Hydraulic Rams
A hydraulic ram is the large output piston of a hydraulic cylinder, performing as a water-powered pump. In a hydraulic cylinder containing a hydraulic ram, the ram measures more than half the width of the piston rod. Hydraulic rams are used primarily to push and are generally reserved for high-pressure applications.
The simple construction of hydraulic rams lends to its attributes of being easy and inexpensive to build and maintain. A hydraulic ram has only two moving parts, including a spring or weight-loaded valve (for waste) and a delivery check valve. Hydraulic rams are very reliable, although they do run the risk of freezing in cold temperatures.
Hydraulic rams are popular in rural areas, since they require no outside power source besides water. In hydraulic ram pumps, water provides all the kinetic energy needed for the pump to work. The pump uses the momentum of a large amount of moving water to pump a considerably smaller amount of water uphill. The disadvantage to the system is that it wastes a large amount of water in comparison to the amount that actually travels through the pipe.