Table 4. Catastrophic Failure of EDU Acrylic Plastic 
Windows Under Sustained Long-Term Hydrostatic Loading 
Window Diameter | Thickness Sustained Pressure } Duration of Loading 
inches (D,) inches (t) psi minutes 
NOTE: 1. All windows were pressurized at 650 psi/minute 
rate till specified pressure was reached, this 
pressure was subsequently maintained till failure 
took place. 
2. Ambient temperature for all tests was 120°F. 
3. 0.025-inch thick neoprene impregnated cloth was 
used as the bearing gasket on the flange seat 
under the window. 
4. No retaining ring was used to restrain the window 
in the flange. 
5. *Test was terminated; no cracks were observed in 
the window. 
6. The windows were fabricated from Swedlow 350 
acrylic plastic. 
7. The opening in the flange (D,) was 3.000 inches 
in diameter. 
