UTB9 Boilers Flashcards
At what temperature Fahrenheit does water reach the boiling point?
212°
What is the melting point of a fire-actuated fusible plug filled with an alloy of tin, copper, and lead?
445°F to 450°F
The bottom of the inverted bell of the liquid sealed draft gauge is sealed with which substance?
oil or mercury
Which method is used to clean out a boiler fouled with grease?
Boiling out
What color should the pull chain handle be painted for the center gauge cock?
Green
An increase in pressure results in what effect on the boiling point temperature of water?
Increase
What is the difference between dry saturated steam and wet statured steam?
Absence of water particles in suspension
Which description identifies a water-tube boiler?
Products of combustion surround the tubes through which the water flows.
In a water-tube boiler, how are baffles usually arranged?
Directly across the tubes three times prior to being discharged from the
boiler.
Which is NOT a type of fire-tube boiler? A. Horizontal supply tubular B. Firebox C. Scotch marine D. Vertical tube
A. Horizontal supply tubular
Which safety device provides added protection against low-water conditions?
Fusible plugs
Which type of fire-tube boiler are UTs assigned to operate and maintain more often than any other type?
Horizontal fire-tube
Where is the blowdown pipe of a vertical tube boiler attached on the water leg?
Lowest part
Gas flows into the horizontal return tubular boiler from what component?
Firebox to rear of boiler
Where are the manholes located on a horizontal return tubular boiler?
Upper part of shell
What is the position of the air cock prior to firing a cold boiler with no steam pressure?
Open
Which piece of equipment facilitates the removal of gases through the stack?
Induced draft fan
Which blowdown valve permits the removal of scale and sediments from the water column?
Water column blowdown
The fire-actuated plug has a melting point of how many degrees Fahrenheit?
445°F to 450°F
Which equipment steadies the water level in the gauge glass through the reservoir capacity of the column?
Water column
What are the three lengths associated with the electrode assembly?
High, Low, and Burner cutout
What is the purpose of try cocks?
To prove the water level in the boiler
How many safety valves are required on a boiler that has more than 500 square feet of heating surface?
2
What device on the safety valve is provided to lift the valve from its seat?
Lifting lever
A steam injector can lift a stream of water at a temperature of 120°F how many feet?
14 feet
(True or False) The water supply should not be hotter than 120°F for the injector to operate.
True
What is known as the process of maintaining a difference of pressure between two points in a system?
Pressure regulating
Which is NOT a function of the pressure control?
A. To control the pressure in the boiler.
B. To secure water flow when temperature reaches 500°F.
C. To secure the fuel burning equipment when the pressure reaches a
predetermined cutout.
D. To start fuel burning equipment when the pressure drops to the cut-in
point.
B. To secure water flow when temperature reaches 500°F.
What are the two settings on the pressure control?
Cut-in point and differential
Which method is used to controlling combustion air?
Manually adjusted air damper
What is the only means of obtaining the correct ratio of fuel to air?
Setting of air damper
In combustion control, what is the normal atomizing pressures in pounds per square inch?
95 and 120 pounds per square inch
How many seconds after flame failure will the burner equipment be secured?
4
Safety shutdown sequence will commence after how many seconds after pilot flame is not established and confirmed?
7
Which meter is used as a guide in controlling the relationship between air required and air actually supplied to burn the fuel?
Combustion air and steam flowmeter
What unit of measurement is associated with draft gauges?
Inches of water
Which are scale-forming elements?
Precipitates of hardness and silica
What type of coating does silica leave behind when it precipitates in boiler feedwater?
Hard glossy
What is the most widely used method of treatment of scale?
Alkaline phosphate-tannin
Boilers operating at what pressure are normally used for hot-water generation?
15 psi or less
Which reagent is NOT used in the test for hardness? A. Hardness indicator B. Hardness buffer C. Hardness filter D. Hardness titrating solution
C. Hardness filter
What function does carbon play in the test for phosphates?
Absorbs the tannin
Concentrated stannous chloride should be discarded after how many months after preparation?
2
At what temperature, in degrees Farhenheit, should the boiler water sample be for the conduct of the caustic alkalinity without tannin test?
70
At what temperature, in degrees Fahrenheit, should the boiler water sample be for the conduct of the caustic alkalinity with tannin test?
