and 



BOILERS AND GENERATION OF STEAM 313 



A X P X I - (VI X g) 



L = 



W 



EXAMPLE. At what distance from the center of fulcrum must a 

 weight be placed, if the boiler pressure is 100 Ibs., weight is 16 Ibs., 

 area of valve is 3 sq. in., and valve and lever weigh 16 Ibs., center 

 of valve is 2^ in. from fulcrum, and center of gravity is 12 in. from 

 fulcrum? 



3 X 100 X 2^ - (16 X 12) 



n. 



16 



354. Water Gauge. The function of the water gauge 

 (Fig. 166) is to register the height 

 of the water in the boiler. It 

 consists of a small cast iron drum 

 placed in an upright position in 

 front of the boiler, provided with 

 a glass gauge, cocks, water and steam 

 connections. Pipe connections are 

 arranged so that steam enters the top 

 and water enters the bottom. Water 

 gauge and cocks are essential to the 

 safety of the boiler and should be 

 blown out frequently to prevent clog- 

 ging. Water should stand half- 

 way in a gauge glass cock while 

 working, and at night should be 

 raised to the top gauge cock. 

 The first duty of a fireman in 

 taking charge of his boiler is to 

 see if the water is at a proper FlG " l^.-Water Gauge, 

 level. To tell if the glass is registering correctly, the gauge 

 cocks must be tried. The water column should be blown 



