TRANSFORMERS 



435 



(Fig. 273) the water may be admitted to, shut-off from, or drained 

 from the coil, the draining being by gravity. 



Water-flow indicators are desirable in order to enable the 

 attendants to quickly observe that the water is flowing inasmuch 



FIG. 273. Typical Transformer Installation Showing Water Piping Con- 

 nections and Three-way Valve. 



as most water-cooled transformers would overheat in a short time 

 if the water supply were shut off. There are two kinds of flow 

 indicators in general use. The sight-flow indicator and the check- 

 valve indicator. The former is of the open type and consists of a 



