Emergency Procedures, Accident Prevention and Abnormal Conditions
Low water
The most dangerous condition. Secure the burner immediately. If the level is not visible in the glass after the prescribed check, do not feed water into a hot boiler whose heating surfaces may be uncovered - adding water can cause a violent collapse or explosion. Shut down, allow controlled cooling, and require an inspection before returning to service. Feeding first and asking later is the classic wrong answer.
High water, carryover and flame failure
On high water, stop the feed, blow down carefully, and watch for carryover that can damage traps and turbines. On flame failure, the programmer locks out; purge fully before any relight attempt.
Fuel, power and mechanical failures
For a gas or oil leak, shut off the fuel at the source, ventilate, eliminate ignition sources, evacuate and call for help. On a power failure the burner stops; watch pressure and level, keep feed capability, and expect the safety valve to lift if firing is restored improperly. A tube rupture or furnace explosion calls for immediate fuel shutdown, isolation, controlled cooling and notification of the state authority, the insurer and the inspector. Preserve the scene.
Accident prevention
Lockout/tagout before work, confined space entry procedures for drum interiors, and correct personal protective equipment prevent most serious injuries.
Rule of thumb
In any emergency, secure the fuel first, then combustion air, then protect water level, then notify.