NVIC 17-14 Task 4.3.L

Operate main and auxiliary machinery and associated control systems

OICEW-A4.3 Preparation, operation, fault detection and necessary measures to prevent damage for the following machinery items and control systems

Steam boiler and associated auxiliaries and steam systems

On a vessel of at least 1,000 HP, on a simulator, or in a laboratory, under the supervision of the Chief Engineer, and when directed,

the candidate performs a bottom blow of a boiler.

The candidate:

1. Performs bottom blow when directed, slowing main engine to prevent carry-over or other adverse affects on steaming boiler;

2. Secures fires in boiler and opens superheater vent to boiler;

3. Secures main-steam stops to boiler to be given bottom blow;

4. Using auxiliary feed stop-check, raises level of water in steam drum of boiler to 1 inch from the top of gauge glass;

5. Opens bottom blow overboard skin valve;

6. Opens water wall bottom blow valve;

7. Observes drop in water level, securing bottom blow valve when level is no less than 1 inch from bottom of gauge glass;

8. Repeats steps 4 and 5;

9. Opens mud drum bottom blow valve and secures when gauge glass water level drops to no less than 1 inch from the bottom;

10. Prepares to re-light boiler;

11. Starts boiler forced draft fan and pre-purges furnace for 5 minutes;

12. Raises water level to 2 inches below normal level;

13. Re-lights burner and adjusts combustion air as necessary;

14. Opens main steam stops to “float” boiler back on line, cracks open superheater and main steam line drains;

15. Begins to return main engine to sea speed when boiler pressures are observed to be equal and slight drop in burner manifold fuel oil pressure is noted;

16. Closes off superheater and main steam drains, and superheater vent;

17. Continues to slowly re-establish engine speed; and

18. Conducts round of engine room to verify that all steam systems and equipment are operating at normal levels.