287 terms

boiler exam study guide 1

High Pressure Boilers 4th ed. ch 1-11 exams (minus graphical questions)

Terms in this set (...)

15 psi
A low pressure steam boiler has a maximum allowable working pressure (MAWP) of up to ___.
One boiler horsepower
The evaporation of 34.5 lb of water/hr from and at a feedwater temperature of 212°F
through the tubes
In a firetube boiler, the heat and gases of combustion pass ___.
in high or low pressure plants
A firetube boiler may be used ___.
a firetube boiler
Because of the large volume of water, the boiler most likely to cause a boiler explosion is ___.
A horizontal return tubular (HRT) boiler is a ___ boiler.
As steam pressure in a boiler increases, there is a corresponding increase in the ___.
a boiler explosion
A sudden drop in boiler steam pressure without a corresponding drop in boiler water temperature could result in ___.
heating surface
The part of a boiler that has the heat and gases of combustion on one side and water on the other side is known as the ___.
The comparison, or ratio, of heat supplied in fuel to heat absorbed by water is defined as ___ efficiency.
boiler heating surface
Baffles are designed to direct the gases of combustion so that they come into close contact with the ___.
The steam and water drum of watertube boilers is dished (concave) to eliminate the need for ___.
To increase the life of a furnace refractory, some watertube boilers are equipped with ___.
high ceilings, less floor space, and the use of staybolts
Vertical firetube boilers require ___.
around the tubes
In a watertube boiler, the heat and gases of combustion pass ___.
The ___ boiler has a large volume of water in relation to horsepower size.
a firetube boiler (high or low pressure)
Stays and braces are needed to prevent bulging in ___.
The ___ boiler was developed to provide steam at higher pressures.
The mud drum is the lowest part of the water side of a(n) ___ boiler.
Boiler plates and staybolts are subjected to ___ stress.
American Society of Mechanical Engineers (ASME)
Safety valve connections must be approved by the ___.
safety and efficiency
Boiler fittings are necessary for ___.
safety valve
The most important fitting on a boiler is the ___.
safety valve
To prevent failure from pressure over the MAWP, all steam boilers must be equipped with at least one ___.
prevent the boiler from exceeding its MAWP
A safety valve will ___.
pop open
Safety valves are designed to ___.
before the main safety valves are set to open
Superheater safety valves are set to open ___.
at least 75% of the popping pressure
When testing a safety valve by hand, there must be ___.
safety valve manufacturer or manufacturer's authorized representative
Any repairs to a safety valve should be done by the ___.
qualified person who is familiar with the contruction and operation of a safety valve
The setting or adjusting of a safety valve should only be done by the ___.
an accumulation test is put on the boiler
If it is necessary to test the relieving capacity of a safety valve, ___.
pounds of steam per hour capable of discharging under a given pressure
The relieving capacity of a safety valve is measured in ___.
reduce turbulence in the gauge glass to get a more accurate reading of the water level in the boiler
The main purpose of a water column is to ___.
a secondary means of determining water level in a boiler.
Try cocks are ___.
using the try cocks
When replacing a broken gauge glass, the water level is checked by ___.
once a shift
The water column and gauge glass should usually be blown down ___.
warn the operator of high or low water
A whistle valve is used to ___.
pounds per square inch
A steam pressure gauge is calibrated in ___.
high temperature of steam
A siphon protects the steam pressure gauge from ___.
The pressure at the base of a vertical foot of water is ___ psi.
highest part of the steam side of the boiler
The boiler vent is located at the ___.
there is 10 to 15 psi of steam pressure on the boiler
The boiler vent is open when warming up a boiler until ___.
changing the direction of the steam flow
Steam separators work on the principle of ___.
upper part of the steam and water drum
The dry pipe is located in the ___.
boilers equipped with superheaters
Cyclone separators are used in ___.
its corresponding temperature and pressure
Saturated steam is steam at ___.
temperature increases with no increase in pressure
When steam is superheated the ___.
a continuous flow of steam
Superheater tubes are protected from warping or burning out by ___.
removed from boiler tubes for better heat transfer
Soot should be ___.
watertube boilers
Soot blowers are mainly found on ___.
cut through the boiler tubes in a very short period of time
Steam impinging on boiler tubes would ___.
highest part of the steam side of the drum
To ensure that moisture-free steam goes to the soot blower, the steam line to the soot blower must come off the ___
two main steam stop valves
Boilers in battery equipped with manhole openings must have ___ according to the ASME code.
