You find the boiler water-level gauge glass to be empty and the burner firing. What is your course of action? (Assuming the gauge glass to be clear & good working order)
A. Blow down the gauge glass to determine where the water level is
B. Increase the feedwater supply to maintain the water level
C. Start the emergency feedwater injector to restore normal water level
D. Shut down the boiler to minimize damage to the boiler tubes
And the answer is…
Answer: D. Shut down the boiler
Normally a boiler is provided with two independent sensors for emergency low water level burner cut-outs. So this would never happen. However, if it does, don’t take any chances! Shut off the burners immediately!
Before you start raising the level in the boiler you have to find out if any part of the furnace walls has been overheated. If you raise the level over a glowing steel-wall then the boiler might produce more steam than the safety valves can handle and a nasty explosion would be the result.