Excessive torque, side thrust, and friction make crank-driven pumps cumbersome and expensive at high pressures. But in hydraulically driven pumps, these effects are eliminated or minimized and higher pressures can be attained. Also, longer strokes are characteristic; therefore, rates of stress buildup are reduced in such areas as check valves and packings, which result in less maintenance and longer life. Without rotational inertia, controllability is increased which in turn increase safety.
Essentially continuous flow and high efficiencies can be obtained with a combination of double acting pumps.
Development of the hydraulic drive for high-pressure piston pumps has been a key factor in attaining high pressures now found in commercially feasible systems. Compared to other forms of reciprocating pumps widely used at lower pressures, this pump has received little attention in the technical literature. It’s often called an “intensifier” and not only handles large differences between intake and discharge pressures but makes easier certain design problems which are multiplied at high pressures.
This hydraulically driven pump is useful at pressures as low as 5,000 lb per square inch and up to 200,000 lb. It has high efficiency and, considering its large capacity, it’s physically small. The pump is easily adaptable and its controllability simplifies the problems of safety and maintenance. It pumps both liquid and gases and, because of its flexibility, it’s constantly being adapted to new applications in chemical and physical processing.