Centrifugal Pump Characteristic

It is important to note that at any fixed speed the pump well operate along this certain curve and no other point for instance on the curve below. On pump with variable speed driver such as steam turbine, it is possible to change the characteristic curve. It is important to remember that the head produced will be the same for any clean liquid of the same viscosity. The pressure rise, however, will in proportion to the specific gravity. Viscosities of less than 50 kPa's (50 cP) do not affect the head materially.

Single Stage Centrifugal Pump
This pump are available to capacities up to and over 1.136 x 104 m3/h (50,000 gal/min) for heads (pressures) up to 488 m (1600 ft). They are available in a variety of design for particular services.

Process Pumps
This term is usually applied to single stage pedestal mounted units with single suction overhung impellers and with a single packing bos. These pumps are ruggedly designed for ease in arrangements, and are built especially to handle corrosive or other wise difficult to handle liquids.

Specially but not exclusively for the chemical industry, most pump manufactures now build to national standards horizontal and vertical process pumps. American National Standards Institute (ANSI) Standard B73 1 - 1977 and B73 2 - 1975 apply to be horizontal and vertical in line pumps respectively.

The horizontal pumps are available in line pumps for capacities up to 900 m3/h (4000 gal/min), the vertical in line pumps, for capacities up to 320 m3/h (1400 gal/min). Both horizontal and vertical in lime pumps are available for heads up to 120 m (400 ft). The intent of each ANSI specification in that pumps from all vendors for a given nominal capacity and total dynamic head at a given rotative speed shall be dimensionally interchangeable with respect to mounting, size, and location of suction and discharge nozzles, input shaft, base plate, and foundation bolts.