CHAPTER 2
BOILER MAINTENANCE
Learning Objective: Recognize maintenance requirements and procedures for
boilers and auxiliary equipment; recognize boiler operation steps and checks and
safety requirements.
As a Utilitiesman, it is your responsibility to operate,
maintain, and repair boilers. You can perform operator
maintenance on shore-based boilers; perform preventive
maintenance and minor repairs on boilers and associated
equipment; complete chemical tests on boiler water and
feedwater; replace defective boiler tubes; test, adjust, and
recalibrate boiler gauges and other accessories.
This chapter provides information on some of the
methods, procedures, and techniques used to operate,
maintain, and repair boilers and associated equipment
safely under typical conditions. Because of the broad
scope of tasks involved in operating and servicing
boilers, this chapter does not tell you all you need to
know about the subject. Learning how to accomplish
the procedures given in the following sections can help
you acquire a basis on which to develop more
advanced skills. While the procedures given in this
chapter are typical, you should always follow the
manufacturer’s instructions for the equipment.
MAINTENANCE OF AUXILIARY
EQUIPMENT
Learning Objective: Recognize and
auxiliary equipment maintenance.
understand basic
A well-planned maintenance program is the key to
avoid unnecessary downtime or costly repairs,
promotes safety, and aids local inspection. An
inspection schedule listing the procedures should be
established. It is recommended that a boiler room log
or record be maintained for recording the daily,
weekly, monthly, and yearly maintenance activities.
This provides a valuable guide and aids in the
operational efficiency, length of service, and safe
operation of a boiler. It is also important to remember
that improperly performed maintenance is just as
damaging to a boiler as no maintenance at all.
MAINTENANCE REQUIREMENTS FOR
CONTROL OF WATER LEVEL
The need to check water level controls and the
water side of the pressure vessel periodically cannot be
overemphasized. Most instances of major boiler
damage are the result of operating with low water or
using untreated (or incorrectly) treated water. Always
be sure of the boiler water level and blow down the
water column routinely. Check samples of boiler water
and condensate according to procedures recom-
mended by your water consultant (figs. 2-1 and 2-2).
Since the manufacturer generally sets low water
cutoff devices, no attempt should be made to alter or
adjust these controls. If a low water device should
become erratic in operation or if the setting changes
from previously established levels, check for reasons
and correct it by repair or replacement.
Figure 2-3 is a replica of the low water cutoff plate
attached to a steam boiler. These instructions should be
followed on a definite schedule. These controls
normally function for long periods of time and may
lead to laxity in testing on the assumption that normal
operation will continue indefinitely.
On a steam boiler, the head mechanism of the low
water cutoff devices should be removed from the bowl
at least once a month to check and clean the float ball,
the internal moving parts, and the bowl or water
column. Remove the pipe plugs from the tees or
crosses and make certain the cross-connecting piping
is clean and free of obstructions. Controls must be
mounted in a plumb position for proper performance.
A scheduled blowdown of the water controls on a
steam boiler should be maintained. It is impractical to
blow down the low water cutoff devices on a hot-water
boiler since the entire water content of the system
would be involved. Many hot-water systems are fully
closed and any loss of water would require makeup and
2-1
