American Society of Mechanical Engineers (ASME) Practice Exam 2025 - Free ASME Practice Questions and Study Guide

When the water level in the gauge glass does not recede into the visible range after a two-minute interval, it indicates a potential issue with the water level in the boiler system. The appropriate action is to open the main blowoff valves. This action is crucial as it allows for the removal of any sediment or sludge that may have accumulated, which could obstruct the flow of water within the system. By doing so, it can help restore proper visibility of the water level and ensure that the boiler operates within safe parameters.

Opening the blowoff valves also helps in assessing the actual water condition in the boiler, as it provides an opportunity for any trapped gases or steam pockets to escape, allowing for a more accurate reading of the water level. This step is essential for maintaining the safety and efficiency of boiler operations.

Calling emergency services may be considered in severe situations, but it is generally not the first action in this specific instance. Adjusting the fuel flow or restarting the boiler does not directly address the issue of insufficient water visibility in the gauge glass, which is fundamental for safe operation. Therefore, opening the main blowoff valves is the most suitable action in this scenario to enable proper monitoring and troubleshooting of the water level issue.