Keep engine air intake filters clean to maintain
sufficient induction of air.
Q1. An electric motor is what part of a pump?
Q2. Excessive rubbing or wear is a result of what
condition caused by improper belt tension?
Q3. Before starting a diesel engine, you must
complete what type of inspection?
Q4. Whatfeature is the difference between agasoline
and a diesel engine?
LEARNING OBJECTIVE: Identify specific
types of pumps and the operation and
maintenance procedures for each; identify
methods used for installing piping, valves, and
the maintenance of stuffing box, packing, and
mechanical seals in pumps; and identify the
methods used for the maintenance of internal
A Utilitiesman is required to work with pumps of
many shapes and size. Some of the primary uses of
pumps are as follows:
To supply feedwater to boilers
To deliver fuel oil to oil-fired boilers
To circulate coolants and lubricants in internal
To supply chemical feed in water purification
To lift water from cells and distribute it
throughout a system
To discharge sewage into setting tanks or
The principles of pump operation, the principle
of suction force, the types of valves used in pump
operation, the different types of pumps, pump
installation, and safety precautions that a Utilitiesman
has to know to operate and maintain the various types
of pumps used today are discussed in this section.
Pumps are used to move any substance that flows
or can be made to flow. Most commonly, pumps are
used to move water, oil, and other liquids; however,
steam and other gases are also fluid and can be moved
with pumps, as can molten metal, sludge, and mud.
A pump is a device that uses an external source of
power to force fluid to move from one place to another.
A pump develops no energy of its own; it merely
transforms energy from the external source (steam
turbine, electric motor) into mechanical kinetic
energy, which is manifested by the motion of the fluid.
This kinetic energy is then used to do work. For
example. to raise liquid from one level to another, as
when water is raised from a well. Other examples are to
transport liquid through a pipe, as when oil is moved
through an oil pipeline; to move liquid against some
resistance, as when water is pumped to a boiler under
pressure; or to force liquid through a hydraulic system,
against resistance. Every pump has a POWER END,
whether it is a steam turbine, a reciprocating steam
engine, a steam jet. or some type of electric motor.
Each pump also has a FLUID END, where the fluid
enters (suction) and leaves (discharges) the pump.
The addition of energy to a liquid by a pump
usually. results in an increase in pressure, which is
generally referred to as HEAD. In pump operation,
you should know that there are four types of head-net
positive suction head, suction head, discharge head,
and total discharge head. The definition of each of the
types of head is as follows:
The NET POSITIVE SUCTION HEAD
(NPSH) is the suction pressure minus the vapor
pressure expressed in feet of liquid at the pump
suction. This type of head pressure is commonly
referred to as NPSH.
The SUCTION HEAD on a pump means the
total pressure of the liquid entering the pump. In
a de-aerating feed tank operating under saturated
conditions. the suction head of the feed booster
pump equals the NPSH plus the auxiliary
The DISCHARGE HEAD means the pressureof
liquid leaving the pump or the level of liquid
with respect to the level of the pump on the
The TOTAL DISCHARGE HEAD is the net
difference between the suction head and the
NOTE: When positive, suction head is usually
expressed in feet of water. When negative, it is
expressed in inches of mercury.
When a pump operates below the level of a liquid,
its suction end receives the liquid under a gravity flow.
When the pump is located above the level of the liquid
being pumped, the pump establishes a vacuum at the