fans and boilers

Question 1

Which firetube boiler is built with a firebox that is not completely surrounded by water?

Answer 1

firebox boiler

Question 2

Which boiler consists of an arrangement of drums and headers interconnected by tubes?

Answer 2

watertube

Question 3

How many fans are used to control the draft through a balanced draft boiler?

Answer 3

two: one on the inlet and one on the outlet

Question 4

Which boiler would be classified as a firebox boiler?

Answer 4

HRT

Question 5

What is the minimum clearance required in front of an access panel on a gas-fired boiler?

Answer 5

24” regardless of whether it is insulated or not

Question 6

What does the installer have to do with the boiler and piping systems before turning them over to the owner?

Answer 6

Inspect and test for leak-tight service

Question 7

What is the cause of the most common problems encountered after start-up of steam boilers and systems?

Answer 7

improper cleaning and flushing

Question 8

What is likely to occur if there is a heavy concentration of dissolved or suspended particles in the boiler water?

Answer 8

The water may foam and could cause priming

Question 9

What should be done if the water in the sight glass is not clear after cleaning and flushing?

Answer 9

c) Repeat the cleaning procedure.

Question 10

What should be done with the results of all pertinent test results during the test, start and balance phases of a system start-up?

Answer 10

Record the results and have the results verified.

Question 11

Where is the appliance’s gross rating taken?

Answer 11

boiler nozzle outlet

Question 12

Where is the appliance’s net rating taken?

Answer 12

heat emission units

Question 13

What does the term pass in boiler terminology mean?

Answer 13

the number of times the products of combustion travel the length of the boiler

Question 14

What is the main advantage of steam over hydronic systems?

Answer 14

speed of transmission

Question 15

What is the usual maximum circulating speed of water for a low-temperature hot water heating system?

Answer 15

4 ft/sec

Question 16

What does load tracking refer to when discussing boilers?

Answer 16

the ability of a boiler to respond to changes in steam or hot water demand

Question 17

Which boiler has the ability to respond to sudden demands for large volumes of steam for a short period of time?

Answer 17

bent tube

Question 18

Which boiler has the ability to handle wide variations in load over a long period of time?

Answer 18

water tube

Question 19

Why is clean condensate considered to be ideal for feeding back into the boiler?

Answer 19

Condensate is essentially distilled water, so it contains no dissolved solids

Question 20

How often should a pop test be done on a safety valve used on an LP steam heating boiler?

Answer 20

b) annually

Question 21

What is the suggested method of determining whether water is flowing through a water feeder valve?

Answer 21

Listen with a stethoscope.

Question 22

What is the most probable cause of the water level in a gauge glass fluctuating rapidly?

Answer 22

foaming or priming inside the boiler

Question 23

What should be done if the pressure in a boiler rises higher than 20 psi during a capacity test on the safety valve?

Answer 23

A new valve must be installed that has sufficient capacity to pass the test.

Question 24

How often should the safety valve be tested on an LP steam heating boiler?

Answer 24

at least once for every 30 days the boiler is operating

Question 25

What is the most important thing to ensure when mounting a new glass into a water level gauge?

Answer 25

There should be no direct contact between the glass and the metal of the valve,

Question 26

what are the three purposes of a deaerator?

Answer 26

removes air from feed water uses steam and screens Pre heats feed water, better efficiency. Reservoir for feed water.

Question 27

If a boiler has shut down due to a low water condition, what should be done before allowing any water to be fed back into the boiler?

Answer 27

Allow the boiler to cool until the crown sheet of the boiler can be touched with the bare hand.

Question 28

What range of pH should be maintained in the water of an LP heating boiler?

Answer 28

7 to 9

Question 29

What is the main cause of foaming in a steam boiler?

Answer 29

Heavy concentrations of dissolved or suspended particles

Question 30

What are the three (3) types of air required for a space in which a boiler is to be Installed?

Answer 30

a) combustion air b) Ventilation air c) Dilution air

Question 31

What determines the type of boiler required in a system?

