CHAPTER 8 (BOILER) Flashcards
Which of the following is necessary to generate steam in a boiler?
all of the above
It is the part of the boiler with water on one side and heat on the other side.
heating surface
A ______ boiler has heat and gases of combustion that pass through tubes surrounded by water
fire tube
A _____ boiler has water in the tubes and heat gases of combustion passing around the tubes
water tube
Which of the following are used in boilers to direct the gases of combustion over the boiler heating surface?
Baffles
The three-basic type of low pressure heating boilers are ____, _____, and _____.
fire-tube; water tube; cast iron sectional
In a low pressure gas system, the gas regulator reduces that city gas pressure to ___ psi.
0
In the ____ air mixes with the fuel and burns.
combustion chamber
The function of the steam boiler is to ________.
produce steam
Which of the following is the most common type of water tube boiler?
straight-tube multiple pass
Excess fuel oil in the fuel oil system returns to the:
fuel oil tank
It is the system that provides the air necessary for combustion.
draft
The gases of combustion leave the boiler through the:
breeching
Which of the following boiler does not use tubes?
cast iron sectional
Which of the following will make a boiler work more efficiently?
the heating surface is increased
What are the four systems necessary to operate boiler?
feedwater; fuel; draft; steam
The _____ forms a vacuum that draws out of the condensate return line and into the vacuum tank.
vacuum pump
Which of the following can be a function of the container in a boiler?
all of the above
At what temperature will water normally turns to steam?
212°F
Which of the following statements is true for cast iron sectional boilers?
none of the above
Which of the following is the most important valve on a boiler?
safety valve
The MAWP on a low pressure steam boiler is ____ psi.
15
Which of the following best defines a total force acting on a boiler?
area times pressure
The ASME code states that boiler with over ____ square feet heating surface must have two or more safety valve.
500
The area of a safety valve 4” in diameter is how many square inches.
12.5664
Which of the following is the only valve permitted between safety valve and the boiler?
no valves are permitted between the boiler and safety valve
The range of the pressure gauge should be ____ times the MAWP of the boiler.
1 1/2 to 2
The ASME code only allows ____ safety valve on boiler.
spring-loaded pop-type
How much is the total force on a safety valve 2 1/2 in diameter and with a steam pressure of 15 psi?
73.63125
The steam pressure gauge on the boiler is callibeated to read in:
pounds per square inch
Live steam is prevented from entering the Bourdon tube of the pressure gauge by which of the following?
siphon
What pressure gauge that can read whether vacuum pressure or not?
compound
Which of the following best defines a vacuum?
a pressure below atmospheric
Safety valves are designed to pop open and stay until there is a ___ psi drop in pressure.
2 to 4
What type of boiler that uses safety valve?
all of the above
The water is located at the NOWL so the lowest visible part of the gauge glass is ____ above the highest surface.
2” to 3”
Blowback of a safety valve is to prevent:
chattering
The boiler bottom blowdown line should discharge to a(n) _____.
blowdown tank
If the desired cut-in pressure of the boiler is 6 psi and the desired cut-out pressure is 10 psi, the differential pressure setting must be ___ psi.
4
Impurities that build up on the surface of the water in the boiler prevent ____ from breaking through the surface of the water.
steam
To prevent air pressure from building up in the boiler when filling the boiler with water, the ____ must be open.
boiler vent
The operating range of the boiler is controlled by:
pressure control
The ______ regulates the high and low fire of the burner
modulating pressure control
The best time to blow down the boiler to remove sludge and sediments is when boiler is at:
its lightest load
The level of the water in the ____ indicates the water level in the boiler.
gauge glass
When blowing down a boiler, the quick- opening valve should always be opened ____ and closed _____.
first, last
Which of the following is added to boiler so that water changes scale-forming salts into a non adhering sludge?
Chemicals
A ______ valve is installed before the ____ to allow the stean pressure gauge to be changed if malfunction occurs.
gate, siphon
What pressure gauge that reads more pressure than is actually in the boiler?
fast
According to ASME code, safett valves on low pressure should be tested by hand atleast
once a month
According to ASME code, safett valves on low pressure should be tested by hand atleast
once a month
The purpose of safety valve is prevent pressure in the boiler from:
exceeding its MAWP
The term applied when a safety valve opens and closes rapidly
Chattering
The safety valve on low pressure boiler opens when pressure in the boiler exceeds how many psi?
15
After the total force of the steam has lifted the safety valve off its seat, the steam enters the _____
huddling chamber
Wgat causes false water level readings in the gauge glass?
Foaming
Fusible plugs are required on ____ boilers by the ASME code
all of the above
On a pressure control, ____ pressure plus ____ pressure equals ____ pressure
cut in; differential ; cut in
On a pressure control, ____ pressure plus ____ pressure equals ____ pressure
cut in; differential ; cut in
A burner should always start up in ___ fire and shut down in ___ fire.
low, low
The water in the boiler is heated, turns to steam, and leaves the boiler through the:
main steam line
When steam gives up its heat in a heat exchanger it turns to:
condensate
A ____ pump discharges the return water back to the boiler
vacuum
How do you call a valve thaht controls the flow of water in one direction only?
check
The feedwater ___valve should be located as close to the shell of the boiler as practical
stop
A ____ after each radiator allows ___ to pass through to the return line
steam trap; condensate
A ____ valve should be located between boiler and the valve on the feedwater line
stop; check
The feedwater ____ valve opens and closes automatically
check
The vacuum pump pumps water and discharges air to the :
atmosphere
The range of pressure on vacuum switch is usually:
2” to 8”
Top test the vacuum pump, the operator puts the selector switch in the ___ position
continuous
Water added to the boiler to replace water lost due to leaks and blowing down is known as ___ water
make up
Excessive use of cold city water makeup reduces ovevrall efficiency because the water must be ____ before use in the boiler
heated
The vacuum pump selector switch is normally in the position during the heating season
float or vacuum
The ___ shuts off the burner in the event of low water
low water fuel cut-off
Water is supplied to the condensate return tank by the ___ pump
vacuum
The feedwater regualtor is located at the ____ and is connected to the boiler in the same manner as the ___
NOWL; water column
What maintains a constant water level in boiler?
feedwater regulator
The low water fuel cut off should be tested:
daily
The burner should be ____ when the low water cut off is blow down
firing
Which of the following valve must be used as boiler main steam stop valve?
os&y gate