Os&y gate
Main boiler stop valves must be ___ valves.
installed as close to the shell of the boiler as practical on the main steam line
The ASME code will allow an automatic nonreturn valve to be used as a main steam stop valve. If one is used it must be ___.
offer no restriction to the flow of steam
The main steam stop valves should be gate valves because they ___.
slightly lower than line pressure
When the boiler is equipped with hand-operated, main steam stop valves, to cut the boiler in on the line, the steam pressure on the incoming boiler should be ___.
closed, locked, and tagged.
When a boiler is being inspected, the two main steam stop valves are ___.
free-blowing drain should be open
During boiler warm-up, to remove any condensate trapped between the two boiler stop valves the ___.
expansion bends are used
During normal usage, the boiler main steam line expands and contracts. To allow for this ___.
two bottom blowdown valves
According to the ASME code, boilers operating at 100 psi or over must have ___.
opened first and closed last
When blowing down a boiler equipped with a quick-opening valve and a screw-type valve, the quick-opening valve is ___.
between the boiler and the slow-opening (screw-type) valve
If a quick-opening valve is used as a bottom blowdown valve, it must be located ___.
2 ½
The maximum size of the bottom blowdown line and the surface blowdown line is ___".
mud drum
Bottom blowdown lines on a watertube boiler are located on the ___.
boiler water analysis
The most accurate means of deciding the frequency of blowdown of a boiler is determined by a ___.
impurities that float on the surface of the water
Surface tension on the water in the steam and water drum is increased by ___.
blowdown tanks are used
To protect sewer lines from the high temperature and high pressure coming from the boiler blowdown lines, ___.
20,000 lb of water/hr
A boiler generating 20,000 lb of steam/hr must be supplied with at least ___.
in the open deaerator feedwater heater
Oxygen and other noncondensable gases are separated form the feedwater ___.
steam, feedwater, fuel, and draft
The four systems required to operate a steam boiler are ___.
one lb of water
In order to produce one pound of steam, it is necessary to evaporate ___.
Steam that has lost its heat and has turned back into water is ___.
be used for process work and heating
Steam is extracted from the turbine after it has passed through some of the turbine stages to ___
to the feedwater pump
Water from an open deaerating feedwater heater flows ___.
one steam and one electric feedwater
A safe and efficient boiler plant should include ___ pump(s).
passed through tubes to cause steam to condense, causing a vacuum
A surface condenser has water ___.
On the feedwater line near the boiler is a check valve and a stop valve. The valve closest to the shell of the boiler is the ___ valve.
volume of air passing through the venturi tube
On a boiler burning low pressure gas, the volume (amount) of gas burned is controlled by the ___.
allow one strainer to be cleaned without securing the boiler
On the fuel oil system, the purpose of the duplex strainers on the suction line between the tank and fuel oil pump is to ___.
A draft fan located between the boiler and chimney is used in a(n) ___ draft system.
more heat energy, thus producing more work
When steam is superheated it has ___.
reduces back pressure and steam flow rate
The vacuum on the exhaust side of the turbine ___.
above the feedwater pump(s)
The open feedwater heater is located ___.
No. ___ fuel oil must be heater in order to be pumped.
hand firing was inefficient in larger-sized boilers
Coal stokers were developed because ___.
can come in closer contact with the oxygen for complete combustion
Pulverized coal has the consistency of talcum powder so that it ___.
air or gases to flow
Draft is defined as a difference in pressure that causes ___.
high pressure
Air is mixed inside of the burner register in a(n) ___ gas system.
difference in temperature of a column of gas inside the chimney from a column of air outside the chimney
Natural draft is produced by a(n) ___.
Pulverized coal is burned in ___ in the furnace.
gas company representative
Gas leaks should be located and repaired by a ___.
