split nut 

 keeper 



Figure 7. Typical tie-rod end-closure restraint system. 



If industry can forge a flat retaining ring larger than the hemispherical 

 end closure, the latter can be modularized so that the factor limiting pressure 

 vessel size is the retaining ring forging, and not the end-closure forging. 



One modular design breaks the monolithic end closure down into many 

 spherical polygons permitting the assembly of the end closure from many small, 

 easily forgeable structural modules. Since welding or bolting those end-closure 

 modules would considerably reduce the capacity of such a modular end-closure 



11 



