HYDRAULIC RAM 



688 



1,500 gallons capacity, the capacity of such a plant ranges up to about 

 750,000 gallons per day of twelve hours. 



ART. 186. THE HYDRAULIC RAM. 



The hydraulic ram, which owes its conception as a practical machine 

 to Montgolfier (about the end of the eighteenth century), is an apparatus 

 devised to utilize the kinetic energy of a moving column of water to 

 pump up part of this water to a height greater than that of the supply 

 head. In its simplest form, the ram consists of an inclined supply pipe 



FIG. 330. Types of Hydraulic Ram. 



S (Fig. 330 a), terminating in a valve box B. This valve box is fitted 

 with a waste valve V\ t opening inwards, and a discharge valve F 2 opening 

 outwards and delivering pressure water into an air vessel A, from which 

 it is delivered in a steady stream by the discharge pipe P. 



The action of the ram is as follows : The waste valve being opened, 

 water is free to escape, and flow is set up along the supply pipe. The 

 velocity of flow increases under the influence of the supply head until the 

 dynamic pressure on the under side of the valve becomes sufficiently great 

 to overcome its weight. The valve now closes rapidly and the supply 

 column suffers a consequent retardation which gives rise to a rapid 

 increase of pressure in the valve box until this pressure becomes 

 sufficiently great to open the delivery valve. 



