Download Ohio Boiler Test: Complete with Verified Answers and more Exams Engineering in PDF only on Docsity!
with Verified Answers.
The pressure at the base of a vertical foot of water is - Answer ✔️ 0.433 psi.
When performing a hydrostatic test, the pressure on the boiler should be
increased to - Answer ✔️ 1 ½ times the safety valve setting.
A boiler steam pressure gauge should have a range of - Answer ✔️ 1 ½ to 2
times the safety valve setting: The maximum size of the bottom blowdown line and the surface blowdown line
is - Answer ✔️ 2 1/2"
During startup, the boiler vent should remain open until a pressure of -
Answer ✔️ approximately 3 psiis on the boiler
Vacuum gauges are calibrated - Answer ✔️ in inches of mercury below
atmospheric pressure
The most common type of pressure control used is - Answer ✔️ the
Mercury-tube type.
A proximateanalysis of coal provides information regarding - Answer ✔️ its
moisture content, content of volatile matter, and fixed carbon and ash content.
with Verified Answers.
Higher numbered fuel oils produce - Answer ✔️ more Btu per gallon than
lower numbered fuel oils
Boilers are equipped with a combination gas/fuel oil burner for - Answer
✔️ more flexible operation
When steam is superheated it has - Answer ✔️ more heat energy, thus
producing more work. The convection air heater employs a counterflow principlein which the gases of
combustion - Answer ✔️ move up while the air goes down.
Bottom blowdown lines on a watertube boiler are located on - Answer
✔️ the mud drum.
The oldest form of draft used in a boiler - Answer ✔️ is natural draft
As the boiler is cooling down - Answer ✔️ the boiler operator must maintain
the NOWL
with Verified Answers.
Centrifugal feedwater pumps can be started with their discharge valves -
Answer ✔️ open or closed
When blowing down a boiler equipped with a quick-opening valve and a screw-
type valve - Answer ✔️ the quick-opening valve is opened first and closed
Main boiler stop valves must be - Answer ✔️ O's & Y gate valves.
The gases of combustion leaving a boiler that has natural draft are controlled by
- Answer ✔️ outlet dampers Water temperature that is too low in the open feed water heater could cause -
Answer ✔️ oxygen pitting in the boiler.
A surface condenser has - Answer ✔️ water passed through tubes to cause
steam to condense, causing a vacuum
Perfect combustion is - Answer ✔️ when all fuel is burned using only the
theoretical amount of air supplied.
Oxygen in the boiler will cause - Answer ✔️ pitting of boiler metal
with Verified Answers.
The ASME code recommends that boilers be inspected internally and externally -
Answer ✔️ every year(annually)
Liquids in a tank may be measured from a remote location using - Answer
✔️ a pneumercator.
Safety valves are designed to - Answer ✔️ pop open
A turbine feed water pump differs from a centrifugal feed waterpump in that it a
- Answer ✔️ positive displacement pump The blower motor control continues to operate after fuel is shut off the burner
during - Answer ✔️ post purging
The relieving capacity of a safety valve is measured in - Answer ✔️ pounds
of steam per hour capable of discharging under a given pressure
A steam pressure gauge is calibrated in - Answer ✔️ pounds per square inch
The lowest temperature at which fuel oil will flow is - Answer ✔️ pour point
with Verified Answers.
The main purpose of a water column is to - Answer ✔️ reduce turbulence in
the gauge glass to get a more accurate reading of the water level in the boiler.
The vacuum on the exhaust side of the turbine - Answer ✔️ reduces back
pressure and steam flow rate
The purpose of the boiler modulating pressure control is to - Answer
✔️ regulate the high and low firing rates of the burner.
A line desuper heater is typically used - Answer ✔️ when both superheated
and saturated steam are needed, with a pressure-reducing station, and with feed water addition to desuper heat the steam.
Soot should be - Answer ✔️ removed from boiler tubes for better heat
transfer.
The types of variable-area flow meters are - Answer ✔️ rotameter and
valve.
In a pressure atomizing burner, atomization is accomplished by - Answer
✔️ rotating, high pressure oil coming out of the plug or sprayer plate
with Verified Answers.
The primary function of a combustion control is to - Answer ✔️ safe and
efficient boiler operation.
Boiler fittings are necessary for - Answer ✔️ safety and efficiency
To protect the turbine pump from excessive pressure, a(n) - Answer
✔️ .safety relief valve must be installed on the discharge line.
To prevent failure from pressure over the MAWP, - Answer ✔️ all steam
boilers must be equipped with at least one safety valve.
The most important fitting on a boiler is - Answer ✔️ the safety valve
Any repairs to a safety valve should be done by - Answer ✔️ the safety valve
manufacturer or manufacturer's authorized representative. Deposits of calcium and magnesium carbonates on the boiler heating surface
cause - Answer ✔️ scale
with Verified Answers.
When cutting a boiler in on a line equipped with two hand-operated steam stop
valves, the pressure on the boiler should be - Answer ✔️ 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 -
Answer ✔️ slightly lower than line pressure.
Maximum allowable Working pressure - Answer ✔️ MAWP
The ON/OFF control system is usually found - Answer ✔️ small package, fire
tube, and water tube boilers.
