Process for installing liner in pressure vessel

Abstract

A process is disclosed for installing an elastomeric liner in a pressure vessel. The process comprises winding a tacky ribbon around an expandable mandrel, inserting it in the vessel shell, expanding the mandrel and optionally curing the wound ribbon.

What I claim and desire to protect by Letters Patent is: 
     
       1. A method of lining a small rocket motor case with elastomer, said method comprising: a. providing a shell for said case, said shell having a configuration including that of a cylinder;   b. providing a mandrel having a central axis and enclosed at least in part with an inflatable bladder, said mandrel and bladder adapted to fit within said shell;   c. providing an applicator for applying a thin, tacky ribbon that is continuous and comprises elastomer to the outer surface of said bladder;   d. affixing said ribbon to a first surface portion of said bladder;   e. causing relative rotation between said mandrel and said applicator around said central axis while moving said applicator along said central axis so as to adjacently position and tack together integral segments of said ribbon in geometric mating relation on the surface of said bladder whereby a layer of said elastomer is formed around said bladder, said layer of elastomer having dimensions generally corresponding to those required for the liner or portion thereof of said vessel;   f. placing within said shell said mandrel and said bladder having said layer of elastomer;   g. expanding said bladder by introducing pressurized gas to the inside of said mandrel so as to cause said layer of elastomer to contact the inside of said shell and to bond said shell together with said layer of elastomer as the liner or portion thereof for said case;   h. withdrawing said bladder from said layer of elastomer bonded to said shell;   i. withdrawing said mandrel and said bladder from the inside of said shell.   
     
     
       2. The method in accordance with claim 1, wherein said ribbon comprises curable elastomer. 
     
     
       3. The method in accordance with claim 1, wherein said curable elastomer is cured by heating said mandrel after expanding said bladder. 
     
     
       4. The method in accordance with claim 1, wherein the diameter of said rocket motor case is between about 5 and 50 cm. 
     
     
       5. The method in accordance with claim 1, wherein said bladder is expanded by means including creating a vacuum between said shell and said bladder having said elastomer layer. 
     
     
       6. The method in accordance with claim 1, wherein said ribbon comprises cured elastomer. 
     
     
       7. A method of lining a small rocket motor case with elastomer, said method comprising: a. providing a shell for said rocket motor case, said shell having a configuration including that of a dome shape;   b. providing a mandrel having a central axis and a dome shape, said central axis extending through the apex of said dome shape;   c. providing an inflatable mandrel that encloses said mandrel including around a portion of said dome shape;   d. providing an applicator for applying a thin, tacky ribbon that is continuous to the outer surface of said bladder;   e. affixing said ribbon to a first surface portion of said bladder;   f. causing relative rotation between said applicator and said mandrel about said central axis while moving said applicator along said central axis so as to adjacently position and tack together integral segments of said ribbon on said mandrel whereby a layer of said elastomer is formed around said bladder, said layer of elastomer having dimensions after cure substantially corresponding to those of the liner or portion thereof of said case;   g. placing within said shell said mandrel and said bladder having said layer;   h. expanding said bladder by introducing pressurized fluid to the inside of said mandrel so as to cause said layer to elastomer to contact the inside of said shell and bond said layer of elastomer and shell together;   i. curing said layer of elastomer;   j. withdrawing said bladder from said layer of elastomer bonded to said shell;   k. withdrawing said mandrel and said bladder from said shell.   
     
     
       8. The method in accordance with claim 7, wherein said mandrel comprises a dome structure and said central axis extends through the apex of said dome structure. 
     
     
       9. The method in accordance with claim 8, wherein there is an adapter which fits around the apex, said bladder enclosing said adapter as well.