What is the purpose of a fixed liquid level gauge on containers being filled by volume?

The purpose of a fixed liquid level gauge on containers being filled by volume is to indicate the maximum filling level. This device serves a crucial function by providing a visual or mechanical indication of how full the container is, which helps ensure that the container is not overfilled. Overfilling can lead to potential hazards, such as excessive pressure build-up due to thermal expansion of the liquid or liquid spilling out, which could result in environmental hazards or safety risks.

The fixed liquid level gauge is calibrated to specific levels, making it a reliable tool for operators to monitor how much liquid is in the container as it is being filled. By knowing the maximum filling level, operators can adhere to safe filling practices and comply with regulatory requirements related to the storage of liquefied gases.

Other options, while related to container management, do not accurately reflect the function of a fixed liquid level gauge. For example, monitoring pressure is managed by pressure gauges, temperature readings require thermometers, and preventing leakage during transfer involves proper sealing and connection techniques rather than a level gauge.