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Metering Pumps
Published in Béla G. Lipták, Flow Measurement, 2020
The piston pump employs a piston or plunger which moves with a reciprocating motion within a chamber. A fixed volume of liquid is delivered with each stroke. The flow rate is a function of piston diameter, chamber length, and piston speed. Check valves located at the pump inlet and outlet are required to prevent backflow. A schematic of a typical piston pump is shown in Figure 13c. The piston produces pressure in only one direction; therefore, the flow produced by plunger pumps (as piston pumps are sometimes called) is pulsating. If the pulsating flow characteristics are undesirable, a dampening reservoir (accumulator) should be installed in the discharge line of the pump. Another method available to reduce pulsation is to use a pump that employs more than one chamber/piston combination in parallel. Pumps having as many as four chambers (cylinders) are commercially available. These multiple-piston pumps are called duplex pumps if they have two pistons; triplex, if they have three; etc. (Figure 13d).
Hydraulic Machines
Published in Frank R. Spellman, Handbook of Water and Wastewater Treatment Plant Operations, 2020
In 287 BCE, Archimedes (Greek mathematician and physicist) invented the screw pump (see Figure 7.1). The Roman emperor, Nero, around AD 100, is often credited for the development of the piston pump. In operation, the piston pump displaces volume after volume of water with each stroke. The piston pump has two basic problems: (1) its size limits its capacity and (2) it is a high consumer of energy. It was not until the 19th century before pumping technology took a leap forward from its rudimentary beginnings. The first fully functional centrifugal pumps were developed in the 1800s. Centrifugal pumps can move great quantities of water with much smaller units than the pumps previously in use.
Hydraulic Power Generation
Published in Qin Zhang, Basics of Hydraulic Systems, 2019
Producing pressurized flow by forcing the fluid out of the cylinder using a well-sealed piston, a piston pump can generate very high pressure by pushing the fluid against heavy loads with high volumetric efficiency. It is reasonable to expect a piston pump to have a volumetric efficiency of over 97% and an overall efficiency of 90% or higher. Because of this feature, piston pumps are often used in heavy-duty applications with high operating pressures. It should also be noted that the high efficiency and high operating pressure are normally accompanied with high cost.
Augmented reality applied to design for disassembly assessment for a volumetric pump with rotating cylinder
Published in Production & Manufacturing Research, 2023
Leonardo Frizziero, Christian Leon-Cardenas, Marco Freddi, Alessandro Grassoni, Alfredo Liverani
Piston pumps are the best choice for high-pressure applications or those requiring great performances. They belong to the class of variable displacement pumps and offer a long service life and great efficiency. Radial piston pumps (Figure 4) are very robust radial devices with high volumetric efficiency, wide speed range and high reliability, even in severe conditions. The pump studied has a closed pump body, an intake line and a delivery line, is equipped with a hollow piston, with a spring inside that moves it, and radial to a shaft in which it is inserted. RN 3 × 11.8 type roller bearings are inserted between an inner and outer ring. The two side shims act as containment. Given the simplicity of the device and the small size, there are no bearings between the shaft and the body: for heavier tasks, the use of bushings or rolling bearings would be appropriate.
Numerical and experimental study on the churning losses of 2D high-speed piston pumps
Published in Engineering Applications of Computational Fluid Mechanics, 2020
Yu Huang, Chuan Ding, Heyuan Wang, Jian Ruan
Axial piston pumps that belong to hydraulic components are widely used in engineering, agriculture, and aerospace fields for many advantages, including their high power/weight ratio, strong load capacity, and high efficiency (Alle et al., 2016; Hongchuan et al., 2015; Ye et al., 2019). However, with the increase in the rotational speed, the energy losses of axial piston pumps significantly increase, so their efficiency is decreased (Manring, 1996; McCandlish & Dorey, 1984). The energy losses can be normally divided into three groups: mechanical losses, volumetric losses, and churning losses (Manring, 1998, 1999; He-sheng et al., 2014; Tang et al., 2016; Zhang et al., 2017).