BOILERS QUESTIONS FILL IN THE BLANKS / ANSWER
Where is a fusible plug
installed on a Scotch or auxiliary
boiler?/At or near the center of the crown sheet of the combustion chamber.
Fusible plugs are
installed in fire-tube boilers to
_____________./warn the engineer of low water level
If the combustion control
system of an automatically fired auxiliary boiler fails to sustain burner
ignition after a normal shutdown, you should check for a/an __________./faulty
photocell detector
Before any work is to be
carried out on a burner in an
automatically fired auxiliary boiler, you should always _____________./close all manually operated
fuel valves
Generating tubes in waste
heat boilers are finned to
____________./increase the rate of heat transfer
If an operating auxiliary
boiler has a water pH reading of 7, you should ______________./treat the water
with caustic soda
Which of the following
conditions is responsible for the fuel oil to atomize when using a steam
atomizer in an auxiliary
boiler?/Expansion of the steam in the furnace.
A failure to any
component of a flame safeguard control for an automatically fired auxiliary
boiler, will result in
______________./the prevention of automatic restart
When an auxiliary boiler
is on the line, the output of the flame scanner can be checked by placing a
microammeter in series with the photoelectric cell circuit. The readings on
high fire should be ____________./higher than those at low fire
A feed pump for an
auxiliary boiler might lose suction if the ____________./feedwater is too hot
The water in a steaming
auxiliary boiler should be tested daily for ______________./chlorides
The programmed control
system of an automatic auxiliary boiler
will terminate the light off process during the
prepurge period if air flow is not sensed and _________./the damper is
not sufficiently open
The flame safeguard
control system of a large automatic
auxiliary boiler will provide fuel shut off in the case of high
____________./steam pressure
The boiler water
alkalinity in a coil-type auxiliary boiler should be maintained at the pH
recommended by the boiler manufacturer to _________________./reduce corrosion
in the heating coil
Coast Guard Regulations
(46 CFR) require the controls for automatically fired auxiliary boilers, must
be fitted with visible indicators to signal __________./fuel oil shutoff due to
flameout
When a waste heat boiler
is installed in the exhaust of a main propulsion diesel engine, the exhaust gas
bypass would be used ____________./at low loads to prevent corrosion in the
boiler
How is the concentration
of dissolved oxygen in the feedwater of
an auxiliary boiler maintained at acceptable limits?/Oxygen is liberated by
maintaining the highest practical feedwater temperature.
Which of the listed types
of control systems is required by Coast Guard Regulations (46 CFR) for large
automatic auxiliary boiler heating
equipment?/All of the above
Which of the following
items is necessary for all waste heat boiler installations, regardless of
design or manufacturer?/Control of evaporation
When it becomes necessary
to replace any tubes in a water-tube
auxiliary boiler to eliminate leaks at the tube seats, the replacement tubes
should be ____________./rolled, beaded, and seal welded around the bead edge
Automatic combustion
control systems for some auxiliary
boilers are designed to cycle burners on in response to ____________./low steam pressure
It is desirable for an
auxiliary boiler safety valve to pop open and reseat quickly to
__________./prevent wire drawing of the disc and seat
Coast Guard Regulation
(46 CFR) requires that after undergoing
extensive repairs, an auxiliary boiler, with a maximum allowable working
pressure of 60 psig (411.89 kPa), should be hydrostatically tested at a pressure
of ______________./90 psig (617.83 kPa)
The purpose of the
programmed purge cycle on an
automatically fired auxiliary boiler is to _______________./remove
explosive vapors from the furnace
An auxiliary boiler
equipped with a return flow fuel atomization system, has a _____________./variable
fuel return pressure
Heavy soot accumulations
in an auxiliary boiler could be caused by _____________./improper burner
maintenance
Prior to lighting off a
cold automatically fired auxiliary boiler, you should _____________./check and
regulate the water level
Within the cycle of a
forced circulation auxiliary water-tube
boiler, part of the water flashes into steam, and the remaining hot water is
_________________./collected in the lower portion of the steam accumulator for recirculation back to the heating coil or
water tank
Ignition failure in an
automatically controlled auxiliary boiler could be caused by
_____________./carbon deposits on the flame scanner
In a coil-type auxiliary
water-tube circulation boiler
_____________./unevaporated feedwater collects in the bottom of the
flash chamber
A dirty atomizer sprayer
plate in the burner of an auxiliary boiler, would be indicated by
____________./an unevenly shaped burner flame
Which of the following
actions takes place in the control circuit of an automatically fired auxiliary
boiler when the desired steam pressure is obtained?/The high limit control
secures power to the entire oil firing
system.
