Technocrats Institute of Technology & Science.pptx

Water distribution system

1. Technocrats Institute of Technology & Science Water Distribution System & Management System

2. Under the Guidance of Rahul Sir Made By Shubham Solanki Ashish Gurjewar Shivam Badholia

3. Contents Introduction Types Of Distribution 2.1 Gravity System 2.2 Pumping System 2.3 Duel System Layout Distribution System 3.1 Dead end or Tree System 3.2 Grid Iron System 3.3 Circular System 3.4 Radial System Pressure in the Distribution System Valves and Fittings Design Of Distribution System 6.1 Manual Design 6.1.1 Design of Pipe Lines 6.1.2 Analysis & Design of Pipe Network 7. Conclusion

4. 1. Introduction Water is Natural substance which is a necessity of each person .Now a days water is distributed it with in number of houses ,estates and public places by means of network of distribution system. The distribution system consist of pipes etc. The following are the requirements of a good distribution system. 1. It should convey the treated water up to the consumers with the same degree of purity. 2. The water should reach to every consumer with the repaired pressure head . 3. Sufficient quantity of treated water should reach for domestic and industrial use. 4.It should be economical and easy to maintain and use . 5. It should able to transport sufficient quantity of water during emergency such as fole fighting etc. 6. During repair work, It should cause obstruction to the traffic. 7. It should be safe against any future pollution. 8. The quantity of pipes laid should be good and it should not trust.

5. 2. Types Of Distribution System For efficient distribution it is required that water should reach to every consumer with repaired rate of how, Depending upon the methods of distribution ,the distribution system is classified as follows Gravity System . Pumping system . Dual System on combined Gravity and pumping system . 2.1 Gravity System When some ground sufficiently high above the city area is available . This can be best utilized for the distribution system in maintaining pressure in water pipes .The water flows in the mains due to quaitational force . As no pumping is repaired . There force it is the most reliable or the distribution system of water . The water head is available at the consumers door is just minimum required and the remaining head is consumed in friction and other losses.

6. 2.2 Pumping System Pumping system is types of water distribution system .It is used where the gravity method can not work

7. 2.3 Combined Gravity And Pumping System combined gravity and pumping system is most common system .Treated wire is elevate and store in distribution reservoir .Then it is transferred consumer by gravity .The excess water during low demand period is stored in reservoir and get supplied during high demand period. It is economical efficient system .

8. 3. Layout Distribution system Layout distribution system is types of distribution system which provides water distribution system in four ways. Dead end or Tree system circular iron system . Radial System Circular System Grid Iron System. 3.1 Dead end or tree System . Dead end or tree system, It is a system in which each street or block is supplied separately from the main. So there is end of system at each end of block. This type of system is good for a city which has been developed haphazardly. As it Required less number of valves .Disadvantages of this system is that large area cutoff During repairing . when the tap is not opened for a long time ,bacterial growth may take place.

9. 3.2 Grid Iron System Grid iron system is, the whole distribution system is interconnected . So the water remains in circulation and there is no contamination of water . Because water does not stand still at any point and it continues circulation. In this system, as the whole system is interconnected the water can reach from more than one direction .It provides better quality of water and during the repairing the lesser area is cutoff. Disadvantages of this system is that a lot of valve cut off a small area in case of accidental hazards. This system is also difficult to design.

10. 3.3 Circular Distribution This system is also called as ring distribution system. In this system the supply main is laid all along the peripheral roads and sub mains branch out from the mains. This system is also follows the grid iron system with flow pattern similar in character to that of dead end system. In this system determination of pipes becomes easy.

11. 3.4 Radial type System Radial water distribution system is a type of system in which the area is divided in different zones .The water is pumped into the distribution reservoir kept in the middle of each zone and the supply pipes are laid radialy ending towards the periphery . It gives quick service and the calculation of pipe sizes easy .

12. 4. Pressure in Distribution System When the water enters in the distribution main, the water head continuously is lost due to friction in pipes ,at entrance of reducers due to valves , bends , meters etc till it reaches consumers tap . The net available head at consumer tap is the head at entrance of water main minus all 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 grater the head the more will be the height up to which will be rise .If adequate head is not available at the connection to the building. The water will not reach the upper storeys to overcome this difficulty the required effective head is maintained in the street pipe lines. The water should reach each and consumer therefore it should reach on the uppermost storey .The pressure which is required to be maintained in the distribution system depends upon the following factors . The height of highest building upto which water should reach without boosting .

13. 2. The distance of locality from the distributer reservoir. 3. The supply is to be metered or not .Higher pressure will be required to cmpensate for the high loss of head in meters. 4. How much pressure will be required for fire –hydrants. 5.The funds available for the project work. Sometimes the design pressure is determined from the fighting requirement .In some cities and towns the fire fighting squads are equipped with pumping sets fitted on the vehicles for lifting the water at the site itself . At such places there design pressure may be determined by the minimum required by the consumers . But in most of town in India the people living at 2 nd , 3 rd or 4 t h storey face lots of difficulties due to non-supply of water in their storiys . At such places small lifting pumps may individually used which directly pump the water in their water lines. In multistoreyed structures the following pressures are considered satisfactory : up to 3 storeys - 2.1 From 3 to 6 storeys - 2.1 to 4.2 kg/cm^2 From 6 to 10 storeys - 4.2 to 5.27 kg/cm^2 Above 10 storeys - 5.27 to 7 kg/cm^2 While designing pipes of distribution system the following point should be kept in mind : 1. The main line should be designed to carry 3 times the average demand of

14. City . 2. The service pipes should be able to carry twice the average demand. 3. The water demand at various points in the city should be noted. 4. The length and sizes o each pipe should be clearly / marked. 5. The pressure drops at the end of each line should be calculated and marked .

