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

The maximum permitted filling density of a cylinder with liquid propane is established to ensure safety during the transportation and storage of the gas. Liquid propane expands as it warms, and if a cylinder is filled beyond the recommended density, there could be an increased risk of pressure build-up as temperatures rise, leading to potential failures in the cylinder and hazardous situations.

Filling the cylinder to a density of 80% allows for this thermal expansion while maintaining the integrity of the container. This percentage provides adequate space for the liquid propane to expand into vapor when temperatures increase, preventing excessive pressure that could result in leaks or a catastrophic failure of the cylinder.

In contrast, filling densities lower than 80% do not maximize the utilization of the cylinder's capacity, while densities higher than 80% significantly increase the risk of safety hazards associated with the expansion of the liquid. Hence, 80% is the established and accepted standard for filling density in propane storage and transport.