Throttling a burner air
register on an auxiliary boiler could
result in ____________./smoky boiler operation
A burner producing black
smoke in an automatic auxiliary boiler, would be caused by a/an
______________./incorrect primary air setting
Which of the following
actions should be taken when an
auxiliary boiler is operation?/Inspect for oil and water leaks.
Failure of the burner
flame in an automatic auxiliary boiler would probably be a result of
______________./water in the fuel oil
If the flame of an
automatically fired auxiliary boiler
tends to move away from the burner tip when the
firing rate is changed from low to high, you should ____________./adjust damper linkage to slow
the opening rate of the dampers
Which of the following
procedures decreases the total dissolved
solids concentration in the water of an auxiliary boiler?/Bottom blowing
If the fire goes out in
an automatically fired auxiliary boiler and the burner continues to supply
fuel, there is a potential danger of ______________./a severe furnace explosion
Improper maintenance of
an automatic auxiliary boiler oil burner could result in
______________./decreased boiler efficiency
In accordance with Coast
Guard Regulations (46 CFR), water level controls utilized in a small
automatically fired auxiliary heating
boiler, shall be tested ______________./slowly by lowering the boiler water
level
After a normal, or safety
shutdown, automatic combustion control systems for an auxiliary boiler are
designed to prevent the immediate
refiring of a burner in order for the ________________./furnace to be repurged
When preparing to light
off a cold boiler equipped with a return flow fuel oil system, the
recirculating valve directs the flow of oil ____________./back to the suction
side of the service pump
Which of the following
conditions will cause only one of the
burner solenoid valves to close on an automatically fired, two burner unit,
auxiliary boiler?/A faulty coil in one of the solenoid valves
The burner assembly on an
automatically fired auxiliary boiler
fitted with variable capacity, pressure atomizing burners, maintains steam
pressure by ______________./changing fuel oil return pressure
While an auxiliary boiler
is operating at design load, which of the following actions will occur if the
automatic combustion control system
detects a steam pressure drop?/The fuel oil valve and air damper will open
wider.
According to Coast Guard
Regulations (46 CFR), when an
automatically fired boiler has a flameout, which of the following actions should occur FIRST?/The
fuel valve should be de-energized.
The water in an auxiliary
boiler should be chemically tested daily for alkalinity and
_________________./chloride content
The primary function of a
flame safeguard system, as used on an automatically fired auxiliary boiler, is
to prevent ____________./explosions in
the boiler furnace
The purpose of designing
some waste heat boilers with sinuous
fire tubes, is to ____________./increase the rate of heat transfer to the
waterside
The amount of chloride
content in the water of an auxiliary boiler can be reduced by
____________./blowing down the boiler
The fuel supply system to
an automatic auxiliary boiler, will be automatically shutdown if the boiler
______________./water level is abnormally low
In readying an auxiliary
water-tube boiler for a routine hydrostatic test, which of the following
procedures should be undertaken prior to filling the boiler with fresh
water?/The boiler vent valves should be opened.
