“Hydraulics” is the field of study related to the mechanical properties of liquid. Pumps that are said to be hydraulic are so named because of they take advantage of the mechanical properties of liquid in order to achieve work; all hydraulic pumps have that quality in common.
There are many different kinds of hydraulic pumps, and there are two main categories into which all hydraulic pumps can be divided. The first category involves hydraulic pumps that operate independent of auxiliary power sources like gas and electric motors. These hydraulic pump varieties can make use of a liquid’s kinetic energy in order to move it from one place to another.
These pumps are usually called ram pumps, but they also sometimes go by other names; hydraulic hand pumps, for example, are never referred to as ram pumps, though both machines’ principle of operation is similar. Ram pumps are increasingly popular in the developing world because they can be used, without the use of fuel or electricity, to pump water from rivers, streams or other sources to places where it is needed.
Because fuel and electricity can be scarce or expensive in many parts of the developing world, ram pumps are a very attractive water pumping solution. The other main category involves hydraulic pumps that make use of auxiliary power sources. These pumps are often used for the transmission of hydraulic fluids in machinery as well as in some other uses, such as in pressure washers.
The first category of hydraulic pumps harnesses natural forces and the kinetic energy of the fluids involved in pumping. In a ram pump for example, an inlet pipe on slight decline directs water away from its source and into the pump reservoir. As the water flows into the reservoir, the force of gravity and the water’s kinetic energy cause pressure to build up. When sufficient pressure is built, a valve above the reservoir opens, which allows for the pressurized water to flow out into a pressure chamber.
The water in this chamber becomes further pressurized, which eventually forces it out of the chamber and into a tube that ultimately directs the water to its final destination. Relief valves and pressurized air are also involved in this process in order to avoid bursting pipes or ruptures in the pumps’ reservoirs. The second category involves drawing hydraulic fluids like oil out of a reservoir and into a hydraulic system. This process usually involves cylinders and a series of tubes through which the fluid travels and is subject to varying levels of pressure.