372 



ENGINEERING ON THE FARM 



water flows down a drive pipe, A, flowing out of the valve, F, 

 until the friction of the passing water closes this valve. 

 Then the oncoming column of water. A, pushing into the 

 airchamber, C, compresses the air, passes out the service 

 pipe, D, until the force of the water in A is balanced by the 

 weight of water in D. E will now close of its own weight. 

 F, likewise, will open, and the water in A will again start 

 to flow and the process is repeated. This gives an irregular 



VSV/7 



After University of Minnesota 



Fig. 290. Principle and method of installing a hydraulic ram 



flow, but is very reliable and not expensive. A 5 -foot head 

 will raise water 40 feet provided pipe A is 30 or 40 feet 

 long. Only about one-seventh of the available water can 

 be raised, but the ram will work night and day. One fea- 

 ture not to be overlooked in the installation of the ram is 

 the provision for a spillway for the six-sevenths of the 

 water supply which has been through the ram. If this is 

 not provided, the ram will be submerged and cease to operate. 

 A ram will cost from $11 to $24. Pipe and supply tanks 

 are the large items. 



Piping. All pipes offer a resistance to the flow of water 

 through the pipes. This is influenced most largely by the 

 diameter, length of the pipe, and the quantity of water to 

 be forced through. It will be noted from the table at the 

 top of page 273 that with the low head or pressure it will be 

 necessary to use one-inch pipes in most cases. 



