ROCGU-AND TUM1LC t.N 



PUMPS 



or\ boiler should have two boiler feeders, either 

 pumps or two injectors, or an injector and a pump. Both 

 of them should be in good working order all the time, as 

 the safety of the boiler Jepends entirely upon them. It 

 does not matter very much what particular boiler feeder 

 is used so long as it is in good working order. There 

 are dependent pumps and independent pumps, single tube 

 and double tube injectors. They all may be made to work 



ictorily and with about equal certa 



e question is often asked, "Which is more satisfac- 

 tory, a cross head pump or one of the independent 

 pumps ?" This is a question that is not easily answered off 

 It depends a good deal upon circumstances and 

 upon the engineer's knowledge of machinery. The cross 

 head pump is a little easier to manage as a rule, than the 

 independent pump, but it has a disadvantage of never run- 

 ning except when the engine runs. It is the simplest 

 pump made and rarely jrivcs any trouble. All that is 

 necessary to do in order to stop it is to shut off the water 