Water weighs approximately ___ lb/gal.
maintain a water level in the feedwater heater if there are insufficient condensate returns
The automatic city water makeup valve found on an open feedwater heater is used to ___.
maintain a consistent water level in the boiler
The purpose of a feedwater regulator is to ___.
at the NOWL
Feedwater regulator sensing elements are located ___.
diameter of steam piston, diameter of water piston, and length of pump stroke
The sequence of three numbers found on the data plate attached to a reciprocating feedwater pump indicates the ___.
A(n) ___ draft fan must be used to overcome resistance caused by gases of combustion leaving the boiler when an economizer is used.
pump and the discharge valve
A reciprocating feedwater pump must have a safety relief valve located between the ___.
feedwater using gases of combustion
An economizer is used in large boiler plants to heat ___.
is converted into pressure
The theory of operation of a centrifugal pump is that the centrifugal force of a rotating element ___.
open or closed
Centrifugal feedwater pumps can be started with their discharge valves ___.
positive displacement pump
A turbine feedwater pump differs from a centrifugal feedwater pump in that it is a ___.
safety relief valve must be installed on the discharge line
To protect the turbine pump from excessive pressure, a(n) ___.
check valve can be repaired without taking the boiler off-line
The feedwater stop valve on the feedwater line is located closest to the shell of the boiler so that the ___.
the feedwater pump to become steambound
Water temperature that is too high in the open feedwater heater could cause ___.
oxygen pitting in the boiler
Water temperature that is too low in the open feedwater heater could cause ___.
when both superheated and saturated steam are needed, with a pressure-reducing station, and with feedwater addition to desuperheat the steam
A line desuperheater is typically used ___.
heat energy
Burning a fuel releases ___.
pressure buildup, which would cause an oil spill
A clogged vent line on a fuel oil tank being filled with fuel oil could result in a ___.
signs of sludge and water are evident in the tank
A high suction line on a fuel oil tank is used when ___.
circulate fuel oil during warm-up, return fuel oil that bypasses the burner, and return fuel oil from the relief valve
The purpose of the fuel oil return line is to ___.
live steam and air
In both steam and air atomizing burners, atomization is accomplished by ___.
manual reset valve
In a low pressure gas burner, a ___ shuts off the gas supply if a low water condition exists.
indicate gallons of fuel oil in the tank
The pneumercator is used to ___.
a large pressure drop
An indication of a dirty fuel oil strainer would be ___ across the strainer.
both the suction and discharge sides
Duplex strainers are found on ___ of the fuel oil pump.
Fuel oil heaters must be used when burning No. ___ fuel oil.
on the discharge side of
Fuel oil heaters must be protected from excessive fuel oil pressure because they are located ___ the fuel pumps.
a spinning cup and high velocity air
The rotary cup burner atomizes fuel oil using ___.
rotating, high pressure oil coming out of the plug or sprayer plate
In a pressure atomizing burner, atomization is accomplished by ___.
desired pressure at the burner
A gas pressure regulator is used to control the ___.
as an automatic gas shutoff valve
A solenoid valve is a direct-acting valve in the gas system and is used ___.
warm air is used
To prevent caking and to dry the coal entering the pulverizer, ___.
supply air for combustion
Blowers are used in a high pressure gas system to ___.
air damper, butterfly valve, and modulating motor and linkage
The air-to-gas ratio is maintained by a(n) ___.
Venturi effect
The amount of gas drawn into the air stream in a low pressure gas system is controlled by the ___.
more flexible operation
Boilers are equipped with a combination gas/fuel oil burner for ___.
anthracite or bituminous coal
The underfeed stoker can burn ___.
in suspension and on grates
Spreader stokers burn coal ___.
under and over the fuel bed
To achieve complete combustion in a spreader stoker, air is introduced ___.
The thickness of the fuel bed on a chain grate stoker is regulated by a coal ___.
in suspension
Pulverized coal burns ___.
The volume of gas to the burner in a high pressure gas system is controlled by a ___ valve.
