G2 Gas Fitter Practice Exam

What is the specific gravity of natural gas?

1. 0.5

2. 0.6

3. 0.9

4. 1.0

The correct answer is: 0.6

Natural gas typically has a specific gravity that averages around 0.6 when compared to air. This means that natural gas is lighter than air, which is an important safety consideration in its use and handling. A specific gravity of 0.6 indicates that natural gas will rise in the atmosphere, as gases with a specific gravity less than 1 will be buoyant in air. When evaluating other options, it's clear that a specific gravity of 0.5 is lower and may be encountered in certain natural gas blends, but it is not the most representative average. A specific gravity of 0.9 suggests that the gas is relatively heavy compared to air and would not accurately reflect the properties of standard natural gas. Finally, a specific gravity of 1.0 indicates that the gas would have the same density as air, which is not characteristic of natural gas. Understanding specific gravity is essential for gas fitters, as it impacts safety, venting, and overall system design.