1.2 CHAPTER ONE
INTRODUCTION______________________________________________________
Only the sail can contend with the pump for the title of the earliest invention for the con-
version of natural energy to useful work, and it is doubtful that the sail takes precedence.
Because the sail cannot, in any event, be classified as a machine, the pump stands essen-
tially unchallenged as the earliest form of machine for substituting natural energy for
human physical effort.
The earliest pumps we know of are variously known, depending on which culture
recorded their description, as Persian wheels, waterwheels, or norias. These devices were
all undershot waterwheels containing buckets that filled with water when they were sub-
merged in a stream and that automatically emptied into a collecting trough as they were
carried to their highest point by the rotating wheel. Similar waterwheels have continued
in existence in parts of the Orient even into the twentieth century.
The best-known of the early pumps, the Archimedean screw, also persists into modern
times. It is still being manufactured for low-head applications where the liquid is fre-
quently laden with trash or other solids.
Perhaps most interesting, however, is the fact that with all the technological develop-
ment that has occurred since ancient times, including the transformation from water
power through other forms of energy all the way to nuclear fission, the pump remains
probably the second most common machine in use, exceeded in numbers only by the elec-
tric motor.
Because pumps have existed for so long and are so widely used, it is hardly surprising
that they are produced in a seemingly endless variety of sizes and types and are applied
to an apparently equally endless variety of services.Although this variety has contributed
to an extensive body of periodical literature, it has also tended to preclude the publication
of comprehensive works. With the preparation of this handbook, an effort has been made
to create just such a comprehensive source.
Even here, however, it has been necessary to impose a limitation on subject matter.
It has been necessary to exclude material uniquely pertinent to certain types of auxil-
iary pumps that lose their identity to the basic machine they serve and where the user
controls neither the specification, purchase, nor operation of the pump. Examples of
such pumps would be those incorporated into automobiles or domestic appliances. Nev-
ertheless, these pumps do fall within classifications and types covered in the handbook,
and basic information on them may therefore be obtained herein after the type of pump
has been identified. Only specific details of these highly proprietary applications are
omitted.
Such extensive coverage has required the establishment of a systematic method of
classifying pumps. Although some rare types may have been overlooked in spite of all pre-
cautions, and obsolete types that are no longer of practical importance have been deliber-
ately omitted, principal classifications and subordinate types are covered in the following
section.
CLASSIFICATION OF PUMPS___________________________________________
Pumps may be classified on the basis of the applications they serve, the materials from
which they are constructed, the liquids they handle, and even their orientation in space.
All such classifications, however, are limited in scope and tend to substantially overlap
each other. A more basic system of classification, the one used in this handbook, first
defines the principle by which energy is added to the fluid, goes on to identify the means
by which this principle is implemented, and finally delineates specific geometries com-
monly employed. This system is therefore related to the pump itself and is unrelated to
any consideration external to the pump or even to the materials from which it may be
constructed.
Under this system, all pumps may be divided into two major categories: (1) dynamic,
in which energy is continuously added to increase the fluid velocities within the machine