flange section 

 of 4-inch-IDx 

 6-inch-long 

 Pyrex glass 

 pipe 



1/4-inch- 

 ^^^ thick soft 



Figure 30. Experimental sealing and 

 bearing systenn utilizing 

 a 1/4-inch-tliicl< captive 

 neoprene washer between 

 the glass pipe end flange 

 and the metal end-closure 

 plate. 



Each specimen assembly of the 

 eight different systems described above 

 was filled with water and the specimen 

 vented through a high-pressure connec- 

 tion (Figures 31 and 32) to a sight 

 glass (outside the vessel) at atmospheric 

 pressure. This enabled the observer to 

 detect any minor leaks in the assembly 

 which might otherwise go undetected 

 until the specimen was removed from 

 the vessel (assuming it was intact) on 

 completion of the series of tests. Pre- 

 vious e.xperience with cycling tests of 

 glass specimens in which the glass 

 cracked but did not fail violently 

 indicated the desirability of a leak 

 detector to determine precisely when 

 a leak occurred. This high-pressure 

 connection from the interior of the 



Figure 31. End-closure plates used in testing the Vespel and the neoprene 

 washers (shown here). The high-pressure vent is utilized in the 

 experimental measurement of internal volume change and for 

 attenuation of implosion force. 



29 