15. 5. Valves and Fittings Valves are required to control the flow of water, to regulate the pressure to release or to admit air and to prevent flow of water in opposite direction . In every noses vrious types of fitting such as taps bends tees sockets etc. are required for distribution and forming network the pipes insides the noses standards specifications for most commonly used pipes insides the noses standards specifications for the most commonly used valves are published by Indian standard institution. 5.1 Sluice Valves There are also known as gate valves and most commonly used in practice .These valves are cheaper offer less resistance to flow of water than other valve used for same purposes . Gate valves control the flow of water through pipes and fixed in main lines bringing water from source town at 3 to 5 kms intervals thus dividing the pipeline into different section .this valves is made of cast iron with bran bronze and stainless steel. It mainly consist of a wedge shaped circular disc fitted closely in access against the opening in the valve.

16. 5.2 Pressure Relief Valves These valves relieve high pressure in pipe lines .Figure illustration such type of valve which is intended excessive pressure that may build up in a closed pipe. It is essentially consists of a disc controlled by a spring which can be adjusted for any pressure when the pressure in the pipe line exceeds the desired pressure ,the disk is forced off from its seat and execceive pressure is relived through cross pipe ,after this disc comes down automatically due to force of spring.

17. 5.3 Check Valve Check valve are also called as reflux valve are non return valve and are automatic devices which allows water to flow only in one direction and prevent it from flowing in reverse direction .The arrow indicates the direction of flow of water when the water flows the disc rotates round the hinge and remain in a horizontal plane. The water therefore passes off without any obstruction now if the flow reveres the disc automatically falls down by rotating round the hinge and remains tightly pressed against the valve seat buy the pressure of water to flow in reverse direction .

18. 5.4 Air Relief Valve When the valve enters in the pipe lines ,It also carries some air with in which lends to accumulate at high points pipe .These valves consists of a cast iron chamber bolted on the pipe over the opening in the crown These valve are automatic .

19. 5.5 Drain Valve In this summits .It is possible that some suspended impurities may settle down and cause obstruction to flow of water . In the distribution system at dead ends if water is not taken out it will is not taken out it will stagnate and bacteria will be born in it .To avoid the above difficulties drain valves are provided at all such points .When drain valve is opened the water rushes at all such points .When drain valve is opened the water rushes out thus removing all the slit ,clay etc from mainline

20. 6. Design Of Distribution System 6.1 Manual Design The layout of city or town, topography etc will greatly effect the layout and design of distribution system . The existing population expected future population and design of distribution system .The existing population expected future population commercial and industrial present future water requirement all have to be considered in the layout and design of distribution system . The main work in distribution system design is to be considered the sizes of the distribution pipes which will carry the repaired quantity o water at the desired pressure. 6.1.1 Design of Pipe Lines Till date no direct are available for the design of distribution pipes while doing the design first of all Dia of the pipes are assumed the terminal pressure heads which could be made available at the end of each pipe section after allowing for the loss of pressure head in the pipe section when full peak flow discharge is flowing in each pipe section when full peak flow is discharge is flowing are determined .The determination of the friction losses in each pipe section is done . The total discharge flowing through main pipe is to be determined in advance.

21. Hazen William method for determining the velocity of pipes V=0.85C H R 0.63 S c-54 Head loss due to friction is determined by HL=1÷1094( Q÷Ch )1.85L÷Q^4.97 6.1.2.Analysis & Design of pipe network In this distribution system for any closed network of the pipes the following conditions must be fulfilled. The quantity of water entering a junction, must be equal to the quantity of water leaving the same junction .In other words entering flow must be equal to the leaving flow . i .e low of continuity is satisfied. The algebraic sum of the pressure drops round closed loop must be zero.i.e there shall be continuity in the pressure Following are the various method for the analysis of flow in pipe networks. Circle method Equivalent pipe method Electrical Analogy method Hardy cross method

22. Hardy Cross Method In this method the correction are applied to the assumed flow in each successive trail . The head loss in each pipe is determined by pipe flow formula . Now it Qa be the assumed flow in a pipe and Q be the actual flow in that pipe, then correction will be given by the relation = Q= Qa Q= Qa+ If the head loss in the pipe under reference is H L it can be determined by the formula H L = kQ a When k is a constant depending upon the size of the pipe and its interval condition. The head loss can also be determined by hazen william formula in this term. As a common practice positive sign is given to the head losses in anti clock wise direction and negative sign to those in the anticlockwise direction. The minor losses are usually naglected . In case of network of pipe having many loops, the system must be divided into two or more loops such that in the network is included in the circuit of one loop. We have adopted hardy cross method for analysis of pipe network. The results obtained by the manual design is tabulated below: Since the result obtained by manual method is found to be more economical then the latter due to have adopted the manual method in our design of pipes

23. 7. Conclusion Result of distribution system from manual and software show that there is a difference between them. Computer software sophistical package which consider so many factor regarding the distribution system. Hence it gives economical design as compare to manual design . In design hardy cross method is most widely used method ,But it is too much time consuming and so many iteration are required.