Figure 32. Typical method of providing 

 a high-pressure vent connec- 

 tion from the interior of a 

 specimen assembly. 



water-filled specimen to tine atmosphere 

 also served to permit the specimen to 

 fail by cracking or to implode without 

 the potentially damaging shock which 

 results from the implosion of a void or 

 even partially void specimen. 



Table 5 summarizes the results 

 of these experiments. 



From the viewpoint of simplicity 

 and low cost, the fiber-reinforced neo- 

 prene gasket (system 2) is the most 

 satisfactory to depths of 6,000 feet. 

 The systems which promise to give the 

 8,000-foot depth ratings for cyclical 

 service are 3 and 6, which utilize Vespel 

 and aluminum gaskets, respectively, to 

 eliminate failure from the rubbing of 

 the glass pipe end flanges on the end 

 closure as the glass pipe changes in 

 diameter with changes of external 

 pressure. 



Phase III: Prototype Housing Tests 



In order to demonstrate typical 

 applications of glass pipe to undersea 

 use, two prototype housing designs 

 were tested, one for a 1 ,000-watt light 

 and one for an instrument housing. 



Light Housing. Figure 33 shows a deep-submergence light specifically 

 developed to utilize a glass pipe housing with conical flanges. This design 

 utilizes a 1-1/2-inch-ID x 6-inch-iong, flanged Pyrex pipe as the transparent 

 section. Figure 34 shows the construction. 



Operational testing of this assembly indicated a collapse pressure of 

 9,000 psi. It was subsequently successfully operated and pressure cycled at 

 2,500 psi. In view of its successful performance at 2,500 psi, it is considered 

 reliable for operation at 5,000 feet. 



Instrument Housing. Figures 35 and 36 show a prototype instrument 

 housing developed at NCEL. This housing utilizes two 4-inch-ID, flanged 

 Pyrex glass pipe caps and a section of 4-inch-ID, flanged Pyrex glass pipe 



30 