Constant capacity
pressure atomizing fuel oil burners
installed on automatically fired auxiliary boilers, respond to
variations in load demand by ____________./automatically cycling the burner on
and off
Which of the following
conditions could cause the feed pump for an auxiliary boiler to lose
suction?/Excessive feedwater temperature
Coast Guard Regulations
(46 CFR) specify that the fuel oil ignition system, on a small automatically
fired auxiliary boiler, shall be energized ____________./only before, or
simultaneously with, the opening of the fuel oil valve
The amount of oil
atomized by the return flow variable
capacity atomizer, used with some automatically fired boilers, is controlled by the
_______________./oil pressure in the oil return line
An automatically fired
auxiliary boiler is required by Coast Guard Regulations (46 CFR) to be shutdown
as a result of ____________./low water level
Fins are installed on the
generating tube surfaces in waste heat boilers to ____________./increase the
rate of heat transfer
Subtracting the return
flow meter reading from the supply flow meter reading on a boiler equipped with
a return flow fuel oil system, determines the amount of oil
____________./burner throughput
In a fire-tube auxiliary
boiler, you should expect to find the thickest scale on the waterside of the
____________./crown sheet
If the feed pump for an
auxiliary boiler fails to deliver the feed water to the boiler, the cause may
be ____________./abnormally high feedwater temperature
When lighting off an
auxiliary boiler, which of the problems
listed could cause the burners to sputter?/Water in the fuel oil
Which of the following
actions should normally be taken during
each watch when the auxiliary boiler is in operation?/Inspect for oil or water
leaks.
When there is a flame
failure in an automatically fired
auxiliary boiler, the ____________./fuel supply is shut off
Excessive vibration of an
automatically fired auxiliary boiler can
be caused by _____________./combustion pulses
Burner ignition failure
in an automatically fired auxiliary boiler would be caused by ____________./a
burned out solenoid in the oil supply valve
The purpose of a
temperature sensing device installed in the stack of a small automatically
fired auxiliary steam boiler is to secure the oil burner _______________./in
the event of a flame failure
The water in an auxiliary
boiler should be tested for chloride
content to determine ______________./salt contamination
According to Coast Guard
Regulations (46 CFR), the fuel strainer
installation located in the supply lines to the fuel pump of an auxiliary
boiler, can be provided with _________./all
of the above
Excessive return oil
pressure from a variable capacity return
flow fuel oil burner system on an automatic auxiliary boiler, will cause
____________./burner smoking
The concentration of
total dissolved solids in the water of an auxiliary boiler can increase as a
result of __________./seawater contamination
Automatic burner shutdown
in an auxiliary boiler, as a result of a
component failure in the flame safeguard
controls, will _______________./prevent the boiler from automatically
relighting
When an auxiliary boiler
is secured and you expect to relight the
unit within six hours, you should _____________./maintain a head of steam not
less than 10 psig
If the combustion control
system of an automatically fired auxiliary boiler fails to restart from the
normal shutdown mode, you should check for ______________./all of the above
Bottom blow valves are
installed on auxiliary water-tube boilers to _____________./remove suspended
and precipitated solids from the boiler water
The water in an operating
auxiliary boiler should be tested for alkalinity and chloride content each
__________./day
Coast Guard Regulations
(46 CFR) require that the flame
safeguard control system for an automatic boiler, should
_____________./be capable of closing the fuel valves in not more than 4 seconds
after a flame failure
Which of the following
statements describes how the fuel oil enters the whirling chambers of the
sprayer plates used in a auxiliary boiler return flow fuel oil system?/Through
tangential slots in the sprayer plate.
For proper operation,
auxiliary boiler feedwater must have which of the following
characteristics?/Proper alkalinity
The most common cause of
scale formation in an auxiliary boiler is ______________./concentrations of
calcium sulfate in the boiler water
Before an auxiliary
boiler is shutdown for an extended
period of time, the water in the boiler should have a pH value of
____________./10
Which of the following
statements concerning automatically controlled auxiliary boiler system alarms
complies with applicable Coast Guard
Regulations (46 CFR)?/Visible indicators require manual resetting.
