Gas Fitter Practice Test

What is the maximum permitted filling density of a cylinder with liquid propane by liquid volume?

1. 42%

2. 60%

3. 80%

4. 90%

The correct answer is: 80%

The maximum permitted filling density of a cylinder with liquid propane is set at 80% of the cylinder's liquid volume. This limit is crucial for safety reasons, as it allows for the expansion of propane due to temperature fluctuations and prevents excessive pressure buildup within the cylinder. When propane is filled to a density higher than the permitted level, it can lead to dangerous situations such as overpressure, leaks, or even explosions due to the inability of the cylinder to safely contain the liquid as it expands. By adhering to this 80% filling density standard, operators and users ensure that there is an adequate vapor space above the liquid propane. This vapor space is essential for the effective operation of gas appliances, as it allows for the vaporization of propane so that it can be safely used as a fuel. In contrast, other options suggest filling densities that are either too low or too high. A lower density may not be practical for storage efficiency, while any density above 80% compromises safety regulations associated with the safe transport and storage of liquefied petroleum gases. Thus, understanding and implementing the 80% filling density guideline is vital for safe handling practices in the use of cylinders filled with liquid propane.