Light and a photoelectric cell are sometimes used to indicate - Answer
✔️ smoke density
A Ringelmann chart is used to determine - Answer ✔️ smoke density
Natural water may contain - Answer ✔️ solids, gases, and other pollutants
from industrial waste
with Verified Answers.
To ensure high heat transfer rates, what should be removed from boiler heating
surfaces. - Answer ✔️ soot
Pressure gauges are calibrated in - Answer ✔️ pounds per square inch.
The steam and water drum of water tube boilers is dished (concave) to -
Answer ✔️ to eliminate the need for stays.
A steam siphon ensures that - Answer ✔️ steam does not enter the boiler
pressure control.
Super heaters are prevented from overheating by - Answer ✔️ the
circulation of steam.
The metering combustion control system is sensitive to changes in - Answer
✔️ steam flow and pressure
The positioning combustion control system is sensitive to changes in -
Answer ✔️ the steam header pressure
with Verified Answers.
Boiler plates and stay bolts are subjected to - Answer ✔️ tensile stress.
The duties of a boiler operator taking over a shift are to - Answer ✔️ 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.
Smoke indicators are often essential because - Answer ✔️ the boiler
operator cannot always see the chimney to observe smoking conditions. Water temperature that is too high in the open feed water heater could cause -
Answer ✔️ the feed water pump to become steam bound.
When someone finds an unsafe condition in a plant, that person should report it
to - Answer ✔️ the immediate superior
Both air and flue gas temperatures are controlled by - Answer ✔️ the use of
bypass dampers
with Verified Answers.
When taking over a shift, the boiler operator must first check - Answer
✔️ the water level on all boilers that are on the line by blowing down the water
column and gauge glass.
The boiler vent is open when warming up a boiler until - Answer ✔️ there is
10 to 15 psi of steam pressure on the boiler. The comparison, or ratio, of heat supplied in fuel to heat absorbed by water is
defined - Answer ✔️ as thermal efficiency.
A boiler that has experienced a low water condition should be - Answer
✔️ thoroughly examined for signs of overheating.
In a fire tube boiler, the heat and gases of combustion - Answer ✔️ pass
through the tubes A primary reason for using thermocouples for measuring temperatures is -
Answer ✔️ to take and read the readings for remote plants centrally.
Water from an open deaerating feed water heater - Answer ✔️ flows to the
feed water pump
with Verified Answers.
The amount of gas drawn into the air stream in a low pressure gas system is
controlled by - Answer ✔️ the Venturi effect.
The differential-pressure flow meter functions by - Answer ✔️ receiving a
difference of pressure across a(n) venturi, orifice plate, and flow nozzle.
Bituminous coal has a - Answer ✔️ high volatile content.
On a boiler burning low pressure gas, the volume (amount) of gas burned is
controlled by - Answer ✔️ the volume of air passing through the venturi
tube
To prevent caking and to dry the coal entering the pulverizer, - Answer
✔️ warm air is used
In order to prevent uneven expansion of the boiler on a cold startup, the boiler
must be - Answer ✔️ warmed up slowly
A whistle valve is used to - Answer ✔️ warn the operator of high or low
water.
with Verified Answers.
ASME - Answer ✔️ American Society of Mechanical Engineers
Priming is dangerous and could lead to - Answer ✔️ water hammer
The mud drum is the lowest part of the water side of - Answer ✔️ a water
tube boiler
The water tube boiler was developed - Answer ✔️ to provide steam at
higher pressures
Soot blowers are mainly found on - Answer ✔️ water tube boilers
To increase the life of a furnace refractory - Answer ✔️ some watertube
boilers are equipped with waterwalls
A line desuper heater is typically used - Answer ✔️ when both superheated
and saturated steam are needed, with a pressure-reducing station, and with feed water addition to desuper heat the steam.
water wall - Answer ✔️ a furnace or other wall within a boiler enclosure
that is composed of numerous closely set water-tubes. These tubes may be either bare, or covered by a mineral cement.
with Verified Answers.
Needed for the combustion of fuel is made up of approximately - Answer
✔️ 21% oxygen and 79 % nitrogen
The automatic non return valve on a boiler being cut in on a line should be
opened when the steam pressure on the boiler reaches - Answer ✔️ 75% to
85% of the line pressure
. A sudden drop in boiler steam pressure without a corresponding drop in boiler
water temperature could result - Answer ✔️ in a boiler explosion.
Super heater tubes are protected from warping or burning out by - Answer
✔️ a continuous flow of steam.
Because of the large volume of water, the boiler most likely to cause a boiler
explosion - Answer ✔️ a fire tube boiler.
Stays and braces are needed to prevent bulging in - Answer ✔️ a fire tube
boiler (high or low pressure).
with Verified Answers.
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 - Answer ✔️ a
hydrostatic test
An indication of a dirty fuel oil strainer would be - Answer ✔️ a large
pressure drop across the strainer If air supplied for combustion mixes with gases of combustion, it could lead to -
Answer ✔️ a loss of air for combustion and lower boiler efficiency.
Chemicals added to the boiler water change the scale-forming salts into -
Answer ✔️ a non-adhering sludge
The purpose of a flame failure control is to protect the boiler - Answer ✔️ a
possible furnace explosion To eliminate the danger of a furnace explosion during startup, the firing
sequence must first allow for - Answer ✔️ a pre purge period.
A secondary means of determining water level in a boiler are - Answer
✔️ try cocks
