110 



Our Surroundings 



In using this system, it must be kept in mind that the pipes 

 will burst in cold weather from the freezing of any water left 

 in them after the fire in the boiler has gone out. Therefore it 

 is wise to drain the pipes whenever the plant is not in use. For 



Expansion 

 Tank 



International Heater Co. 



A HOT WATER HEATING SYSTEM 



Trace the course of the water in each circuit. 



this reason, also, the valves of the radiators should never be closed 

 in very cold weather since this would prevent the entrance of hot 

 water into the radiators. 



