flange section 

 of 4-inch-IDx 

 6-inch-!ong 

 Pyrex glass 

 pipe 



0.025-inch-thick 

 fiber-reinforced 

 neoprene (Fairprene 

 5722A) washer with 

 silicone grease 



Figure 20. Experimental sealing and 

 bearing system utilizing a 

 fiber-reinforced neoprene 

 washer between the glass 

 pipe end flange and the 

 metal end-closure plate. 



ge section 

 of 4-inch-ID x 

 6-inch-Iong 

 Pyrex glass 

 pipe 



RTV silicone 



rubber (approx 



0.015-inch 



thick) 



Figure 21. Experimental sealing and 

 bearing system utilizing a 

 Vespel washer between the 

 glass pipe end flange and 

 the metal end-closure plate. 



dry lubricant material. Assembly was 

 effected by placing the molybdenum- 

 disulfide-coated face of a washer on 

 the steel end plate, placing the glass 

 pipe flange (coated with RTV silicone 

 rubber) in contact with the copper 

 face, then the second washer on the 

 opposite RTV silicone rubber coated 

 glass pipe flange (copper side down), 

 and finally placing the second steel 

 end plate on top of the washer. The 

 assembly was then compressed by 

 tightening the tie rods. The joints 

 between the washers and end plates 

 were then sealed with RTV silicone 

 rubber. (See Figure 22.) 



The purpose behind this system 

 (and those described in paragraphs 5, 

 6, 7, and 8) was to provide a bearing 

 surface (copper in this case) which 

 would be soft enough to accommodate 

 irregularities in the glass pipe end 

 flanges and thus effectively eliminate 

 stress concentrations due to point 

 loading at those areas. Figure 23 

 shows the relative indentations in 

 the aluminum (see paragraph 6), 

 copper, and lead (see paragraph 5) 

 bearing surfaces which resulted from 

 one pressure cycle to 3,000 psi. These 

 indentations give an indication of the 

 degree to which these materials 

 "accommodated" the configuration 

 of the glass bearing surface. In 

 addition, it was hoped that the glass 

 and washer assembly would respond 

 to changing external pressure as a 

 unit when changing diameter due to 

 the effects of such external hydro- 

 static pressure. The molybdenum 

 disulfide coating on the washer— end 

 closure contact area was provided to 



23 



