ROUG11-AND-TUMBLB ENCINZXk 37 



obtain the most economical results the proper sized in- 

 jector must be used When the exact quantity of water 

 consumed per hour is known it can be easily determined, 

 from the cnj i^ivcn in the price lists, which sized 



injector must be selct 



An injector must always be selected having a m 

 mum c;t; : excess of the water consume 1. If the 



ount of water consumed per hour is not known, 

 and cannot be < ctermined, the proper size can 



be approximately determined from the nominal II. i 

 the tx)ilcr. The usual custom has been to allow 7J4 gal- 

 lons of water per hour per H. P. which is a safe rule for 

 the ordinary type of boiler. 



WHAT A GOOD INJECTOR OUGHT TO DO 



With cold feed a good injector with a two foot 



lift ought to th 25 pounds pressure and work up 



;o pounds. With an 8 foot lift, it ought to start at 

 30 pounds and work up to 130. With feed water heated 

 to loo degrees Fahrenl h a two 



foot lift at 26 pounds pressure and work up to 120 pounds 

 and at 8 feet from 33 up to IGO pounds. You will see by 



that conditions, consisting of variation of tempera- 

 ture in the feed water and different li npe the 

 efficiency of your injector very materially, and ti 



oon prt the cap:, our injector to work 



at all. The above refers more particularly to the single 



