STEAM INSTALLATION 191 



do large pipes. Large cast-iron pipes are 

 almost never used in steam heating. 



When i-inch pipe is employed coils may be 

 safely used up to 75 feet in length; i*A- 

 inch up to 150 feet; and i^-inch up to 250 

 feet. As with hot water, better results and a 

 more uniform temperature may be secured 

 by using two or more comparatively short 

 coils, rather than one which is excessively 

 long. In small houses it is possible to run 

 the coils entirely around the house, maintain- 

 ing an even downward slope. 



Arrangement of Coils. As indicated in a 

 preceding paragraph, either of two methods 

 of piping may be used. In one the water 

 resulting from the condensation of the steam 



Fig. 99. A corner coil. It allows for expansion of the 

 pipes 