In order to burn 1 lb of fuel, approximately ___ lb of air are needed.
inches or tenths of an inch of a vertical water column
Draft is measured in ___.
atmosphere; inside the boiler setting
Draft in the boiler is measured between two points such as the ___ and ___.
greater than
Pressure at the discharge side of a forced draft fan is ___ atmospheric pressure.
economizers and air heaters
To reduce the heat loss of flue gases going to the chimney, boilers are equipped with ___.
move up while the air goes down
The convection air heater employs a counterflow principle in which the gases of combustion ___.
the use of bypass dampers
Both air and flue gas temperatures are controlled by ___.
condensation on the gas side of the air heater
If the temperature of air entering the heater gets too low, it will cause ___.
using soot blowers
Air heaters must be cleaned to ensure good heat transfer by ___.
have a fairly constant steam load
Air heaters can most successfully be used in plants that ___.
a loss of air for combustion and lower boiler efficiency
If air supplied for combustion mixes with gases of combustion, it could lead to ___.
inches of water
A diaphragm draft gauge is calibrated in ___.
power-driven fans
Mechanical draft is produced by the ___.
forced or induced
Mechanical draft can be classified as ___.
height of the chimney
The amount of draft available in a natural draft system is dependent on the ___.
outlet dampers
The gases of combustion leaving a boiler that has natural draft are controlled by ___.
between the boiler and the chimney
The induced draft fan is located ___.
fuel oil, coal, and gas
Mechanical draft is used when burning ___.
both forced and induced draft fans
Larger steam boilers that are equipped with air heaters and/or economizers must use ___.
increase the rate of combustion
When using mechanical draft, it is possible to ___.
Draft pressure maintained at a constant pressure is called a ___ draft system.
The oldest form of draft used in a boiler is ___ draft.
Solid particles created in the combustion process are called ___.
The temperature at which fuel oil will give off a vapor that will ignite readily when exposed to an open flame is its ___ point.
ultimate analysis is used
In order to determine the heating value of coal in Btu per pound, the ___.
The temperature at which fuel oil will give off a vapor that burns continuously is its ___ point.
degree of hardness
Rank refers to the ___ of the coal.
size, heating value, and ash content
Grade refers to the ___ of the coal.
moisture content, content of volatile matter, and fixed carbon and ash content
A proximate analysis of coal provides information regarding its ___.
elements present in the coal
An ultimate analysis of coal provides information regarding ___.
Bituminous coal has a high ___ content.
Anthracite coal has a high ___ content.
is lowered
When the temperature of fuel oil is raised, its viscosity ___.
The lowest temperature at which fuel oil will flow is its ___ point.
dangerous to use
Fuel oil with a low flash point would be ___.
___ coal is the type of coal most likely to have problems with spontaneous combustion when being stockpiled.
foam or dry chemical
A ___ fire extinguisher is the correct type to use on fuel oil fires.
Air that controls the rate of combustion is ___ air.
Air supplied to the burner that is more than the theoretical amount needed to burn fuel is ___ air.
___ combustion is when all fuel is burned using only the theoretical amount of air supplied.
___ combustion is when all the fuel is burned using the minimal amount of excess air.
formation of soot and smoke
Gases of combustion that cool on contact with the boiler heating surface before combustion is completed cause a(n) ___.
21; 79
Air needed for the combustion of fuel is made up of approximately ___% oxygen and ___% nitrogen.
Soot and smoke are the result of ___ combustion.
Carbon, sulfur, and hydrogen
___ is a combustible found in fuel.
complete combustion
Carbon dioxide (CO2) in the flue gas indicates ___.
incomplete combustion
Carbon monoxide (CO) in the flue gas indicates ___.
carbon dioxide, carbon monoxide, and oxygen
The Orsat gas analyzer measures the percentage of ___ in the flue gas.
complete, perfect, incomplete
___ is a type of combustion.
No. ___ fuel oil must be heated to reach the required temperature for combustion.
more Btu per gallon than
Higher numbered fuel oils produce ___ lower numbered fuel oils.
British thermal units
The heating value of a fuel is expressed in ___.
safe and efficient boiler operation
The primary function of a combustion control is to ensure ___.
small package, firetube, and watertube boilers
The ON/OFF control system is usually found on ___.
start and stop the burner on steam pressure demand
The purpose of the boiler pressure control found in the ON/OFF control system is to ___
highest part of the steam side of the boiler
the ON/OFF pressure control must be connected to the ___.
