Chapter C

Question 1

What are the four types of gas?

Answer 1

Wet gas, dry gas, sour gas, and sweet gas.

Question 2

What is wet gas?

Answer 2

Propane, butane, pentane, hexane, and heptane. Propane and butane are also known as LP - gases.

Question 3

What is dry gas?

Answer 3

It’s also known as processed natural gas, and is stored in underground storage tanks for use as a fuel gas.

Question 4

What is sour gas?

Answer 4

Gas containing a high percentage of hydrogen sulphide.

Question 5

What is sweet gas?

Answer 5

Natural gas with little or no hydrogen sulphide content.

Question 6

What is the name of the chemical grouping of petroleum gases?

Answer 6

Hydrocarbons.

Question 7

Name the three most used petroleum gases.

Answer 7

Natural gas, propane, and butane.

Question 8

What are the main components of natural gas?

Answer 8

Methane and ethane.

Question 9

What are the two liquefied petroleum (LP) gases?

Answer 9

Propane and butane.

Question 10

What is added to fuel gases for safety?

Answer 10

Mercaptan is added as an odorant since natural gas, propane, and butane or non-toxic, tasteless, colorless, and invisible.

Question 11

What is another term for specific gravity?

Answer 11

Relative density.

Question 12

What is specific gravity?

Answer 12

The comparison between the weight of the volume of a vapor or liquid gas and the weight of an equal amount of air or water.

Question 13

Is natural gas heavier or lighter than air?

Answer 13

It is lighter than air with a specific gravity of 0.6.

Question 14

Is propane and butane heavier or lighter than air?

Answer 14

They are heavier than air. Propane has a sG of 1.52 and butane has a sG of 1.95.

Question 15

What are the expansion ratios of natural gas, propane, and butane?

Answer 15

Natural Gas: 600:1
Propane: 270:1
Butane 235:1.
These aren’t in the gas code so remember them.

Question 16

What are the maximum flame speeds of natural gas, propane, and butane?

Answer 16

Natural Gas: 25” Per second.
Propane: 32” Per second.
Butane: 33” Per second.
These aren’t in the gas code so remember them.

Question 17

What does it mean when a fuel mixture is too “lean”?

Answer 17

Not enough fuel in an air-gas mixture results in the mixture being too “lean.”

Question 18

What does it mean when a fuel mixture is too “rich”?

Answer 18

Too much fuel in an air-gas mixture results in the mixture being too “rich.”

Question 19

If 1 cubic foot of liquid natural gas at atmospheric pressure was vaporized, how much space would it occupy?

Answer 19

600 cubic feet.

Question 20

If 1 cubic foot of propane at atmospheric pressure was vaporized, how much space would it occupy?

Answer 20

270 cubic feet.

Question 21

If 1 cubic foot of butane at atmospheric pressure was vaporized, how much space would it occupy?

Answer 21

235 cubic feet.