2. Network Appurtenances Major operations within a water transport and distribution systems are: 1. Transmission. 2. Storage. 3. Pumping.

4. 1. Increased water losses. 2. Increased energy losses. 3. Shorter pipe life time. 4. Expensive maintenance of the system. 5. Potential deterioration of water quality.

5. Pipes can be classified as follows according to the purpose they serve : 1. Trunk Mains : This is a pipe for the transport of potable, clean water from the water treatment plant or the water resource to the distribution area. 2. Secondary Mains : These pipes provide the basic structures of the distribution system. They are used to link main distribution pipes with the serves reservoirs or/and with the trunk distribution mains. 3. Distribution Mains : These pipes carry water from the secondary mains to the smaller consumers. 4. Service Pipes : These pipes bring water from the distribution mains directly to either a public stand post, yard connection or to a dwelling.

6. Pipes used in water supply are made of various materials and depending on their resistance to the backfill and shock loads they can be categorized in three large groups: 1. Rigid ( Iron, Pre-stressed concrete, Asbestos cement ). 2. Semi-rigid ( Steel, ductile iron ). 3. Flexible ( PVC, PE, HDPE, glass reinforced plastic, etc…).

12. The required volume of Tanks To calculate the capacity of the tank. Three quantities must be taken into consideration: 1. The needed supply (equals to the calculated demand). 2. Water quantities needed for the emergent maintenance, emergency storage is provided to sustain the communities needs during periods when the inflow to the reservoir is shut off, for example through the failure of the supply work, failure of pumping equipment, or need to take a supply line out of service for maintenance or repair. 3. Water quantities needed for fires.

13. Position of Tanks There are some points must be considered when choosing the location of the tank: 1. The position should be at the center of the city and close enough to the consumption points, the central locations decreases friction losses by reducing the distance from supply point to the area served. 2. It must be at a high level in order to give sufficient pressure in the system they are to serve.

18. A Water Network simulation implies the calculation of all the network pressure heads and flows together with reservoir levels, and for known pump and valve controls and consumer demands. Network simulations, which replicate the dynamics of an existing or proposed system, are commonly performed in the following situations : 1. When it is not practical for the real system to be directly subjected to experimentation, or for the purpose of evaluating a system before it is actually built. 2. To predict system response to events under a wide range of conditions without disrupting the actual system. 3. To anticipate problems in an existing or proposed system and solutions can be evaluated before time, money and materials are invested.

24. Questions