Question 151Steam Plants - QMED

The correct answer is A) Purge the furnace of combustible gases. Purging the furnace of combustible gases before lighting off a boiler is a critical safety precaution. This removes any unburnt fuel or gases that could otherwise ignite explosively when the burner is lit. The other options are not the primary safety step required before lighting off a boiler. Blowing down the mud drum, closing the air register, and securing steam line drains are important operating procedures, but do not directly address the risk of an explosive ignition, which is the primary hazard that must be mitigated before lighting off the boiler.