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 below can approximate this information at room temperature. In addition, there are helpful calculator applications available here.
Rupture Formula for Tubing
S = pr/t
S = Hoop Stress in Pa
P = Working Pressure (Pa)
r0 = Inside Radius (mm)
t = Wall Thickness (mm)
This formula cannot 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 temperature 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. Actual pressure points may vary depending on user applications.