Excessive alkalinity of
the water in an auxiliary boiler can cause ____________./caustic embrittlement
of the boiler metal
Two solenoid control
valves are required on large automatic auxiliary boilers, and will
simultaneously shut off the fuel in the event of _______________./low water
Diesel engine waste heat
boiler construction is usually of the fire-tube or _____________./water-tube
type
The procedures
recommended for auxiliary boilers having high salinity include
____________./securing the boiler and giving it a bottom blow
The solenoid valves in
the fuel oil supply line to an
automatically fired auxiliary boiler, are automatically closed by ______________./high steam pressure
In the event of a flame
failure in an auxiliary water-tube boiler, you must ______________./purge the
furnace of any combustible gases before attempting to relight the fire
Improper maintenance of
the fuel oil burners in an
automatically fired auxiliary boiler, could result in ____________./increased fuel consumption
The concentration of
dissolved solids in the boiler water of an auxiliary boiler could increase as a
result of ___________./phosphate
treatment
Failure of the feed pump
to deliver feedwater to an auxiliary boiler
could be caused by _______________./grounded probes in the water level control
Why should the main steam
stop valve of an auxiliary boiler be eased off its seat and then gently closed
before lighting off?/To ensure that the valve will not be seized shut when hot.
Flame failure in an
automatically fired auxiliary boiler can result from a/an
______________./clogged fuel nozzle
If the fuel/air ratio in
an automatically fired auxiliary boiler is insufficient, the result could lead
to __________./all of the above
Which of the following
actions should normally be taken during each watch when the auxiliary boiler is
in operation?/Observe general boiler performance
Under which of the
following conditions must the combustion control system for a small automatic
auxiliary boiler secure the burner?/Flame failure
A pulsating flame,
accompanied by a burner developing black smoke in an auxiliary boiler, is an
indication that the _____________./fuel
oil pressure is too low
Which of the following
actions should normally be taken during each watch when the auxiliary boiler is
operation?/Blow down the water gage glass
Flame failure in an
operating automatically fired auxiliary boiler can result from a
_____________./clogged fuel nozzle
A failure of any
component of a flame safeguard control for an auxiliary boiler will result in
____________./automatic burner shutdown
The daily inspection of
an operating auxiliary boiler should include ____________./checking for
external fuel and water leaks
If a tube ruptures in a
water-tube auxiliary boiler due to low water, you should ____________./secure
both the fires and the feed inlet valve
An automatically fired
auxiliary boiler with carbon deposits formed on its burner electrodes, will
experience _________./ignition failure
An exhaust gas bypass is
installed on a waste heat boiler in order to ____________./minimize moisture
condensation in the boiler gas passages at low loads
The fuel oil supply
system to an automatic auxiliary boiler, will automatically shutdown if the
boiler _____________./burner flame is extinguished
The diesel engine exhaust
gas bypass, as fitted with some waste heat boilers, is installed to
____________./prevent boiler corrosion at low engine loads
Oxygen corrosion in
auxiliary boilers is prevented by
treating the boiler feed tank with either sodium ____________./sulfite or hydrazine
A bypass line provided
around a waste heat auxiliary boiler in a diesel engine exhaust system, may be
used to avoid boiler
____________./corrosion at low engine loads
The concentration of
total dissolved solids in the water of an auxiliary boiler can increase as a
result of ___________./seawater contamination
Which of the listed
sequence of events occurs when an automatic auxiliary boiler is prepurged?/The
damper on the inlet side of the furnace is moved to the open position for a
given number of seconds and then moved to the low fire position.
