Pump

Learn About Pumps
Click a topic below to learn about:
1. Main characteristics to be considered
2. Impeller Diameter and RPM
3. Pump Characteristic Performance curve
4. Brake Horsepower
5. Cavitation
6. Time, Temperature and Pressure effects
1. Main characteristics to be considered
There are two main characteristics to be considered when determining the correct pump:
1. The right type of pump for the application and liquid.
2. The pump performance or characteristic requirements.
First, in order to select the right type of pump you need to know the fundamentals. Pumps can be broken into two major categories. The first category is the positive displacement (PD) pump in which the liquid is moved by physically displacing that liquid from a confined space. Positive displacement pumps come in several configurations such as vane, gear, screw, progressive cavity, Archimedes' screw, piston, plunger, and others. Some of the very first pumps used by man for primitive irrigation were positive displacement pumps. PumpU will discuss PD pumps second.
The next major category is the centrifugal pump. The centrifugal pump adds energy to the liquid by first increasing the velocity of the liquid (adding kinetic energy) and then converting the kinetic energy to potential energy by directing the liquid into a progressively increasing volume, which in turn slows the velocity. Centrifugal pumps come in several configurations such as axial flow or propeller pumps, mixed flow or turbine pumps, and Francis vane and radial vane pumps. The last two categories represent the type of pumps dealt with most.
A centrifugal pump is a device, which converts driver energy to kinetic energy in a liquid by accelerating it to the outer rim of a revolving device known as an impeller. The impeller, driven by the pump shaft adds the velocity component to the liquid by centrifugally casting the liquid away from the impeller vane tips. The key idea here is that the energy created is kinetic...