Why should propane lines be bled after use?

The correct answer is based on the fact that propane, when heated or when there is a reduction in pressure, can expand. If there is still propane in the lines, this expansion can create high pressure, which may lead to the risk of rupturing the lines. Bypassing this step of bleeding the lines poses a significant safety hazard, as the pressure buildup could result in the lines breaking, causing leaks and potential fire hazards.

Bleeding the propane lines helps mitigate this risk by ensuring that any residual gas is released and that there is no buildup of pressure that could compromise the integrity of the lines. Proper maintenance of propane lines, including bleeding them after use, is essential to ensure safety and prevent accidents in environments where these fuel sources are utilized.

Other options, while relevant to safety and operational integrity in various contexts, do not directly address the primary concern about the consequences of propane expansion and the potential danger it poses to the lines.