Glass tubes usually use high borosilicate glass.
The linear expansion coefficient of G3.3 high borosilicate glass is 3.3 0.1×10-6/K, which is a kind of glass with sodium oxide (Na2O), boron oxide (B2O3) and silicon dioxide (SiO2) as the basic components. The content of borosilicate in the glass composition is high, respectively, boron: 12.5~13.5%, silicon: 78~80%, so it is called high borosilicate glass. PYREX glass belongs to borosilicate glass. Acid, alkali and water resistance, excellent corrosion resistance, with good thermal stability, chemical stability and electrical properties, so it has chemical erosion resistance, thermal shock resistance, good mechanical properties, high temperature resistance characteristics.
Compared with common glass, harmless side effects, its mechanical properties, thermal stability, water resistance, alkali resistance, acid resistance and other properties are greatly improved, can be widely used in chemical, aerospace, military, family, hospital and other fields, can be made into lamps, markers, telescope, washing machine observation hole, microwave plate, solar water heater and other products, with good promotion value and social benefits.