Book 1 Chapter 1: Watertube Boilers

Question 1

One reason that low capacity watertube boilers are seldom used for low pressure heating is that they:
a) require less supervision
b) cost less
c) have the flue gas flowing inside the tubes
d) require more supervision for water treatment

Answer 1

D: require more supervision for water treatment

Question 2

The heating surface of a copper-tubular boiler consists of:
A) drums and headers
B) a continuous copper tube
C) straight firetubes
D) bent tubes attached to drums

Answer 2

B) a continuous copper tube

Question 3

The type of watertube boiler that has an upper drum and 2 lower drums is a(an) ___________ type.
A)”O”
B)”B”
C)”A”
D)”D”

Answer 3

C)”A”

Question 4

An advantage of a packaged boiler would be:
A) ease of installation
B) constructed entirely on site
C) it can be built to any height
D) no water treatment required

Answer 4

A) ease of installation

Question 5

The purpose of attaching “fins” to watertubes is to:
A) provide for a swirling action of the flue gases
B) increase the heating surface
C) increase the strength of the tubes
D) provide for better water circulation

Answer 5

B) increase the heating surface

Question 6

An advantage of a watertube boiler is:
A) It is custom built on site
B) It is only available with straight tubes
C) No steam space is required
D) It does not use softened water
E) A single supplier provides all components

Answer 6

E) A single supplier provides all components

Question 7

The combustion chamber of a serpentine tube watertube boiler:
A) Is located above the tube
B) Is enclosed by a non-insulated metal casing
C) Has inefficient heat transfer
D) is surrounded by the tube
E) Is located below the tubes

Answer 7

E) Is located below the tubes

Question 8

In comparison to a firetube boiler, a watertube boiler of the same capacity is:
A) Less destructive in the event of a pressure part failure
B) There is no difference between the two types of boilers
C) More destructive in the event of a furnace explosion
D) Less destructive in the event of a furnace explosion
E) More destructive in the event of a pressure part failure

Answer 8

A) Less destructive in the event of a pressure part failure

Question 9

A watertube boiler:
A) Tends to have higher stack temperatures
B) contains combustion gases within the tubes
C) Is a boiler consisting of tubes within a shell
D) Has tubes surrounded by water
E) Has tubes surrounded by combustion gases

Answer 9

E) Has tubes surrounded by combustion gases

Question 10

In comparison to a firetube boiler, a watertube boiler of the same capacity:
A) is less efficient
B) Is more expensive to construct
C) is less expensive to construct
D) Has little difference in expense or or efficiency
E) Is more efficient

Answer 10

B) Is more expensive to construct

Question 11

The upper drum of a packaged watertube steam boiler is referred to as the:
A) Blowoff drum
B) Pressure drum
C) Mud drum
D) Water drum
E) Steam drum

Answer 11

E) steam drum

Question 12

Boiler circulation is driven by:
A) water density difference
B) heat
C) tubing arrangement
D) formation of steam in the tubes
E) all of the above

Answer 12

E) all of the above

Question 13

In comparison to a firetube boiler, a watertube boiler of the same capacity:
A) is slow to generate steam pressure
B) can respond to load changes more quickly
C) there is no difference in steam generating capacity
D) contains more water
E) as a higher reserve steam capacity

Answer 13

B) Can respond to load changes more quickly

Question 14

In order to keep dissolved solids concentrations within safe limits the packaged tubular steam boiler utilizes a/an:
A) Water softener after the condensate receiver
B) Mixing chamber before the heating coil
C) Liquid flow control device
D) Automatic blowdown
E) Desalinator

Answer 14

D) Automatic blowdown

Question 15

A disadvantage of the watertube or tubular boiler is:
A) the foundation requirements due to mass
B) water treatment monitoring
C) it’s long warm-up period
D) it’s high maintenance cost
E) it’s thermal stresses

Answer 15

B) water treatment monitoring

Question 16

A watertube boiler is a boiler in which:
A) water passes through the tubes
B) air passes through the tubes
C) air passes around the tubes
D) water passes around the tubes
E) combustion gases pass through the tubes

Answer 16

A) water passes through the tubes

Question 17

A reason for preferring copper tubing in a tubular boiler is:
A) corrosion resistant
B) high metal expansion rate
C) elimination of feedwater treatment
D) ease of replacement of the tubes
E) low cost

