Tubular Gage Glasses    
 Corrosive chemicals    
The borosilicate glass used to manufacture these products is 
outstanding for chemical services. Certain limitations, however,
must be recognized.        
A few of these limitations are do to contact with certain materials.
Some materials reduce the useful life of the gage glass by
chemical action: e.g. hydrofluoric acid (HF), hot concentrated
phosphoric acid; sodium and potassium hydroxides above
125 degrees F; steam and superheaded wate above 250
(see the graph below).      
Alkaline solutions attack glass very slowly at room temperatures,
but as the temperature is increased over 100 degrees F, the
corrosion rate rise rapidly.      
The accompanying graph illustrates how the rate of attack 
increases with temperature and concentration  


Sources: Corning Incorporated brochure "Tubular Gage Glasses"
Copyright 1991.