Low Boiler Level

[mattski72]

I have a 400 HP scotch marine, two pass, fire tube boiler. I am writing the casualty procedure for a low out of site boiler level (below the upper most tubes and the site glass) . If the boiler is not operating (burner not running) should it be treated as the same as when the boiler was operating (burner running)? Is there a temperature/pressure threshold or other criteria for the boiler at which it becomes a non-casualty?

 

[rmw]

When you say the boiler is not opearating, do you mean as in stone cold, not started up? Or do you mean during burner cycles when the burner has cycled off?

If the former, it is not too critical, but you don't want to start it until you have normal water level or at least water somewhere you can see it in the glass.

If the latter, same recommendation as above, but it is critical because there is residual heat in the furnace and flue gas path that include the top row of tubea (or more) that are without water.

rmw

rmw

 

[mattski72]

RMW

Thanks, yes you expressed the same concern I had about residual heat. In regard to "operating" I meant at normal temp and pressure, burner on (operating) or off(not operating).

I am trying to determine when a low out of site level is a casualty and when it is not. Obviously, burner on at any temp or press and a low level is a casualty. But what if it is at normal temp and press and the burner has been off for 30 min or an hour. If level is low then, is it a casualty in the same degree as if the burner were running? At what point does the residual heat become a non-concern?