Chapter U-BOILER FITTINGS AND CONTROLS 



CHEVRON DRYERS 



DRY BOX 



HORIZONTAL STEAM 



SEPARATOR 

 \ 



STEAM 

 BAFFLES 



BAFFLES 



^DESUPERHEATER 

 CHEMICAL FEED DESUPERHEATER INLET 



38.48 

 Figure 11-8.— Arrangement of internal fittings 

 in newer single-furnace boiler (DE 1006 class 

 ship). 



Figures 11-10, 11-11, 11-12, and 11-13 show 

 the locations of many external fittings and con- 

 nections on a recent 1200-psi single-furnace 

 boiler. As you study the following information on 

 external fittings and connections, you may find it 

 helpful to refer to these figures to see where the 

 various units are installed on or connected to 

 the boiler. Remember, however, that the illus- 

 trations shown here are for one particular 

 boiler and that differences in boiler design lead 

 to differences— in the type and location of ex- 

 ternal fittings and connections. Drawings show- 

 ing the location of external fittings and connec- 

 tions are usually included in the manufacturer's 

 technical manuals for the boilers on each ship. 



The maintenance of external fittings is of 

 vital importance to the proper operation of the 

 boiler. Therefore, all maintenance shall be 

 conducted in accordance with the Planned 

 Maintenance Subsystem of the 3-M System. 



Drains and Vents 



The main part of the boiler, the economizer, 

 and the superheater— in short, all the steam and 

 water sections of the boiler— must be provided 

 with drains and vents. 



OUTLET 

 ORIFICE 



38.49 

 Figure 11-9.— Horizontal steam separator. 



The main part of the boiler may be drained 

 through the bottom blow valves (described later 

 in this chapter) and through water wall header 

 drain valves. It is vented through the aircock, 

 which is a high pressure globe valvel installed 

 at the highest point of the steam drum. The 

 aircock allows air to escape when the boiler is 

 being filled and when steam is first forming; it 

 also allows air to enter the steam drum when 

 the boiler is being emptied. 



The economizer is vented through a vent 

 valve on the economizer inlet piping. It is 

 drained through a drain line from the econono- 

 mizer outlet header. Another drain line, this 

 one coming from the drain pan installed below 



Basic types of valves are discussed in chapter 14 of 

 this text. 



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