High stack temperature
occurring in an auxiliary boiler could be a result of ____________./secondary
combustion in the uptake
A firebox explosion in an
automatically fired auxiliary boiler may be the result of
______________./insufficient purging before lighting off
The PRIMARY function of a
waste heat boiler is to _________./recover heat which otherwise would be lost
A coil-type automatically
fired auxiliary boiler is to be laid up wet for an indefinite period. The
boiler water should be treated to ensure that ____________./the manufacturer's
recommended pH is maintained
Coast Guard Regulations
(46 CFR) require all automatically fired low pressure heating boilers to have
an automatic ____________./fuel cutoff
as a result of low water
Control of the fuel oil
metering valve in an automatically fired auxiliary boiler is accomplished by a
___________./steam pressure sensing device with linkage to the damper air vanes
A safety valve on an
auxiliary boiler simmers constantly and can not be stopped by several quick
blow-offs using the hand relieving gear. The problem may be __________./a
damaged seat
A burner responsible for
producing black smoke in an automatic auxiliary boiler, would be caused by a
__________./dirty fuel nozzle
Which of the following
types of feedwater regulators is
commonly used with a water-tube, natural circulation, auxiliary boiler?/Thermo mechanical
A SECONDARY function of a
waste heat boiler is to _________./reduce engine exhaust noise
An auxiliary boiler is
equipped with a return flow fuel
atomization system, which uses a/an _____________./constant fuel supply
pressure
Overfiring of a hot water
boiler may be caused by _________./faulty limit controls
The pressuretrol is
installed on an auxiliary boiler to
sense steam pressure changes, it _______________./automatically
regulates the quantity of oil and air flow to the burner
If the combustion control
system of an automatically fired auxiliary boiler fails to relight the burner
after a normal shutdown, you should check for a/an ____________./faulty
photocell detector
A waste heat boiler is
installed on some diesel propelled vessels to _____________./provide steam for
the turbogenerator
Why should handhole
gaskets not be allowed to leak on an auxiliary boiler?/The gasket and its
seating surface may become wire drawn.
Automatic combustion
control systems for auxiliary boilers are designed to cycle burners on and off
in response to the _______________./steam pressure
The variation in the
amount of fuel oil burned in the
operation of an auxiliary boiler, utilizing a return flow type
atomization system, is a function of the _____________./fuel oil back pressure
Which of the following
conditions could cause black smoke to be discharged from the stack of an
auxiliary boiler equipped with turbine-driven rotary cup atomizers?/Improper
turbine shaft speed in the atomizer assembly.
The maximum pressure
developed by a waste heat boiler is determined by the main engine exhaust
____________./gas temperature
Which of the listed parts
on a fire-tube auxiliary boiler requires a written report to the
Officer-in-Charge of Marine Inspection when renewed?/Fusible plugs
Automatic combustion
control systems for some auxiliary
boilers are designed to cycle burners on and off in response to
____________./steam pressure
Waterside scale in a
fire-tube boiler may cause ___________./overheated tubes
When an auxiliary boiler
is panting and emitting black smoke, you
should _____________./increase the air supply
Bottom blow valves are
installed on auxiliary water-tube boilers to _____________./remove settled
solids from the water drum
The correct procedure for
giving an auxiliary boiler a bottom
blow, is to begin _____________./when the boiler has been secured long enough
for most solids to settle
With which of the
following types of diesel engine
arrangements is a waste heat boiler most likely to produce the maximum
steam pressure, temperature, and flow conditions?/Supercharged,
four-stroke/cycle diesel engine
During maintenance
inspections of a fire tube auxiliary
boiler, you should check for _____________./all of the above
The constant capacity,
pressure atomizing, fuel oil burners designed to meet a wide variation in the
steaming loads of an auxiliary boiler, are ________________./automatically
cycled on and off in response to demand
Coast Guard Regulations
(46 CFR) permit tubular type water gage glasses on auxiliary boilers, provided
the maximum allowable working pressure
does not exceed ________./250 psi
In an automatically fired
auxiliary boiler, restarting from the normal shutdown cycle in response to
steam demand, is initiated by a/an ______________./pressuretrol measuring only
the steam pressure
Which of the following
methods is typically employed in the design of waste heat boilers to obtain
maximum heat transfer, while
maintaining low overall weight?/Steel fins are installed on the generating tube
surfaces to increase the effective surface area.
