Conclusions. The fabrication technique employing a compressed steel 

 liner and a pretensioned glass-fiber— epoxy laminate overwrap can produce a 

 10,000-psi internal working pressure vessel of 10-foot internal diameter and 

 20-foot length. Its low reliability and high cost place it at a disadvantage in 

 comparison to a pressure vessel of equal internal dimensions and pressure 

 capability fabricated by the multilayer or stacked-ring process. The cost of 

 the composite pressure vessel is estimated to be 3 to 5 times higher than for 

 a multilayer vessel. 



Recommendations. It is not recommended that this type of fabrication 

 be considered at the present time for the proposed NCEL vessel of 10-foot 

 internal diameter and 10,000-psi operating pressure. 



Tie-Rod Restraint 



Shear Restraint 

 Figure A-8. Typical end-closure restraints. 



END-CLOSURE RESTRAINT 

 SYSTEMS 



Restraints 



The following criteria apply 

 to the design of end-closure restraint 

 systems: 



1. The closure must accommodate 

 the forces exerted by the end caps 

 of a cylindrical vessel. 



2. A pressure-tight seal must be 

 incorporated. 



3. Comparatively simple and rapid 

 closure or opening of the vessel must 

 be possible. 



4. Penetrations through the closures 

 must be provided for transmission of 

 electric cables and hydraulic lines to 

 the vessel's interior during the tests. 



Three different end-closure 

 restraint systems are currently con- 

 sidered applicable to the deep-ocean 

 simulation vessels. The three different 

 systems are (Figure A-8): 



55 



