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Pump Selection and Purchasing

9 At what speed was it running?
9 What materials of construction were used?
9 What type of mechanical seal was used?
9 What types of auxiliary systems were used?
9 What kind of operational/maintenance record was experienced?

Once this type of information has been established the selection of the
pump can proceed with the type of unit required and then the best
hydraulic fit for the system.

5.1.2 End user data sheets
Many industries provide their suppliers with standardized data sheets
which have evolved over the years. While a well designed data sheet will
provide much of the information reviewed above, they generally do not
supply any system information or previous operational experience, both
of which are vital for an optimum pump selection. It is strongly
recommended that the system designer and equipment supplier
cooperate as much as possible to ensure that the best possible selection
ensues.

One of the most widely used data sheets is the Centrifugal Pump Data
Sheet incorporated in the API Standard 610 for Centrifugal Pumps for
General Refinery Service that is published by the American Petroleum
Institute. This is also available in SI units, and both sheets are provided
here for the benefit of the reader. Many companies have modified this
data sheet to suit their own specific requirements.

5.2 System operating considerations

An essential part of the 'Operational Experience' is a detailed
lmowledge of the system in which the pump will operate.

.2.1 Closed loop systems
When a pump is required to perform in a closed loop where the pump
discharges through the system and back to it's own suction nozzle, the
static head is effectively zero and the system characteristics will remain
fairly constant. Consequently, the system curve will experience little
movement, and the pump selection needs only to generate a pump
performance curve that intersects with the system curve at the required
Design Point. With such a stable operation, there will be little
movement of either the pump curve or the system curve, and the
operating point will remain at the Design Flow throughout the life of

73 m
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