Gas - Properties of Gas, Conversions and Pipe Sizing

Question 1

What is the expansion ratio of Butane?

Answer 1

235 ft³ : 1

Question 2

What is the expansion ratio of Propane?

Answer 2

270 ft³ : 1

Question 3

What is the expansion ratio of Natural Gas?

Answer 3

600 ft³ : 1

Question 4

What is the flame speed of Natural Gas?

Answer 4

25” / Second

Question 5

What is the flame speed of Propane?

Answer 5

32” / Second

Question 6

What is the flame speed of Butane?

Answer 6

33” / Second

Question 7

What is the name of the odourant that they put into Natural Gas to give it the distinct smell?

Answer 7

Mercaptan.

Question 8

Propane and Butane are often referred to as what types of gases?

Answer 8

LP Gases.

Liquefied petroleum.

Question 9

What is considered low pressure in the world of gasfitting?

Answer 9

1/2 psig or less.

14” water column or less.

Question 10

What is considered low volume in the world of gas fitting?

Answer 10

400 Mbh or less.

400,000 Btuh or less.

Question 11

What is the manifold pressure in gas systems?

Answer 11

Natural Gas: 3.5” w.c.

Butane and propane: 11” w.c.

Question 12

1 kW equals how many Btu’s?

Answer 12

3412.

Question 13

1 m³ equals how many ft³?

Answer 13

35.31

Question 14

1 psi equals how many inches water column?

Answer 14

27.72

Question 15

1 psi equals how many feet of head?

Answer 15

2.31

Question 16

1 psi equals how many kilopascals?

Answer 16

6.895

Question 17

1 psi equals how many ounces per square inch (OSI)?

Answer 17

16.

Question 18

1 psi equals how many inches of mercury?

Answer 18

2.04

Question 19

The amount of energy (heat) in a given volumn is the definition of?

Answer 19

Calorific value.

Question 20

What is the calorific value of air?

Answer 20

0.

Question 21

State the calorific value of Natural Gas in the four different ways that we may need to refer to it?

Answer 21

1000 btu / ft³

0.293 kW / ft³

35,310 btu / m³

10.35 kW / m³[][]

Question 22

What is standard pressure?

State your answers in both psi and kPa.

Answer 22

14. 7 psi.
15. 325 kPa.

Question 23

What is standard temperature?

State your answer in both Celcius and Fahrenheit.

Answer 23

15°C.

60°F.

Question 24

When calculating the LMR (longest measured run) where does the calculation start and where does it end?

Answer 24

It starts at the gas meter or regulator and ends at the furthest appliance.

Question 25

When are you required to add fittings into your calculation?

Answer 25

On a system that’s 2 psig or greater.

Question 26

Which of the following gases is considered to be inert?

A. H20.

B. N2[]]

C. O2[]]

D. CH4.

Answer 26

B. N2.