244 



HYDRAULICS AND ITS APPLICATIONS 



C I 

 for flow in clean C. I. pipes: h ,-,- ^ , where C has the following 



values : 



- Compare these with the values obtained by using Unwin's formula 

 and determine the per cent, difference for a 3 inch and 6 inch pipe ai 

 velocities of 2, 4, 6, and 10 feet per second. 

 Answer. 



(5) The jet of a Pelton wheel has an effective diameter of 2 inches 

 The supply pipe is 6,000 feet long and is an asphalted pipe 15 inche 

 diameter, and the supply head is 800 feet. Determine the probabl 

 discharge in cubic feet per second, and the horse-power of the jet 

 Assume c v = '972 : f = '0050. 



Answer. Velocity of jet = 218 f.s. ; discharge = 4'75 

 cubic feet per second ; 396 horse-power. 



(6) With a given slope, a clean cast-iron pipe 9 inches diameter, i 

 found to give a discharge of 25,000 gallons per hour. Determine th 

 necessary diameter of pipe, having twice the slope, to give a discharge c 

 50,000 gallons per hour. (Take Unwin's values for the index of d an 

 of v, p. 202.) 



Answer. 10'3 inches. 



(7) The outlet valve from a main 5,000 feet long is closed in 1 seconc 

 Determine the rise in pressure if the initial velocity of flow is 4 fee 

 per second, and the pipe is rigid. 



Answer. 254*8 Ibs. square inch. 



