Figure 20. Assembled segmented end-closure retaining flanges. 



Testing 



Stacked Ring. The stacked-ring pressure vessel was tested with 

 internally applied hydrostatic pressure generated by positive-displacement 

 air-operated pumps. The pressurizing medium was tap water at 65°F. The 

 testing of the stacked-ring pressure vessel was conducted in three distinct 

 steps that were dictated by failure of various structural components at different 

 pressure levels. The first test consisted of pressurizing the vessel at a rate of 

 100 psi/minute (Figure 22) until at 380 psi the test was terminated by fragmen- 

 tation of the hemispherical end closure. During the test, strain readings were 

 taken at 100-psi intervals (Figure 23). 



The second test consisted of pressurizing the vessel until the tie rods 

 failed in tension at the base of their heads at 400 psi. For this test the hemi- 

 spherical end closures were replaced with 2-inch-thick flat aluminum discs that 

 fitted the interior dimensions of the acrylic end-closure retaining ring. Because 

 of this, no change in strain distribution took place in the end-closure retaining 

 ring or the rods (Figure 24). 



The third test consisted of placing the stack of rings between flat steel 

 end closures held together by steel tie rods. When the interior of this vessel was 

 pressurized, the failure of one of the rings took place at 1,200 psi (Figure 25). 



27 



