CREAMERY BUTTER MAKING 197 



Gate Valve. As its name implies, this is a valve 

 closed by a gate. 



Throttle Valve. This is the valve that admits the 

 steam to the engine. 



Stop or Gas Valve. This is opened by giving it a 

 half turn. It is commonly used on receiving vats, and 

 on milk and skim-milk pipes. 



Rotary Valve. This is illustrated by the stop cocks 

 used on the boiler. 



Ball Valve. This is an automatic valve Illustrated by 

 the float that regulates the feed of the separator. 



Parts of a Globe Valve. These are : ( i ) chamber ; 

 (2) seat; (3) stem; (4) stuffing box; (5) disc; and (6) 

 handle. The chamber is the place where the valve oper- 

 ates. The disc is attached to the stem and closes the 

 valve by turning it onto the seat. 



Repairing of Globe Valves. There are three parts in a 

 valve that may cause it to leak : ( i ) the seat, (2) the disc, 

 and (3) the stem. In valves like the Huxley where the seat 

 and disc are replaceable, extras should always be kept 

 on hand so that either may be replaced when leaking. 

 In valves like the Jenkins where only the disc is replace- 

 able a "reseater" should be at hand whereby the seat of 

 the valve can be made to fit tight again. A reseater for 

 valves from one-half to one and one-half inches in 

 diameter can be bought for twenty-five dollars, and 

 creameries that use valves in which the seat is not re- 

 movable should be provided with one. 



The valve discs are made of various materials, but, for 

 ordinary steam pressure, brass and "composition" discs 

 are giving the best satisfaction. 



