WATER SUPPLY 



375 



of the seal in the traps of other fixtures. It is not necessary 

 to vent each fixture, as indicated in Figure 292, but this 

 is an additional precaution against the syphoning of the 

 traps, allowing for and equalizing the pressure on the two 

 sides of other traps when one fixture is being flushed. 



All horizontal runs should be given a little pitch to aid 

 in draining. It is a good practice to place no pipes in outside 

 walls on account of the 

 damage from frost. A kit- 

 chen sink may be placed 

 against an outside wall, 

 and the water pipes placed 

 inside the room, exposed. 

 A heating plant is necessary 

 before a water system is 

 installed, in order that the 

 house and cellar tempera- 

 ture may not go below the 

 freezing point. 



Fixtures. Fixtures 

 should have a hard, 

 smooth, impervious sur- 

 face . The best the market 

 affords are made of enam- 

 eled iron, or porcelain on 

 iron, and of clay. The last 

 is too expensive except in 

 the closet. Of the other 

 two, the porcelain on iron 

 is much more common and 

 is known as the standard. 



For the kitchen a rolled- Fig 

 rim sink, with back, is 

 good; but an objection is raised because of the difficulty 

 found in placing work table and drain board up to it. A 

 flat-rim sink is better in this respect, but has no back. 



/ 6 'Sexw prpf 



After University of Minnesota 



292. Soil pipe, vent pipes, and trap 

 for house installation 



