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Maintenance
Requirements
General
Maintenance
A
well-planned maintenance program
avoids unnecessary down time or
costly repairs. It also promotes
safety and aids boiler code and
local inspectors. An inspection
schedule listing the procedures
should be established. It is
recommended that boiler room log
or record be maintained,
recording daily, weekly,
monthly, and yearly maintenance
activities. This provides a
valuable guide and aids in
obtaining boiler availability
factor to determine shutdown
frequency, economies, length of
service, etc.
Even
though the boiler has electrical
and mechanical devices that make
it automatic or semi-automatic
in operation, these devices
require systematic and periodic
maintenance. Any
"automatic" features
do not relieve the operator from
responsibility, but rather free
him from certain repetitive
chores, providing him with time
to devote to upkeep and
maintenance.
Good
housekeeping helps to maintain a
professional boiler room
appearance. Only trained and
authorized personnel should be
permitted to operate, adjust, or
repair the boiler and its
related equipment. The boiler
room should be kept free of all
material and equipment not
necessary for operation for the
boiler.
Alertness
in recognizing unusual noises,
improper gauge readings, leaks,
signs of overheating, etc., can
make the operator aware of
developing malfunction and
initiate prompt corrective
action that may prevent
excessive repairs or unexpected
down time. All piping
connections to the system and
its accessories must be
maintained leak-proof because
even a minor leak, if neglected,
may soon become serious. This
applies especially to the water
gauge glass, water level
control, piping, valve packing,
and manway gaskets. If serious
leaks occur shut down the boiler
immediately and gradually reduce
steam pressure. Do not attempt
to make repairs while the boiler
is under pressure.
Shift
Maintenance
Shift
maintenance should include
checking the boiler water level
in the gauge glass and the
boiler steam pressure on the
gauge. Operate the intermittent
blowdown valve to remove any
accumulated solids in the mud
drum. The valves on the water
column and gauge glass should be
operated to make sure these
connections are clear. Monitor
water chemistry to adjust the
chemical feed treatment and
continuous blowdown as required,
to remain within water treatment
guidelines established by the
Owner's water treatment
consultant.
Daily
Maintenance
Daily
Maintenance should include a
check of the burner operation,
including fuel pressure,
atomizing air or steam pressure,
visual appearance, etc. Clean
the observation ports during
periods of low fire or shutdown.
Test the boiler level alarms and
low water cutoff. Maintain a
daily schedule of sootblowing.
Monthly
Maintenance
Check
the condition of the refractory
for significant damage or
cracking. Patch and repair the
refractory as required. Frequent
wash coating of refractory
surfaces is recommended. Use
high temperature bonding,
air-dry type mortar diluted with
water, to the consistency of
light cream, for this purpose.
This will seal small cracks and
prolong the life of the
refractory. Any large cracks
should be cleaned out and filled
with mortar.
Follow
the recommendations of you
authorized inspector pertaining
to safety valve inspection and
testing. The frequency of
testing, either by the use of
the lifting lever or by raising
the steam pressure, should be
based on the recommendation of
your authorized inspector. Test
the boiler safety valves in
accordance with the
manufacturer's instructions to
be absolutely sure that the
valves have not corroded shut. Failure
of the relief valves in an
overpressure situation is DISASTROUS!
Annual
Maintenance
Have
the unit inspected and checked
by a service representative from
the manufacturer, if possible.
Clean
both the heating and heated
sides of the boiler. Remove all
manway and handhole covers. Open
all bottom blowdown and drain
valves. Hose the inside of the
boiler with clean water under
high pressure. Use a hand
scraper to remove accumulated
sludge and scale. Start near the
top and work toward the bottom.
After cleaning tube exteriors,
inspect the tube surfaces for
signs of overheating, such as
bulging, blackened surfaces in
the tubes, etc.
Specific
local conditions determine the
use of "wet" or
"dry" storage during
shutdown periods. If you are
unsure of which procedure to
follow, contact the Owner's
water treatment consultant or
your local insurance company.
Replacement
of flange, manway, and handhole
gaskets
1.
Clean metal surfaces where cover
plate bears against shell plate
or ring.
2.
Always use new gaskets. Apply
graphite paste to gasket to
prevent sticking and assure
tightness.
3.
Use care in centering cover
plate and gasket in shell
opening. Draw bolts up firmly.
Yokes are designed for the
positioning and holding of the
covers only. Gasket sealing is
accomplished by the application
of internal pressure.
4.
Spare gaskets should be
maintained in your inventory to
minimize your downtime.
Annual
Inspection
Insurance
regulations or local laws will
require a periodic inspection of
the pressure vessel by an
Authorized Inspector. Sufficient
notice is generally given to
permit removal of the boiler
from service and preparation for
inspection. This major
inspection can often be used to
accomplish maintenance,
replacements, or repairs that
cannot easily be done at other
times. This also serves as a
good basis for establishing a
schedule for annual, monthly, or
periodic maintenance programs.
While
this inspection pertains
primarily to the waterside and
fireside surfaces of the
pressure vessel, it provides the
operator an excellent
opportunity for detailed
inspection and check of all
components of the boiler
including piping, valves, pumps,
gaskets , refractory, etc.
Comprehensive cleaning, spot
painting or re-painting and the
replacement of expendable items
should be planned for and taken
care of during this time. Any
major repairs or replacements
that may be required should
also, if possible, be
coordinated with this period of
boiler shutdown. Replacement
spare parts, if not on hand,
should be ordered sufficiently
prior to this shutdown.
Have
available information on the
boiler design, dimensions,
generating capacity, operating
pressure, time in service,
defects found previously, and
any repairs or modifications.
Also have available for
reference records of previous
inspections. Be prepared to
perform any testing required by
the inspector including
hydrostatic testing of the
equipment.
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