A pipe ABC connecting two reservoirs is of 75 mm diameter (as shown in figure Q4). From A to B it is horizontal and from B to C it falls 3.3 m. The lengths of AB and BC are 24 m and 15 m respectively and each length has two 90° bends in them. The water level in the reservoir at A is 3.7 m above the pipe and at C the level is 1 m above the pipe.

Assume the Fanning friction factor, f = 0.006 and the entrance and exit losses are 0.5(u2/2g) and 1.0(u2/2g) respectively. The loss due to each of the 90° bends is 0.4(u2/2g).

Calculate:

a) The quantity which will flow through the pipe

b) The pressure at point B, commenting on its implications

c) The total flow rate needs to be increased by 18 m3/hour by adding a second pipe, with similar entrance, exit and bends, in parallel to the first. What should be the diameter of this second pipe? 

Figure Q1 5 m 25 m B 15 m 5 m 1 m C