PRINCIPLES OF NAVAL ENGINEERING 



taken to prevent damage. For example, a 

 casualty to the main engines might call for a 

 sudden large reduction or even a complete 

 stoppage of steam flow. Even if the superheater 

 burners are secured, there will still be a need 

 for steam flow to protect the superheater from 

 the heater of the furnace. In this event, or when- 

 ever a greater flow is required than can be 

 obtained by ordinary means, lift the superheater 

 safety valves by hand to ensure a positive flow 

 of steam through the superheater . 



When the superheater thermal alarm sounds, 

 the superheater fires must be immediately de- 

 creased to bring the temperature below alarm 

 temperature. Do not decrease the temperature 

 further than necessary. It is very seldom 

 necessary to secure all superheater burners 

 in order to bring the temperature down to the 

 prescribed point. 



CASUALTIES TO REFRACTORIES 



If brick or plastic falls out of the furnace 

 walls and goes unnoticed, burned casings may 

 result. If brick or plastic falls out of a furnace 

 wall, if practicable, secure all the burners. 

 If it is not practicable to secure all the burners, 

 secure those burners which are adjacent to the 

 damaged section. NOTE: It may be necessary 

 to continue operating the boiler until another 

 boiler can be brought in on the line, 



CASUALTIES TO BOILER 

 PRESSURE PARTS 



When boiler pressure parts, such as tubes, 

 carry away or rupture, escaping steam may 

 cause serious injury to personnel and damage 

 to the boiler. It is urgent that the boiler be se- 

 cured, relieved of its pressure, and cooled until 

 no more steam is generated. If a boiler pres- 

 sure part carries away or ruptures, take steps 

 immediately upon discovery of the casualty, to 

 minimize and localize the damage as much as 

 circumstances will allow. 



Gage glasses are connected to the water and 

 steam spaces of the steam drum. If a water 

 gage glass carries away, the mixture of steam 

 and water escaping from the gage connections 

 may seriously burn personnel in the area. A 

 ball check valve in the high pressure gage line 

 functions when the flow is excessive. In addi- 

 tion, the hazard of flying particles of glass 



makes this casualty very serious. The particles 

 of glass could lodge in your eyes and blind you, 

 or they could lodge elsewhere in your body and 

 cause serious injury. If a gage glass casualty 

 occurs, throw a large sheet of asbestos cloth, 

 rubber matting, or similar material over the 

 glass. Then take immediate action to secure 

 the gage glass. 



PRECAUTIONS TO PREVENT FIRES 



The following precautions must be taken to 

 prevent fires: 



1. Do not allow oil to accumulate in any 

 place. Particular care must be taken to guard 

 against oil accumulation in drip pans under 

 pumps, in bilges, in the furnaces, on the floor 

 plates, and in the bottom of air-encased boilers. 

 Should leakage from the oil system to the fire- 

 room occur at anytime, immediate action should 

 be taken to shut off the oil supply by means of 

 quick-closing valves and to stop the oil pump. 



2. Absolutely tight joints in all oil lines 

 are essential to safety. Immediate steps must 

 be taken to stop leaks whenever they are dis- 

 covered. Flange safety shields should be in- 

 stalled on all flanges in fuel oil service lines 

 to prevent spraying oil on adjacent hot surfaces. 



3. No lights should be permitted in the fire- 

 room except electric lights (fitted with steam- 

 tight globes, or lenses, and wire guards), and 

 permanently fitted smoke indicator and water 

 gage lights. If work is being done in the vicinity 

 of flammable vapors, or if rust-preventive com- 

 pound or metal-conditioning compound is being 

 used, all portable lights should be of the ex- 

 plosion proof type. 



BOILER MAINTENANCE 



The engineer officer must keep himself fully 

 acquainted with the general condition of each 

 boiler and the manner in which each is being 

 operated and maintained. He must satisfy him- 

 self, by periodic inspections, that the exterior 

 and interior surfaces of the boiler are clean; 

 that the refractory linings adequately protect 

 the casing, drums, and headers; that the integ- 

 rity of the pressure parts are being maintained; 

 and that the operating condition of the burners, 

 safety valves, operating instruments, and other 

 boiler appurtenances are satisfactory. 



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