According to Coast Guard
Regulations (46 CFR), which of the following pressures is the highest boiler
pressure where a tubular type gage glass may be installed?/250 psig
At the beginning of the
prepurge period on an automatic auxiliary boiler equipped with a programmed
control system, the unit will not restart if airflow is not sensed and ______________./the damper is not
sufficiently opened
A properly adjusted
safety valve for an auxiliary boiler will ____________./open with a sharp,
clear pop at its set pressure
When conducting a
hydrostatic test on a water-tube
auxiliary boiler, the test water should be heated to a temperature of at
least 70°F. This is done to
____________./help prevent the formation of condensation on the
tube exteriors
A photoelectric cell
installed in an automatically fired auxiliary boiler burner management system
________________./opens the burner circuit upon sensing a flame failure
The maximum allowable
working pressure on a packaged auxiliary boiler is 200 psig. The normal working
pressure for one particular packaged boiler is 175 psig. Which of the following
safety relief valve settings would be proper for this boiler?/195 psig
Coast Guard Regulations
(46 CFR) require that oil fired automatic steam boilers, and hot water boilers
shall be equipped with a prepurge programming control that will assure at least ______________./4 air changes
A smoking burner with a
pulsating flame in an auxiliary boiler, is an indication that the
______________./fuel/air ratio is incorrect
On an automatically fired
auxiliary boiler, the steam pressure limit switch is wired into the burner
electric circuit to ______________./shut
off the burner when the cutoff pressure is reached
Excessive vibration from
an auxiliary boiler could be caused by ____________./all of the above
After lighting off a
cold, automatically fired, auxiliary boiler, as steam begins to form, you
should ___________./close the air cock
In a coil-type forced
circulation auxiliary water-tube boiler
_____________./hot water flashes to steam in the flash chamber
If poor combustion occurs
in an auxiliary boiler due to an air damper linkage being out of adjustment,
you would adjust the linkage and then _____________./check the photocell window
for carbon deposits
Which of the automatic
boiler controls listed should be tested
prior to lighting off an auxiliary boiler?/Low water level cutoff switch
Which of the following
conditions would cause "panting" in a steaming auxiliary
boiler?/Insufficient combustion air
Which of the following statements
concerning the operation of a coil-type forced circulation auxiliary
water-tube boiler is
correct?/Unevaporated boiler water collects in the bottom of the accumulator.
Coast Guard Regulations
(46 CFR) require electric hot water supply boilers to be provided with a/an
_____________./temperature limiting device
In a forced circulation
auxiliary boiler, steam is formed in the ____________./steam accumulator (flash
chamber)
Ignition failure in an
automatically controlled auxiliary boiler can be caused by
______________./carbon deposits on the electrode
A sudden flame failure in
an operating auxiliary boiler, equipped with an automatic combustion control
system and burning light fuel, could be attributed to a______________./loose
connection on the photocell
The flame safeguard
controls of a large automatically fired auxiliary boiler, may consist of a
____________./photoelectric cell
Coast Guard Regulations
(46 CFR) permit the use of which of the following fuel oil ignition methods on
automatic auxiliary boilers?/Light oil
pilot
Which of the following
statements concerning fire-tube boilers
is correct?/Combustion gases flow through the tubes.
Which of the following
statements about a coil-type forced circulation auxiliary water-tube boiler is
correct?/Response to steam demand is comparatively rapid.
Ignition failure in an
auxiliary boiler can be caused by _____________./carbon deposits on electrodes
The purpose of the safety
relief valves installed on an auxiliary
boiler is to ____________./reduce excess steam pressure in the boiler
The safety valve
installed on a coil-type auxiliary boiler is located on the ____________./flash
chamber
Which of the following
statements is true concerning pressure
limit switches and pressuretrols installed on
auxiliary boilers?/They consist of a bellows assembly, linked with a
snap action switch, through a pressure
adjusting mechanism.
