Gas Fundamentals

Question 1

At what point is primary air supplied to the combustion zone?

Answer 1

Upstream from point of combustion

Question 2

What does theoretical air consist of?

Answer 2

Primary and secondary air

Question 3

Excess air + theoretical air =

Answer 3

Total combustion air

Question 4

What is another name for calorific value?

Answer 4

Heating value

Question 5

Propane in a tank will build from liquid to vapour and expands _________ times its original volume?

Answer 5

270

Question 6

Standard temperature and pressure?

Answer 6

60 degrees F and 14.7 psia

Question 7

Three constituents of fire?

Answer 7

Heat, fuel and oxygen

Question 8

Incomplete combustion can produce harmful products, name 2?

Answer 8

Aldehydes and carbon monoxide

Question 9

Water vapour, carbon dioxide and nitrogen are produced when all fuel gas is burned and what takes place?

Answer 9

Complete combustion

Question 10

Appliance output divided by appliance input gives you?

Answer 10

Appliance efficiency

Question 11

When sizing combustion air and the input falls between 2 figures, what should you do on the chart?

Answer 11

Round up

Question 12

What is the difference between tight and loose construction?

Answer 12

Tight has vapour barrier, loose does not

Question 13

Where are combustion air terminals fastened?

Answer 13

To the appliance having the largest BTU input

Question 14

If height for grade cannot be adhered to, what can be installed?

Answer 14

A gooseneck

Question 15

Automatic dampers can be installed on combustion air, where will they be wired?

Answer 15

Interlocked to the main burner. In case of fail, the damper will be in the open position.

Question 16

What is added to gas from the transmission company to ensure safe handling? And at what rate is it added?

Answer 16

Mercaptan
1 lb/1,000,000 cubic feet

Question 17

Ambient air admitted to a venting system at a draft control device is known as what type of air?

Answer 17

Dilution air

Question 18

What temperature is water most dense?

Answer 18

4 degrees C or 39 degrees F

Question 19

Density x Volume =

Answer 19

Mass

Question 20

When water changes to steam, its volume increases approximately ________ times?

Answer 20

1700

Question 21

Fusion is the transformation from solid to ____________?

Answer 21

Liquid

Question 22

Condensation is the transformation from ___________ to liquid?

Answer 22

Gas

Question 23

In heat transfer, what type is through direct contact?

Answer 23

Conduction

Question 24

What type of heat transfer takes place because of differences in density?

Answer 24

Convection

Question 25

Transmission of heat energy by means of electromagnetic infrared rays is what type of heat transfer?

Answer 25

Radiation

Question 26

Substances expand and contract at different rate, what is this known as?

Answer 26

The coefficient of linear expansion

Question 27

According to the principles of hydrostatics, what will happen to the pressure on a horizontal pipe if the length of the pipe is increased?

Answer 27

Horizontal runs do not increase pressure so it will stay the same

Question 28

What is the heating value of Propane?

Answer 28

2500

Question 29

Propane cylinder may be filled to?

Answer 29

80% of the volume or 42% of the water capacity

Question 30

What is the minimum pressure rating for a propane cylinder?

Answer 30

240 psig

Question 31

Name 3 types of draft when referring to venting appliances

Answer 31

Forced, natural and induced

Question 32

How high must vents extend above a roof that is flat?

Answer 32

Minimum 3’ and 2' higher than any portion of a building within 10'

Question 33

Type B vent clearance to combustibles?

Answer 33

1"

Question 34

Type BW vent clearance to combustibles?

Answer 34

1/2"

Question 35

For each additional 90 degree change of direction over 2, how must the table be derated for draft hood appliances?

Answer 35

10% or derate by multiplying by .90

Question 36

What is a concern for venting a single mid efficient into a masonry chimney?

Answer 36

Condensation

Question 37

Where must a vent terminal be located in regards to a mechanical air supply?

Answer 37

Not within 6'

Question 38

What is ROT and what does it mean with respect to sizing vents?

Answer 38

Rule of Thumb sizing and it means to simply size the vent connector and common vent the same size as the draft hood or flue collar outlet

Question 39

All piping and equipment before and including the meter is the ownership of?

