PIPE LINE LOSSES 251) 



there are six right-angled bends having a radius of curvature of 6 inches, 

 it is suddenly contracted to 3 inches diameter, and remains of this dia- 

 meter for 2 miles, until its exit directly into the side of a second reservoir 

 at a point 2 feet below the surface. The difference of surface level in the 

 two reservoirs is 220 feet. Determine the flow through the pipe per 

 minrte. 



Taking the losses in the order in which they occur we have 



o 



(1) Loss at entrance = *5 Hi (in eddy formation) where Vi = velocity 



2 (i 



in 6-inch pipe. 



(2) Frictional losses in one mile of 6-inch pipe. Taking 



/ = -010 this becomes i '010X280 





o 



= 422-4 I* feet. 



(3) Loss at six bends in 6-inch pipe. 



= 6 r* 36 i ^ feet (P- 255 ) 



L J ^ g 



= 2-16 |^- feet. 



(4) Loss at sudden change of section. 



Assuming a vena contracta to be formed of sectional area equal to *66 

 that of the 3-inch pipe, we have, if v 2 be the velocity in this pipe. 



i- 2 2 (1 , ) 2 '266 v. 



Since = = 4, we have loss at change of section = 4-25 ^- feet 

 t?i o "2 g 



(5) Friction loss in 3-inch pipe. 



/ I r a a 16 f I v? 

 This equals l 



'2 g m 2 g m 



16 X -01 X 2 x 5,280 ri 







= 27,033-6^- feet. 

 ^ 9 



(6) Loss at exit. 



Since the whole of the kinetic energy is thrown away, the loss will be 



