o = 200,000 



R. = internal radius, in. 

 Rq = external radius, in. 

 a = tensile yield strength, psi 



Figure 2. Internal pressure capability of a cylindrical pressure vessel as 

 a function of its thickness-to-diameter ratio. 



the existing design concepts for large pressure vessels and selected the stacked- 

 ring and the segnnented-wall module concepts with tie-rod end-closure restraints 

 as the most promising candidates for future large-diameter, high-pressure vessels 

 and recommended their further study, preferably by experimental means. In 

 depth the study was limited only to a single conceptual design of each concept 

 under consideration. The two design concept models tested were to be made 

 only from one material, acrylic plastic. 



Besides the experimental evaluation of the two modular vessel design 

 concepts, one of four seal systems was to be experimentally evaluated for use 

 with large-diameter, high-pressure vessels of modular construction (Appendix B). 



