The fixed maximum liquid level gauge is ______ when filling a forklift cylinder by volume.

The fixed maximum liquid level gauge is opened when filling a forklift cylinder by volume to ensure safe and proper filling. This gauge serves as a visual indicator to show the maximum liquid level the cylinder can safely accommodate. By being opened during the filling process, it allows for the monitoring of the liquid's ascent within the cylinder, preventing overfilling and ensuring the safe operation of the forklift.

When the gauge is opened, it allows gas to escape if the liquid level reaches the maximum, thus preventing pressure build-up and reducing the risk of a hazardous situation. Proper use of the fixed maximum liquid level gauge is crucial in maintaining safety standards during LP-gas dispensing, ultimately protecting both the equipment and personnel involved in the operation.