CREAMERY MECHANICS 



305 



The stuffing box of the valve is packed with asbestos 

 to which a mixture of oil and graphite is first added. This 

 packing will prevent the stem from leaking. The burr 

 of the stuffing box must be tightened from time to time 

 when it shows signs of leaking. 



In case of water valves the stuffing boxes are best 

 packed with oiled candle wicking. 



UNING UP SHAFTING. 



A 



6 



D 



Fig. 92. Intersecting planes. 



Pig. 93. An aid to lining 

 up shafts. 



Fasten a heavily chalked string along the ceiling paral- 

 lel to the direction the shafting is to take. Snap the 

 string, and a white mark will indicate the position of the 



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