2.6 PRESSURE IN THE DISTRIBUTION SYSTEM:
When the water enters in the distribution main, the water head is lost continuously due to friction the pipes, at the entrance of reducers; due to valves, bends, meters etc. till it reaches the consumer's tap. The net available head at the consumer's tap is the head at the entrance of the water main minus all the losses in the way. The effective head available at the service connection to a building is very important, because the height up to which the water can rise in the building will depend on this available head only. The greater the head the more will be the height up to which it will rise. If adequate head is not available at the connection to the building, the water will not reach the upper storey’s (i.e. 2nd, 3rd, 4th etc.). To overcome this difficulty the required effective head is maintained in the street pipe lines (Garg, 1994).
