and at the centre of each zone, a distribution reservoir is kept. Thus it has zonal distribution.