What is the primary purpose of overfilling prevention devices for propane containers?

The primary purpose of overfilling prevention devices for propane containers is to protect against overfilling. These devices are designed to prevent the liquid propane from being filled beyond a safe level within the container, which can lead to dangerous situations such as leaks or pressure buildup. By ensuring that propane containers are not overfilled, these devices help maintain the integrity of the container and minimize the risk of accidents related to excessive pressures and potential releases of propane gas.

This is critical for safety, as overfilled propane containers can expand when heated, leading to increased pressure that might exceed the container's design limits. By preventing overfilling, these devices are integral in ensuring that propane containers operate safely under various temperature conditions. Thus, their main function directly relates to safety by controlling the maximum amount of liquid propane in the container, rather than just focusing on the other aspects such as installation or leak prevention.