EXPERIMENTAL PROCEDURE 



In order to satisfy the objectives of the overall study, it was necessary 

 to embark on several phases or substudies. These were (Phase I) determination 

 of the relative critical pressure of various diameters and lengths of glass pipe, 

 (Phase II) determination of the best end-closure-to-glass bearing and sealing 

 system, and (Phase III) the testing of prototype light and instrument housings. 



Phase I: Short-Term Critical Pressure of Glassware 



Relative critical pressure was determined by preparing test assemblies 

 of four specimens of each selected diameter and length combination. Table 1 

 shows the dimensions and quantity of specimens evaluated in this first phase. 



Table 1 . Dimensions and Number of Specimens Tested 

 in Phase I of Study 



Inside 



Pipe Length* (in.) 



Diameter 

















(in.) 



6 



12 





18 





24 



36 















1 



4 



4 



















1-1/2 



4 



4 





4 





4 







2 



4 



4 





4 





4 



4 



3 



4 



4 





4 





4 



4 



4 



4 



4 





4 





4 



4 



6 



4 



4 





4 





4 



4 



Lengths of up to 120 inches are available. 



Figure 2 shows the component parts of a test assembly. Figure 3 

 shows one specimen of each length of 4-inch-ID pipe made up into a test 

 assembly and Figure 4 shows 6-inch lengths of five different diameters of 

 pipes made up into test assemblies. Due to the complete destruction of 

 the metal flange assemblies, which generally took place when the specimens 

 imploded, a simplified, less costly hold-down system was devised. This 