Answer 17

A) corrosion resistant

Question 18

An advantage of a bent tube boiler is:
A) the tubes form baffles and furnace water walls
B) the boiler requires additional refractory
C) tubes are easily replaced compared to straight tube
D) it doesn’t require a pressure relief valve
E) only one drum is required

Answer 18

A) the tubes form baffles and furnace water walls

Question 19

The vent tube boiler design allows the tubes to create water walls that connect:
A) superheater
B) economiser
C) air pre-heater
D) upper and lower drums

Answer 19

D) upper and lower drums

Question 20

In a low pressure serpentine watertube boiler, the serpentine tubes are attached to upper and lower headers with _________ connections.
A) welded
B) pressure sealed
C) nozzle
D) seamless
E) threaded

Answer 20

E) threaded

Question 21

Three common types of bent tube watertube boilers are:
A) O, D, and E
B) B, O, and D
C) A, O, and D
D) B, D, and O
E) D, O, and L

Answer 21

C) A, O, and D

Question 22

Feedwater that is fed into the boiler to replace water that has been converted into steam is called:
A) Reused water
B) Condensate
C) Fresh water
D) Return water
E) Softened water

Answer 22

E) Softened water

Question 23

Boiler fireside baffles:
A) Are installed in large boiler furnaces only
B) Are installed in every boiler furnace
C) Are used with firetube boilers only
D) Will increase the stack temperature
E) Direct the flue gases through the boiler furnace

Answer 23

E) direct the flue gases through the boiler furnace

Question 24

The copper tube tubular boiler:
A) Can be gas or oil fired
B) Has the furnace in the upper sections
C) Is capable of very large capacities
D) is highly susceptible to corrosion
E) Has one part heating surface

Answer 24

A) Can be gas or oil fired

Question 25

Water circulation in the longitudinal drum boiler is created by:
A) Higher density feedwater
B) Direction of feedwater supply
C) Higher density boiler water
D) Lower density feedwater
E) The water circulation pump

Answer 25

A) Higher density feedwater

Question 26

The longitude drum boiler is a ______combustion gas pass boiler.
A) Four
B) Two
C) Three
D) Five
E) One

Answer 26

C) Three

Question 27

The tubes of a serpentine watertube boiler are connected to the upper and lower headers by:
A) Silver solder
B) Crosby clips
C) Welding
D) Four bolt flanges
E) Threaded connections

Answer 27

E) Threaded connections

Question 28

Which of the following are advantages of packaged watertube boilers?
1. Ease of installation
2. One supplier supplies all components
3. Built with all of the necessary fittings
4. Warranties and similar items are easy to deal with

A) 1, 2, 4
B) 1,2, 3, 4
C) 2, 3, 4
D) 3, 4
E) 1,2

Answer 28

B) 1,2,3, 4

Question 29

The combustion chamber of the serpentine watertube boiler is:
A) Stroker fired
B) Surrounded by the water tubes
C) Locted between the water tubes
D) Located below the water tubes
E) Downstream of the windbox

Answer 29

D) Located below the water tubes

Question 30

The “O” type boiler is constructed with ______ drums
A) One
B) Two
C) Three
D) Four
E) Five

Answer 30

B) Two

Question 31

The advantages of bent tube boilers include:
1. Bent tubes allowing for better heat transfer
2. Much refractory was eliminated
3. Limitations on design and configuration
4. The tubes could form flue gas baffles

A) 1, 2, 4
B) 2, 3, 4
C) 1, 2
D) 1, 2, 3, 4
E) 3, 4

Answer 31

A) 1, 2, 4

Question 32

The lower tubes of the serpentine watertube boiler are exposed to the ______ heat from the fire.
A) Convection and conduction
B) Conduction
C) Convection
D) Radiant and conduction
E) Radiant

Answer 32

E) Radiant

Question 33

The copper tubular boiler finds application in:
1. Residential hot water heating systems
2. Commercial hot water heating systems
3. Industrial hot water heating systems
4. Domestic hot water supply
5 High pressure steam production

A) 1,2,3,5
B) 3,4,5
C) 1,2,3
D) 1,2,4
E) 2,3,4

Answer 33

D) 1,2,4

Question 34

The ‘A’ type boiler is constructed with _______ drums.
A) Four
B) One
C) Two
D) Five
E) Three

Answer 34

E) Three