Boiler Flashcards
At 0 pasig, How many BTUs are necessary to change 1 pound of water at 212° in the 1 pound of steam
970
Radiation is a form of heat transferred by
Waves
Steam at 100 psi and 400°F is
Super heated
Which of the following most closely define sensible heat
Heat quantity above the point of saturation
What is required to raise the temperature of 1 pound of water at 32° to 212°F
180 btu. 212-32=180
Increasing the pressure has what effect on the boiling point of water
Temperature will rise
Heat absorbed by water when it changes from a liquid to steam at the boiling point is called
Latent heat
Heat may be transferred in how many ways
3
A boiler horsepower is defined as
Evaporation of 34.5 pound of water from And at 2 12°F per hour
A boiler steam pressure gauge reads 150 what is the absolute pressure
Absolute pressure is 164.7. 150 PSIG +14.7 atmospheric pressure
What does 212°F equal on the Celsius scale
100
One boiler horsepower is equal to how many BTUs
33,472
A British thermal unit is
The amount of heat needed to raise 1 pound of water 1°F
Hydronic heat is
Hot water heat
Superheated steam is
Reheated steam
2545 BTUH represents
One horse power hour
A throttling calorimeter is used to measure the quality of
Saturated steam
The amount of heat and 1 pound of saturated steam is approximately equal to
1150 BTU
A boiler operating 100 psi as a saturated steam temperature 338°F what is the boilers water
338Degrees Fahrenheit
Heat dry pipe is used to
Separate moisture from steam as it leaves the drum
The purpose of a staybolt is to
Strengthen and support flat plates on the fire tube boiler
The boiler vent valve is located on
The top of the steam drum
The purpose of the hole in the end of the stay bolt is to
Indicate that the stay bolt is cracked or broken
A fusible plug melts
450°F
As the fire rating increases in a boiler equipped with a convection superheater The steam temperature
Increases
When boilers are connected to a common header it it required than ample free Blowing drain be provided between the stop Valves if either or both boilers have
Manholes
It is permissible to have only one bottom blowdown valve on the boiler When
When the mawp Does not exceed 100 psi
When the boiler pressure exceeds 125 psi is required
Extra heavy duty pipe be used on the blowoff system
Baffles our place between the tubes of a Boiler for the purpose of
Directing the travel of fluegases
A boiler has a steaming capacity of 35,500 pounds of steam for our the evaporation rate is 10 pounds per foot squared of heating service per hour what is the horsepower rating at the border
1000
Boiler tube sizes are specified by
Outside diameter
The maximum size of boiler blowdown lines valves and fittings you’re not exceed
2 1/2 inches
The purpose of an expansion tank in hot water heating system is to provide for the
Expansion of Water
Heavy accumulation of soot in a boiler will result in
Loss of boiler efficiency
How are the tube secured in a fire tube boiler
Rolled and beaded over
A tube in a fire tube boiler is surrounded
Water
Atmospheric pressure is considered to be at
14.7 PSIA
In a water tube boiler flue What surrounds the tubes
Fluegases
Diagonal stays are found in
Firetube boilers
Hand holes in manholes are oval
For the removal from the pressure vessel
Check the water level level in the gauge glass of steam boiler use the
Trycocks
The vent valve does what
Removed air during warm up and prevents a vacuum from Forming during cool down
A high-pressure boiler has it safety valve set at
Above 15 psi
What is it an advantage of a fire boiler over of a water tube boiler
Lower initial cost
Water walls are found
In a water tube boiler furnace
The best time to bottom blow down the boiler is
Low load under full pressure
A telltale Hole is found in a
Staybolt
A 2 inch boiler tube has a wall thickness of 3/16 of an inch what is the inside diameter
One and five eights inches
At what temperature does steel start rapidly lose its strength
700°F
A hot water heating system is about to be started how full of water should expansion tank gauge class
1/3
What is the relationship between longitudinal stress and circumferential stress
Longitudinal stress is twice the circumferential stress
A therm is equal to how many BTU
100,000
The factor of evaporation is
Heat added the boiler divided by 970.3
The purpose of a bottom blow down is
Remove sledge and sediment
Superheaters raise the temperature of
Steam
The heating surface of a boiler is the
Exposed to the flame and fluegases
The purpose of a super heater is
To heat steam above its
saturation temperature
What is the formula for the factor of evaporation
H-b/970.3 btu
What can cause a super heater to overheat
Dirty tubes
A boiler has a steam in capacity of 34,500 pounds of steam per hour. The evaporation rate is 10 pounds per foot squared of heating service per hour. What is a boiler heating surface
3450
How many square feet of heating surfaced as a 3 inch fire tube 20 foot long with 3/16 inch inch wall have
13.7
In a high temp hot water boiler what causes a tube to overheat
Poor circulation or plugged tube
Where is a downcomer found
A water tube boiler
Extreme fire box temperature changes causes
Spalling
The low water cut off does what
Shut off the burner when the boiler is low on water
Steam coming from the bottom try cock would indicate what
Low water level
Which type of valve has the most resistance to flow
Globe
When checking the water level of the boiler do what
Blow down the gauge glass and water column
A siphon or pigtail is used to protect a steam pressure gauge from
Steam Temperature
The feed water water regulator is located
At the normal operating water level
And automated feed water regulator does
Insurers the proper water level in the boiler
To test the low-water cut off
The burner must be fired
The purpose of testing a safety valve by hand is to
Make sure the valve can lift
The automatic control that protect the boiler from being dry fired is
Low water cut off
On a steam boiler testing the operation of the safety valve by hand with the boiler under pressure should be done how often
Monthly
What type of valve has the least resistance to flow
Gate
The gauge glass shows full while the middle try cock shows steam. When blow down the gauge glass refills. What is the probable cause
The top gauge glass connection is blocked
The purpose of a bowl at the bottom of the water column is to
Serve as a sediment chamber
When checking a safety valve with a hand lifting gear the pressure should be no lower than
75% of the safety valve set pressure
If valves are located between the boiler and water column they must be what
Locked or sealed open
When A hydrostatic test is put on a boiler each safety valve should be
Held to its seat by the means of a testing clamp
After installing a new gauge glass the proper procedure for returning the glass to service is to
Open the drain and crack the top valve open
The steam pressure gauge is graduated in
Pounds per square inch
One of the purposes of the water column is to
Dampen the oscillation of the water in the gauge glass
The gauge glass should be blown down
Daily
The flame failure control is tested by
Securing
the fuel supply to the burner
An aquastat
Controls operation to the changes in temperature
The pressure sensitive device attached to the van housing have a fully automatic burner starts operating when there is a
Fan failure
If the pressuretrol starts the burner and ignition fails to take place the controller that protects the
Flame failure cut off
The pressure sensitive eyes is sometimes called a what
Vaporstat
Draft is measured
Inches of water
Which of the following is used to measure temperature
Pyrometer
The main stop valve is located on the
Steamline
OS&Y stands for
Outside screw and yolk
