THE HOME SYSTEM OF DRAIN PIPES 



Experiment. To understand how the flush tank works. 



Remove the cover from the flush tank. (A) Pull the lever to allow the 

 water to run out. Locate the inlet valve. Where is it? What con- 

 trols it ? Make a diagram to show clearly how the water inlet is con- 

 trolled. (B) Hold the ball-float valve to prevent more water entering 

 the tank. Pull the lever to empty the tank. Notice whether the tank 

 is emptied by use of a siphon or whether there is a rubber ball valve. 

 If it has a ball valve, fill with water again and empty. Observe just 

 when the ball closes the valve. Can you explain why the valve stays 

 open just so long? Make one or more diagrams to show the empty- 

 ing mechanism. How would you make repairs if the rubber valve 

 leaked? What would you do if the ball float were broken off? 



The home system of drain pipes. In order to get water 

 and wastes out of the house it is necessary to have a system 

 of drain pipes consisting 

 of a large soil pipe from 

 cellar to roof. All the 

 sinks, toilets, and tubs 

 must connect with this 

 soil pipe. It is neces- 

 sary, then, to arrange our 

 house so as to have all 

 of the fixtures grouped 

 about this drain pipe. 

 The pipe must leave the 

 house at a point slightly 

 lower than at any other 

 place, and all pipes leav- 

 ing fixtures must also 

 run slightly down hill. 

 The large and straight 



pipes are usually iron with the joints tightly closed 

 by means of cement substances, while the smaller pipes 

 are usually lead. In order to prevent odors from de- 



An S-trap showing water seal and vent. 



