SANITARY PLUMBING 



507 



m 



level of the surface of water? Such a piece of apparatus is called a 

 SIPHON; the water is said to have been removed from the vessel by 

 SIPHONING. 



596. Explanation of the Siphon. In the experiment, the 

 water in the long arm of the siphon fell through the tube. In 

 so doing it tended td produce a vacuum in the upper portion, 

 the bend, oLthe tube. Air pressure upon the surface of the 

 water in the vessel forced the water up into the vacuum. 

 This water then fell and more 



water was forced up into the 

 bend. Thus the action con- 

 tinues till the level of the 

 water falls below the open end 

 of the tube in the vessel. How 

 does the air vent provided in 

 plumbing, then, prevent si- 

 phoning ? If a hole were made 

 in the rubber tubing used in 

 Ex. 98 at the top of the bend, 

 would it destroy its siphoning 

 action? 



597. The Siphon Flushing 

 Tank. The principle of the 

 siphon is utilized in the ordi- 

 nary flushing tank used in 

 connection with water closets. 

 Figure 3 14 shows the construc- 

 tion of such a flushing tank. The trap consists of a hollow 

 cast-iron cylinder about 3 in. in diameter and 12 in. in length. 

 A vertical partition extending nearly the entire length of the 

 trap divides its interior into two chambers, or rather into two 

 passages. One side of the trap, near its base, is so cut away 

 as to produce an opening into one of the two passages at that 

 point; the other passage opens downward directly into the 

 discharge pipe. The lower end of the trap fits tightly upon 

 a cushion so as to seal the passage into the discharge pipe 



B 



FIG. 314. The siphon flushing 

 tank. A. When not flowing; B. When 

 flowing. 



