Properties of Fused Quartz Silica is found almost everywhere in nature, it represents almost 1/3 the mass of the earth’s crust. Vitreous Silica is the generic term used to describe all types of silica glass, with manufacturers referring to the material as either Fused Quartz or Fused Silica. Manufactured by fusing naturally occuring crystalline silica, either sand or rock crystal, a wide range of products are available. After this process, their appearance wil be wither opaque, translucent or transparent. If the silicon dioxide is synthetically derived, the material produced is commonly called Synthetic Fused Silica. Vitreous Silica, in all its forms, offers a variety of properties such as:
 
 
 
INTERNAL PRESSURE CALCULATIONS  
RUPTURE FORMULA FOR TUBING  
Because fused quartz is used in applications involving internal pressures, it is helpful to know the maximum pressure that can be applied to a selected fused quartz tube. The formula at right can approximate this information at room temperature.  
S = pr/t  
Where:  S = Hoop Stress in Pa  
p = Working Pressure (Pa)  
r_{0} = Inside Radius (mm)  
t = Wall Thickness (mm)  
This formula can not be used when internal pressure exceeds 100 psi.  
RUPTURE PRESSURE CALCULATIONS FOR DISCS AND PLATES  
Determining pressure differential is required for many applications of stressed fused quartz discs, plates and sight glasses. The formulas below can be used for room temperture applications of parts having either clamped or unclamped edges.  
A = Unsupported Area in sq/inches T = Thickness (inches) F = Safety Factor (7) M = Modulus of Rupture (7,000 psi) P = Pressure (psi)  
THE ABOVE PRESSURE CALCULATIONS ARE RECOMMENDATIONS ONLY.  
