Question 267Steam Plants - 1st Asst/Chief

The correct answer is A) close the main steam stop. When a boiler's water level drops out of sight low in the sight glass and the burners have been secured, the proper action is to immediately close the main steam stop to isolate the affected boiler from the main steam system. This helps prevent damage to the boiler and associated piping by preventing the low water condition from causing a steam explosion. The other options are incorrect because: B) manually feeding the boiler would not address the immediate safety concern, C) blowing down the gage glass does not resolve the low water condition, and D) starting the standby feed pump would not isolate the affected boiler from the system.