A steam siphon ensures that ___ does not enter the boiler pressure control.
in a vertical position
A mercury-tube pressure control will only be accurate when it is installed ___.
fuel supply; air supply; ratio of air to fuel; removal of combustion gases
The four elements that must be regulated in a combustion control system are ___.
set the operating steam pressure range of the boiler
The two scales found on the boiler pressure control are used to ___.
regulate the high and low firing rates of the burner
The purpose of the boiler modulating pressure control is to ___.
highest part of the steam side of the boiler
The modulating pressure control must be connected to the ___.
The blower motor control continues to operate after fuel is shut off the burner during ___.
control the burner firing cycle
The programmer in the ON/OFF control system is used to ___.
a prepurge period
To eliminate the danger of a furnace explosion during startup, the firing sequence must first allow for ___.
both the pilot and the main flame
The purpose of the scanner is to prove ___.
both the pilot and the main flame
The scanner must be installed on the front of the boiler to sight ___.
infrared or ultraviolet rays
The flame sensor is sensitive to ___.
secure the fuel, purge the firebox, and then shut down
In the event of a flame failure, the programmer will ___.
The positioning combustion control system used on older boilers cannot function without ___ pressure.
steam flow and pressure
The metering combustion control system is sensitive to changes in ___.
inlet damper, fan intake vanes, and the fan speed
Combustion air is controlled by ___.
induced draft fan
Gases of combustion are pulled from the boiler by the ___.
steam header pressure
The positioning combustion control system is sensitive to changes in the ___.
The most common type of pressure control used is the ___type.
square inch
Pressure gauges are calibrated in pounds per ___.
gauge pressure plus atmospheric pressure
Absolute pressure is equal to ___.
1 ½ to 2 times the safety valve setting
A boiler steam pressure gauge should have a range of ___.
highest part of the steam side
The boiler steam-pressure gauge must be connected to the ___of the boiler.
a siphon
The boiler steam-pressure gauge is protected from high temperatures by ___.
to take and read the readings for remote plants centrally
A primary reason for using thermocouples for measuring temperatures is ___.
mercury below
Vacuum gauges are calibrated in inches of ___atmospheric pressure.
degrees Fahrenheit
Most thermometers used in a steam plant are calibrated in ___.
Thermocouples measure ___.
superheated steam, gases of combustion, and condensate return
A ___ reading can be read using a thermocouple.
Liquids in a tank may be measured from a remote location using a ___.
a variety of fluids
Flow meters measure the rate of flow of ___.
venturi, orifice plate, and flow nozzle
The differential-pressure flow meter functions by receiving a difference of pressure across a(n) ___.
float in a tapered tube
The rotameter flow meter consists of a ___.
rotameter; valve
The types of variable-area flow meters are ___ and ___.
give an overall view of the steam plant operation
Recorders are used to ___.
smoke density
A Ringelmann chart is used to determine ___.
smoke density
Light and a photoelectric cell are sometimes used to indicate ___.
the boiler operator cannot always see the chimney to observe smoking conditions
Smoke indicators are often essential because ___.
promote safe and efficient operation
Modern steam plants use instrumentation to ___.
formation of scale, oxygen pitting, and carryover
Boiler water must be conditioned to prevent ___.
solids, gases, and other pollutants from industrial waste.
Natural water may contain ___.
caustic embrittlement
Boiler water having high alkalinity could develop ___.
Deposits of calcium and magnesium carbonates on the boiler heating surface cause ___.
caustic embrittlement
Cracking of the boiler metal along the seams and tube ends is caused by ___.
a nonadhering sludge
Chemicals added to the boiler water change the scale-forming salts into ___.
pitting of boiler metal
Oxygen in the boiler will cause ___.
Small amounts of water that leave the boiler with the steam is called ___.
scale formation on the tubes
A direct cause of overheating of the boiler tubes is ___.
