Table 1-2.—Boiler Accessories, Its Location, and Function

Table 1-2.—Boiler Accessories, Its Location, and Function—Continued ITEM ACCESSORY LOCATION PURPOSE 10 11 12 13 14 15 16 17 18 19 Temperature regu- lating valve (TRV) Heat exchanger Strainer Condensate line Condensate/makeup tank Feed pump Feedwater pipe Relief valve Feed check valve Feed stop valve Install in the steam supply line close to equipment needing temperature regulation (sensing element is installed at a point where the temperature is to be controlled, such as the hot- water discharge side of a heat exchanger Locate as close as practical to the source for which it is going to supply heated water or oil Install in steam and water lines just ahead of PRVs, TRVs, steam traps, and pumps Return line extends from the discharge s i d e o f s t e a m t r a p s t o t h e condensate/makeup feedwater tank Close to the boiler as practical and at a higher level than the boiler feed-pump suction line Supplies water to the boiler as required This line extends from the discharge side of the feedwater pump to the boiler shell or drum (installed below the steaming water level) Between the feed pump and the nearest shutoff valve in the external feed line Between the feed pump and the stop valve in the feed-water pipe In the feedwater line as close to the boiler as possible between the boiler and feed check valve Control steam flow through a vessel or heating equipment An unfired pressure vessel that contains a tube nest or electrical element. Used to heat oil or water Prevent malfunctions or costly repairs to equipment and com- ponents by trapping foreign matter, such as rust, scale, and dirt Carry condensed steam back through piping for reuse in the boiler or heating vessel Provide storage space for condensate and makeup/feedwater and vent noncondensable gases to the atmosphere Installed between the condensate/ makeup/feedwater tank and the boiler sheall or steam drum Provide feedwater to the boiler when required Relieve excessive pressure should the external feed line be secured and the feed pump started accidently. A ruptured line or serious damage to the feed pump could occur if there were no relief valve Prevent backflow from the boiler through the feedwater line into the condensate/feedwater tank during the off cycle of the pump Permit or prevent the flow of water to the boiler 1-16