CHAPTER LXXVI 

 DISTRIBUTING AND STORING WATER 



Water Pipe. After a consideration of the source of sup- 

 ply for a farm water system, the quantity of water required, 

 and the pumping plant, the next thing to be considered is the 

 distributing system or piping by which the water is conveyed 

 to points where needed and to the reservoir for storage. For 

 farm water systems, wrought-iron or steel pipe with screwed 

 joints is universally used. Cast-iron pipe with leaded joints 

 is used for pipes four inches or larger in diameter, but pipes 

 this large are seldom required in connection with farm sys- 

 tems. Wrought-iron or steel pipes placed underground 

 should always be galvanized or coated with asphalt to pro- 

 tect them from rust. They are commonly galvanized. 



Sizes of Pipe. The two sizes of pipe in general use are 

 three-fourths and one inch. In rare instances half-inch pipe 

 may be used, but the flow of water through this size pipe is 

 very slow, especially if a long length is used. The friction 

 between the water and the walls of the pipe counteracts the 

 pressure which causes the water to flow. The following 

 table, taken from the Cyclopedia of American Agriculture, 

 indicates how great the friction is with small pipe. 



Referring to the table it is seen that if a pump is deliv- 

 ering four gallons per minute through a length of J^-inch pipe 

 500 feet long, it must do so against a friction head or pressure 

 of 270 feet of water. This would be impractical. Although 

 the table does not include %-inch pipe, the loss of pressure 

 due to friction would lie between the values given for Y^- and 

 1-inch pipe. The average farm pump will discharge about 



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