Answer 39

The utility company

Question 40

How many inches of water column is a low pressure natural gas line system?

Answer 40

7" to 14" WC

Question 41

Low pressure propane gas line system?

Answer 41

11" WC

Question 42

What is the smallest diameter of threaded pipe that can be used for natural gas unless it is schedule 80?

Answer 42

1/2"

Question 43

What type of gas line fitting cannot be nested?

Answer 43

Bushings

Question 44

When pipe protrudes through a ceiling or wall, how much pipe must be exposed? Through a floor?

Answer 44

Ceiling or wall-1" unthreaded pipe exposed Floor-2" unthreaded pipe exposed

Question 45

How deep must gas lines be buried in a commercial installation?

Answer 45

24"

Question 46

What is the first thing that must be determined prior to sizing a gas line?

Answer 46

Longest run (total furthest distance)

Question 47

Pressure taken in a gas line with only the pilot burning is what type of test?

Answer 47

Standing pressure test

Question 48

Pressure taken in a gas line with the appliances main burner operating is what type of test?

Answer 48

Operating pressure test

Question 49

What is the minimum size face on a test gauge?

Answer 49

3" in diameter

Question 50

Maximum working pressure of propane in a single family dwelling?

Answer 50

2 psig

Question 51

Gas law that states the pressure will increase, volume will decrease if the temperature remains constant?

Answer 51

Boyles Law

Question 52

Gas law that states if the temperature increases and the volume increases, the pressure will remain constant?

Answer 52

Charles Law

Question 53

Two ways of removing water from natural gas?

Answer 53

Adsorption and absorption

Question 54

Who is responsible for setting gas line pressures inside or outside of a building?

Answer 54

The installer

Question 55

Define matter?

Answer 55

Anything that has mass and occupies space

Question 56

What are 2 factors that affect the state in which matter exists?

Answer 56

Pressure and temperature

Question 57

What type of heat is the energy absorbed or released when a substance undergoes a phase change?

Answer 57

Latent heat

Question 58

When you say that liquid propane is lighter than water, you are referring to its?

Answer 58

Relative density

Question 59

What is used to allow a single wall vent connector to pass through a combustible wall or partition?

Answer 59

A ventilated metal thimble

Question 60

Clearance to combustibles for "C" vent?

Answer 60

6"

Question 61

When a chimney liner is used, how much must the tables be derated?

Answer 61

20%

Question 62

What type of venting is used on a high efficient oil burning appliance?

Answer 62

Type L

Question 63

What do you call support hangers for vertical pipe?

Answer 63

Riser clamps

Question 64

What is the function of pipe dope?

Answer 64

Lubricant

Question 65

What is the maximum volume of gas released from a vent? Natural gas Propane

Answer 65

Natural gas-2.5 cu.ft Propane-1cu.ft

Question 66

How are gaskets for grooved joints identified?

Answer 66

By color

Question 67

What can happen if a malleable iron fitting has been over tightened onto a carbon iron pipe?

Answer 67

Creeping

Question 68

What type of valve on a propane tank is used for liquid withdrawal?

Answer 68

Excess flow valve

Question 69

True or false- venting should be installed with no dips or sags?

Answer 69

True

Question 70

What type of pipe is never used for propane gas lines?

Answer 70

Polyethylene

Question 71

What is the psi and duration of time when pressure testing a rough in gas line over 200’?

Answer 71

15 psi for 1 hour

Question 72

Maximum number of supports that propane tanks are installed on above ground?

Answer 72

2

Question 73

A horizontal propane tank must have no more than ________ supports?

Answer 73

2

Question 74

What is the minimum schedule of pipe that can be used underground?

Answer 74

Schedule 40 but it must be welded

Question 75

What is the clearance for a propane tank up to 7800L and a masonry building with no openings?

Answer 75

10’ or 3m

Question 76

What is the minimum distance between a propane tank and an adjacent tank?

Answer 76

3’ or 1m

Question 77

How far off the floor does a furnace in a storage garage need to be?

Answer 77

18” or 450mm

Question 78

How far off the floor does a furnace in a repair garage need to be?

Answer 78

54” or 1400mm or 4.5’

Question 79

In what position, open or closed, will a gas valve fail in?

Answer 79

Closed