Page 75 - Know and Understand Centrifugal Pumps

Know and Understand Centrifugal Pumps

Turbine pumps

This group is characterized as having bearings lubricated with the
pumped liquid. These pumps are popular in multi-stage construction.
The impellers discharge into a vertical support column housing the
rotating shaft. These pumps are often installed into deep well water
applications. The impellers are commonly mixed flow types, where one
stage feeds the next stage through a bell shaped vertical diffuser.

Specific duty pumps

Along with the previously described mechanical configurations, there
are some unique types of pumps classified by some special function.
Examples are:
Wastewater pumps have anti-clog impellers to handle large irregular
solids.
Abrasive pumps are made of hardened metal or even rubber-lined to
handle abrasive particles in high quantities with minimal erosion.

Hot water re-circulation pumps are small fractional horsepower
models used to heat homes and buildings with circulated hot water
through radiators.
Canned motor pumps are hermetically sealed to prevent emissions,
leakage and motor damage. They require no conventional
mechanical seal.

The typical ANSI pump
- ~ ~ _ ~ _
This type of end suction vertically split pump is used extensively in the
chemical process industry. It is probably the most popular of all pump
designs, see Figure 6-8.
ANSI is an acronym meaning American National Standards Institute. It
was previously known as AVS or American Voluntary Standards.
This pump is most popular in the chemical process industry.
w It can handle abrasive and corrosive liquids.
w It is a one stage, end suction, back-pullout design pump. There is
more information on this pump in Chapter 7 about pump curves.
w This pump is available in a wide variety of materials.
Numerous optional impellers are available.

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