Priming is dangerous and could lead to ___ hammer.
improper boiler water treatment
Scale buildup on the water side of a steam boiler is caused by ___.
heating the feedwater and using sodium sulfite
Oxygen present in the boiler water is removed by ___.
daily testing of boiler water
The frequency of blowing down a steam boiler is best ascertained by the ___.
ambient temperature
The cold lime-soda process softens the boiler water at ___.
continuous blowdowns
Closer control of boiler water chemical concentrations is maintained by ___.
cold lime-soda, hot lime-soda, and ion exchange
External feedwater treatment conditions the feedwater before it enters the boiler and can be a(n) ___ process.
the water level on all boilers that are on the line by blowing down the water column and gauge glass
When taking over a shift, the boiler operator must first check ___.
test the low water fuel cutoff control, inspect and check running auxiliaries for proper lubrication, and check the burner and the fire for correct flame, including the fuel temperature and pressure
The duties of a boiler operator taking over a shift are to ___.
by blowing down the low water fuel cutoff or allowing the water level in the boiler to drop
The low water fuel cutoff control can be tested ___.
hourly readings of all pertinent steam plant data
The operator in charge of a shift must maintain a boiler room log that indicates ___.
check for the correct boiler water level
Regardless of the type of fuel being used, before lighting off a boiler during a cold start-up, the operator must first ___.
a possible furnace explosion
The purpose of a flame failure control is to protect the boiler from ___.
purging the furnace
After establishing the proper boiler water level, the burner may be lit after ___.
warmed up slowly
In order to prevent uneven expansion of the boiler on a cold startup, the boiler must be ___.
During startup, the boiler vent should remain open until a pressure of approximately ___ psi is on the boiler.
75% to 85% of the line pressure
The automatic nonreturn valve on a boiler being cut in on a line should be opened when the steam pressure on the boiler reaches ___.
before the boiler is cut in on the line
It is good operating procedure to test the safety valve on an incoming boiler by hand ___.
closed as soon as
The free-blowing drain between the boiler's automatic nonreturn valve and the main steam stop valve should be ___ the boiler is cut in on the line.
slightly lower than
When cutting a boiler in on a line equipped with two hand-operated steam stop valves, the pressure on the boiler should be ___ line pressure.
keeping the superheater drain valve open until the boiler is cut in on the line
Boilers equipped with a superheater must be protected during warmup by ___.
Superheaters are prevented from overheating by the circulation of ___.
To ensure high heat transfer rates, ___ should be removed from boiler heating surfaces.
boiler vent
When the steam pressure in the boiler has dropped to 10 psi or 15 psi, the ___ should be opened.
As the boiler is cooling down, the boiler operator must maintain the ___.
cleaned on both the fire and water sides
To prepare a boiler for inspection, the boiler must be ___.
a hydrostatic test
After a boiler has had major repair work made on its steam or water side or has developed a low water condition, it should be subjected to ___.
flame scanner
Flame failure controls use a ___.
layed up either wet or dry
Boilers that are out of service for an extended period of time can be ___.
completely dry
If there is a danger of the boiler freezing, the boiler should be layed up ___.
chief engineer
Plant emergency procedures should be established by the ___.
warns the operator of high or low water
The whistle valve, which is located in the boiler water column, ___.
shuts off the fuel supply
A low water fuel cutoff ___.
thoroughly examined for signs of overheating
A boiler that has experienced a low water condition should be ___.
A high water level condition in the boiler can be corrected by using ___ blowdown.
either a flame failure or a low water condition
If a boiler that was on-line is down because of low steam pressure, the cause is ___.
1 ½ times the safety valve setting
When performing a hydrostatic test, the pressure on the boiler should be increased to ___.
an accumulation of combustible gases
A furnace explosion can be caused by ___.
The ASME code recommends that boilers be inspected internally and externally every ___.
confined space permit
Maintenance work performed inside a boiler requires a(n) ___ that contains procedures to prevent possible injury from hazards.
the immediate superior
When someone finds an unsafe condition in a plant, that person should report it to ___.
extend the life of the equipment, increase overall plant efficiency, and reduce downtime
Preventive maintenance of boiler room equipment can ___.
an alkaline detergent solution
New or retubed boilers should be cleaned with ___.
protect workers and equipment
The primary purpose of establishing a set of plant safety rules is to ___.
person involved
Reporting accidents is the responsibility of the ___.
fuel; heat; oxygen
The three ingredients needed to start a fire are ___, ___, and ___.
A fire caused by oil, gas, grease, or paint would be classified as a Class ___ fire.
Locations where painting or dipping is performed are examples of a(n) ___ hazard area.
once a shift
The low water fuel cutoff control should be blown down ___.