CHAPTER V 



WATER CONDUCTORS AND ACCESSORIES 

 1. WATER CONDUCTORS 



Classification of Water Conductors. As in the case of dams, 

 there is a great variety of types of water conductors, the par- 

 ticular kind to be used being entirely governed by the nature of 

 the development as well as by economy. Where the power-house 

 is located near the dam, there may be no neeol for conduits at all, as 

 in low-head plants, or they may simply consist of very short pipes. 

 For medium- and high-head developments, however, a more 

 elaborate system of conduits must as a rule be provided, as the 

 water must in many such instances be diverted for miles, before 

 it finally reaches the power-house. 



The different kinds of water conductors in general use may be 

 divided into two classes, open or closed, the closed construction 

 being either of the low- or high-pressure type. 



CLASSIFICATION OF WATER CONDUCTORS 

 Open. 



Canals: lined or unlined. 

 Flumes : wood, concrete or steel. 

 Closed. 



Low-pressure. 

 Tunnels. 



Pipe : wood, concrete or steel. 

 High-pressure . 

 Pipe: steel. 



Open canals and flumes are often used for carrying the water 

 from the point of diversion to the beginning of the pressure lines. 

 This method was extensively used in earlier developments, and 

 while it may in many cases be the cheapest, a higher efficiency can 

 be obtained by a closed system of tunnels and pipes, in that the 

 total head will be greater. Where the contour of the country is 

 very irregular the cost of excavating for canals and of building 

 high trestles for the flumes may be very high, and in such instances 



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