Propane

Butane

Formula

C₃H₈

C₄H₁₀

Boiling point F.

-44°

32°

Specific gravity - gas (air = 1.00)

1.53

2.00

Specific gravity - liquid (water = 1.00)

0.51

0.58

Lbs./gallon - liquid @ 60°F.

4.24

4.81

BTU/gallon - gas @ 60°F.

91690

102032

BTU/lb. - gas

21591

21221

BTU/ft.³ - gas @ 60°F.

2516

3280

Ft.³ of vapor @ 60°F./gal. of liquid @ 60°F.

36.39

31.26

Ft.³ of vapor @ 60°F./lb. of liquid @ 60°F.

8.547

6.506

Latent heat of vaporization @ boiling point BTU/gal.

785.0

808.0

Combustion data:

Ft.³ air required to burn 1 ft.³ gas

23.86

31.02

Flash point, F.

-156

N.A.

Ignition temperature in air, F.

920-1020

900-1000

Maximum flame temperature in air, F.

3595

3615

Limits of inflammability % of gas in air mixture:
    At lower limit - %
    At upper limit - %

2.4
9.6

1.9
8.6

Octane number (ISO-octane=100)

100+

92

Multiply Flow of

By

To Obtain Flow Of

Air

.707
1.290
.808

Butane
Natural Gas
Propane

Butane

1.414
1.826
1.140

Air
Natural Gas
Propane

Natural Gas

.775
.547
.625

Air
Butane
Propane

Propane

1.237
.874
1.598

Air
Butane
Natural Gas

Multiply

By

To Obtain

Pressure

Atmospheres

14.70

pounds per square inch

Atmospheres

407.14

inches water

Inches of mercury

1.133

feet of water

Inches of mercury

.4912

pounds per square inch

Inches of water

.0735

inches of mercury

Inches of water    

5.204

pounds per square foot

Inches of water

.0361

pounds per square inch

Inches of water

.5781

ounces per square inch

Pounds per square inch

06804

atmospheres

Pounds per square inch

2.036

inches of mercury

Pounds per square inch

2.307

feet of water

Pounds per square inch

27.67

inches of water

Metric

Atmospheres

1.0332

kilograms per sq. centimeter

Grams per sq. centimeter

.0142

pounds per square inch

Kilograms per sq. centimeter

14.22

pounds per square inch

Kilograms per square meter

.2048

pounds per square foot

Pounds per square inch