What is a fixed liquid level gauge primarily used for?

A fixed liquid level gauge is primarily utilized to indicate how full a tank is, making it especially valuable during the filling process. Its design allows it to provide a consistent reference point for the liquid level, typically set at around 80% capacity for safety and compliance with regulations. This is crucial because it helps prevent overfilling, which can lead to dangerous situations such as leaks or spills.

While it may also provide some level of ongoing measurement, the primary function isn't necessarily to measure the liquid level continuously. Instead, it focuses on providing a clear, robust indication of when the tank reaches that critical 80% threshold, often associated with safety protocols regarding fill limits.

Other options, such as controlling pressure or gauging temperature, address different aspects of tank management and don’t reflect the main purpose of a fixed liquid level gauge. Understanding the primary use of such gauges aids in enhancing safety while handling and storing liquefied petroleum gases.