Answer 31

End use

Question 32

List the measurements used to generally net rate low-pressure boilers

Answer 32

a) BTU b) EDR

Question 33

List the measurements used to rate high-pressure boilers.

Answer 33

a) Boiler horsepower b) Lb of steam per hour c) MBH

Question 34

What devices are installed to control the direction of flow of flue gases through the watertube boiler?

Answer 34

baffles

Question 35

What are the three (3) most common configurations for the watertube type of package boiler?

Answer 35

a) A-type b) D-type c) O-type

Question 36

what is a Scotch marine boiler classified as a firetube or a firebox type of boiler?

Answer 36

firetube

Question 37

What are the two (2) names used to describe the appliances built under the ASME codes for boilers that do not use water or steam as the heat transfer medium?

Answer 37

a) vaporizers b) liquid heaters

Question 38

List three (3) kinds of pressure found in operating fan ducts.

Answer 38

a) static b) velocity c) total pressure

Question 39

What is a manometer used for?

Answer 39

A manometer is a U-shaped tube that is connected to the fan for measuring pressures

Question 40

How can you remove static electricity generated by fans?

Answer 40

Ground the rotating element with a ground brush and cable assembly

Question 41

Name the two (2) major types of fans according to flow through the impeller.

Answer 41

a) radial flow centrifugal b) axial flow propeller

Question 42

How can control of air through fans be accomplished?

Answer 42

inlet louvre, outlet dampers, varying the fan speed

Question 43

What is the purpose of a cold rollover of the fan rotor?

Answer 43

A cold rollover is used to confirm that there are no rubbing metal parts and no cracking noises experienced after a fan is overhauled.

Question 44

What is natural draft?

Answer 44

A draft caused naturally by heat difference or pressure different, no fans

Question 45

What is forced draft?

Answer 45

A draft created by a fan pushing air into the firebox, creating positive pressure throughout the boiler.

Question 46

What is induced draft?

Answer 46

A draft created by a fan in between the boiler and stack or chimney, creating a low pressure before it in the boiler.

Question 47

What is the purpose of nitrate testing?

Answer 47

To tell you how much salt is in the water, cloud instantly forms when engaged with salt. To much salt changes the heat and can lead to scale.

Question 48

What is a BTU?

Answer 48

British thermal unit it is a way to measure temp.The amount of energy needed to raise the temperature of 1 pound of water 1°F at STP is equal to 1 BTU/s

Question 49

What does the term atomizing mean?

Answer 49

Breaking the fuel to small amounts to mix better with air to get a better burn.

Question 50

What is the maximum circulating speed of water for a low temperature hot water heating system?

Answer 50

4ft/sec

Question 51

What is the purpose of a de-aerator?

Answer 51

? removes air from feed water uses steam and screens Pre heats feed water, better efficiency.

Question 52

how many more times space does steam occupy?

Answer 52

1600

Question 53

hydrostatic testing should never be done at more than what limit?

Answer 53

1 1/2 times boiler limit

Question 54

If too little air is supplied, heat loss will occur due to incomplete combustion, this is distinguished by what?

Answer 54

the thick black smoke that is coming out of the stack.

Question 55

If too much air is supplied, heat loss will occur because extra heat is going up the stack with the excess air, this is distinguished by what?

Answer 55

the white smoke that is coming out of the stack.

Question 56

Hunting or surging is most pronounced in what type of fan

Answer 56

axial

Question 57

hunting or surging is caused by what?

Answer 57

it is caused by the changing of air pressures as the fan cycles from high to low pressures.

Question 58

complete the sentence.... Total pressure is arrived at by

Answer 58

adding velocity pressure to static pressure.

Question 59

1 HP motor size generates about how many CFM of compressed air flow at about 90 PSI

Answer 59

3-4

Question 60

1inch of water produces how many psig?

Answer 60

.036 psig

Question 61

1 psig equals how many inches of water

Answer 61

27.7