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Centrifugal Pump Basics

Brake Horsepower Exercise

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Centrifugal Pump Basics

Minimum Continuous Stable Flow

• Mainly due to pump design and

suction conditions, higher minimum

flows are required to avoid unstableflow which is internal recirculation of

the liquid between the impeller and

the casing.

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Series Operation Facts

Centrifugal Pump Basics

•When a pump’s discharge becomes suction of the next pump

•Will produce more head but the flow rate will remain constant

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Centrifugal Pump Basics

Parallel Operation Facts

•When two or more pumps are operated in the same discharge column,

the head remain constant but the flow rate will increase

•Can be found in applications where flow rate is critical

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Q&A

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Centrifugal Pump Basics

Cavitation

•If the pressure energy falls below the vapor pressure of a liquid, then

vapor is formed.

•Increase in volume from liquid to vapor depends on the liquid,

temperature, and vapor pressure.

1 ft³ of water, evaporated at 212°F and 14.696 psia, becomes

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1606 ft³ of dry saturated steam, (vapor).*

•Vapor bubbles on their way through the pump re-condense or collapse

when they reach regions of higher pressure

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