The purpose of try-cocks
used on an auxiliary boiler is to ____________./provide an alternate means of
determining the water level, if the gage glass fails
The gage glass on a
coil-type auxiliary boiler is connected to the ______________./accumulator
When the steam pressure
drops below a set value on an
automatically fired auxiliary boiler, fitted with rotary cup atomizers,
the combustion control system will _________./increase the fuel oil control
valve opening
Automatically fired
auxiliary boilers use fuel oil strainer arrangements of either the simplex type
or _____________./duplex type
In an auxiliary boiler
steam and water system, the highest pressure will be in the
____________./feedwater system
The fuel oil strainers in
the fuel oil service system of an automatically fired auxiliary boiler are
permitted by the Coast Guard Regulations (46 CFR) to be either the simplex type
or the ____________./duplex type
The principal purpose of
refractory and insulation installed in
the firebox of an auxiliary boiler is to
____________./protect the inner casing and reduce heat loss
Fins are installed on the
fireside of the water-tubes, used in waste heat boilers, to
____________./increase the heat transfer surface area
Auxiliary boilers can be
classified as ________________./all of the above
Fins are installed on the
fireside of the water-tubes used in waste heat boilers to
____________./increase the rate of heat transfer
The rate of heat transfer
in a water-tube auxiliary boiler can be increased by ____________./installing
fins on the firesides of water-tubes
Large steam drums are not
required in the design of a coil-type
auxiliary water-tube boiler because _____________./steam and water are
separated in the accumulator (flash
chamber)
Before any work is done
on a burner in an automatically fired
auxiliary boiler, you should always ___________./close all manually operated
fuel valves
Constant capacity,
pressure atomizing, fuel burners designed to meet a wide variation in steaming
loads on an auxiliary boiler, are _____________./cycled on and off in response
to steam demand
The fuel oil strainers
located in the fuel oil service system
of an automatic auxiliary heating boiler are either the duplex type or the
_______________./simplex type
Auxiliary boilers are
divided into several classifications, one of which is
______________./water-tube forced circulation
Downcomers installed on
auxiliary package boilers are protected
from direct contact with hot gases by ___________./refractory and insulation
Which of the listed
problems will happen when the water
level of a fire-tube type auxiliary boiler approaches the crown
sheet?/The fusible plugs will melt.
A waterside fusible plug,
installed in a fire-tube auxiliary boiler _____________./by design, is drilled
with a tapered hole so that boiler water pressure holds the fusible metal in
the bronze body
A horizontal fire-tube
package boiler, incorporating a two-pass
design, is basically constructed with ____________./removable spiral metal gas
retarders being inserted in the tubes to decrease the gas velocity to a
minimum, thus extracting the maximum
caloric heat value
The fusible plugs used in
fire-tube auxiliary boilers are installed in the _____________./crown sheet
Waste heat boilers may be
equipped with vents on the feed water heater heads to ____________./prevent air
binding
The tube sheets installed
in a fire-tube auxiliary boiler are normally connected by
____________./fire-tubes and stay-tubes
In a coil-type forced
circulation auxiliary water-tube boiler,
____________./steam demand response is comparatively rapid
Which type of pump is
typically used to supply fuel to a unit type auxiliary boiler?/Rotary
According to Coast Guard
Regulations (46 CFR), the maximum allowable boiler pressure in which a tubular
gage glass may be installed is _________./250 psig
A distorted furnace in a
fire-tube auxiliary boiler may be the result of ____________./overheating, due
to waterside deposits
The principal purpose of
refractory and insulation installed in
the firebox of an auxiliary boiler is to
____________./protect the inner casing and reduce heat loss
Why should the main steam
stop valve of an auxiliary boiler be eased off its seat and then gently closed
before lighting off?/To ensure that the valve will not be seized shut when hot.
According to Coast Guard
Regulations (46 CFR), the highest boiler pressure where a tubular type gage
glass may be installed is ______________./250 psig
Before any work is to be
carried out on a burner in an
automatically fired auxiliary boiler, you should always _____________./close all manually operated
fuel valves
During unsafe firing
conditions in a large automatic
auxiliary boiler, various control actuators are interlocked with the
burner circuit to prevent start-up, in addition to safety shutdown. These
controls are referred to as
____________./limit controls
When checking for the
presence of sulfite in the feedwater of an auxiliary boiler, you are in essence
checking ____________./to ensure the
compound additions are adequate for
controlling dissolved oxygen
Coast Guard Regulations
(46 CFR) permit the use of which of the listed fuel oil ignition methods on an
automatically fired auxiliary boiler?/A high energy electric spark
To test the operation of
the flame failure switch of an operating
automatically fired auxiliary boiler, you should _____________./close the
manual fuel valve with the burner firing
On auxiliary boilers
using individual flame scanners to
monitor the main and pilot flames, the main flame scanner should be
sighted to ______________./avoid detecting the pilot flame
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