A high pressure pump is broadly defined as any pump that can generate high discharge pressure, generally in excess of 800 psi. that generate pressures between 800 and 3000 psi are known as moderate pressure pumps, while pumps that generate anywhere between 3000 psi and 5000 psi are known as very high pressure pumps. Apart from these pressure levels, there is another category of pressure pumps known as ultra pressure pumps that generate pressures significantly in excess of 5000 psi.
Common types of pump used for applications are reciprocating positive displacement pumps, particularly plunger pumps, which are capable of handling applications easily. Though in many cases pistons are also used with pumps, they are usually used only for applications that require working pressures below 1000 psi. One common type of positive displacement pump used for applications is the triplex plunger pump that consist of three plungers driven by a single prime mover. The parallel use of three plungers gives the triplex pump a discharge for every 120 degrees rotation of the prime mover. Another similar type of reciprocating pump that performs pressure pumping duties is the quintuplex plunger pump, which is, as the name suggests with four plungers driven by a single prime mover. Quintuplex plunger pumps and triplex pumps are commonly known as power pumps and generally found in pressure applications.
A device that has found widespread adoption in high pressure applications is the hydraulically driven intensifier or amplifier. These devices use hydraulic pressure to significantly increase the pressure of the fluid being pumped. The intensifier consists of a common rod connecting two pistons with different bore sizes. When hydraulic fluid acts on the larger piston, it causes the smaller piston to be moved. Depending on the direction in which the smaller piston is moved by the hydraulic piston, it either takes suction or pressurizes and discharges the working fluid at very high pressure. There are two types of intensifiers and based on their construction and working, they are termed single shot intensifiers and reciprocating intensifiers. A single shot intensifier consists of one large hydraulic actuator piston and a single, smaller, pressure piston - both connected by a common piston rod. When the large piston is moved, it makes the smaller piston move and fluid discharge takes place. When the larger piston is returned to its original position, by a spring or air-retraction, the smaller piston moves back, taking in the suction.