160
Prior to conducting the sodium sulfite test, to what temperature, in degrees Fahrenheit, should the boiler water sample be cooled?
70
When the paper turns orange in the conduct of the pH test, what does this indicate to the operator?
pH is too low
(True or False) The lower the concentration of ionizable salts, the greater the conductance of the sample.
False
Which cleaning method for fire-side boilers is NOT recommended? A. Scraper cleaning B. Wet steam sweating C. Dry steam lancing D. Hot-water washing
C. Dry steam lancing
When utilizing the hot-water washing method, at what temperature, in degrees Fahrenheit, should the water be?
150
How is fireside slag removed from the convection super heaters?
By circulating cold water through the tubes.
How is water corrosion reduced?
Maintaining the boiler water alkalinity at proper levels.
After a safe shutdown of the boiler, what is required prior to commencing tube cleaning?
Adequate ventilation
(True or False) The lower ends of all tubes must be cleaned from the water drum or header.
True
Which acid is NOT required in chemical cleaning of boilers? A. Boric B. Sulfuric C. Citric D. Sulfamic
A. Boric
What is the purpose of citric acid?
Removal of boiler waterside deposits.
What are the two methods of boiler acid treatments?
Circulation or fill-and-soak
Which is NOT a neutralizing solution? A. Soda ash B. Trisodium phosphate C. Sodium tripolyphosphate D. Calcium sulfate
D. Calcium sulfate
When conducting the boiling out method, the temperature of the water in the boiler needs to be at what degree Fahrenheit for at least 24 to 48 hours?
200
What is the most common cause of major boiler damage?
Low water
How often are blowdown valves opened?
Once daily
How often are steam traps tested for correct operation?
Once a month
The clearance between the shoulder of a manhole plate and the manhole must not exceed what value?
1/16 inch
How often is a hydrostatic test performed on a boiler?
Annually
In a hydrostatic test, what is the minimum water temperature of the boiler, in degrees Fahrenheit?
70
On boilers where the superheated steam reaches 850°F or higher, what material is the super heater tubes constructed out of?
Carbonmolybdenum steel
What tool is used to remove tubes?
Air-powered side-cutting chisel
Tubes of 2 inches outside diameter are belled to what minimum distance, in inches?
1/8 but no more than 3/16
What is the maximum projection into the drum or header for tubes of 2 inches outside diameter?
7/16 max
5/16 minimum
After the repair of boiler refractories, how many hours must the wall dry with the burner shutters open?
12
Plastic requires a baking-out temperature range of what value, in degrees Fahrenheit?
2900°F to 3000°F
When should the head gasket be inspected?
Whenever both front and rear doors are opened.
How many phases of operation are associated with boiler operation?
7
Pre-operating checks are performed at what time of boiler operation?
Before lining up and lighting off
During normal operation of the boiler, how many responsibilities does the operator have?
2
maintain proper water level at all times
prevent loss of ignition when burning fuel is in suspension
At what temperature, in degrees Fahrenheit, should the flue-gas temperature be above the steam-produced temperature?
150
How many inches of water should the draft be under normal operating conditions?
0.03 to 0.06
When should the drum vent valve be opened during normal operations?
Drum pressure drops to 25 psig
At what temperature, in degrees Fahrenheit, can the boiler be emptied?
Below 200
How many emergency situations should the operator be aware of when running a boiler?
6
(1) low water
(2) high water
(3) serious tube failure
(4) flarebacks
(5) minor tube failure
(6) broken gauge glass
The boiler operating log is set up on what frequency for logkeeping?
24-hour period divided into three 8-hour shifts
OR
24-hour period divided into four 6-hour shifts
At shore installations, the handles on pull chains to boiler water gauge cocks are colored; which color is associated with opening water-gauge glass stop valve?
WHITE
At shore installations, the handles on pull chains to boiler water gauge cocks are colored; which color is associated with closing water-gauge glass stop valve?
RED
At shore installations, the handles on pull chains to boiler water gauge cocks are colored; which color is associated with the top gauge cock?
YELLOW
At shore installations, the handles on pull chains to boiler water gauge cocks are colored; which color is associated with the bottom gauge cock?
BLUE
What device is used to hold a switch lever in the off position?
Lockout