Pressure vessels for high pressure applications

Abstract

A pressure vessel is provided having a wall with an inner surface defining a chamber about an axis and an outer surface. The wall has a thickness with at least one vent hole therein located substantially parallel with the axis. The at least one hole is located a distance from the axis, the distance providing an outer thickness of the wall between the at least one hole and the outer surface sufficient to withstand a stress generated by pressure within the pressure vessel. An inner thickness of the wall between the at least one hole and the inner surface to permit a crack to propagate from the inner surface and connect with the hole causing venting of the pressure in the chamber.

What is claimed is:  
     
         1 . A pressure vessel having a wall with an inner surface defining a chamber about an axis and an outer surface, said wall having a thickness with at least one vent hole therein located substantially parallel with said axis; 
 said at least one hole being located a distance from said axis, said distance providing an outer thickness of said wall between said at least one hole and said outer surface sufficient to withstand a stress generated by pressure within said pressure vessel; and    an inner thickness of said wall between said at least one hole and said inner surface to permit a crack to propagate from said inner surface and connect with said hole causing venting of said pressure in said chamber.    
     
     
         2 . The pressure vessel according to  claim 1 , wherein said pressure vessel is of a ductile material and said stress is a yield stress of the material of the pressure vessel.  
     
     
         3 . The pressure vessel according to  claim 1 , wherein said pressure vessel is of a ductile material and said stress is an ultimate tensile stress of the material of the pressure vessel.  
     
     
         4 . The pressure vessel according to  claim 1 , wherein said pressure vessel is a cylinder having a first end face and a second end face and said at least one vent hole extends between and connects said first end face and said second end face.  
     
     
         5 . The pressure vessel according to  claim 4 , wherein said at least one vent hole is located at clocked positions around a cross-section of said wall.  
     
     
         6 . The pressure vessel according to  claim 4 , wherein said at least one vent hole comprises three vent holes spaced circumferentially around said wall.  
     
     
         7 . The pressure vessel according to  claim 4 , wherein said at least one vent hole comprises four vent holes spaced circumferentially around said wall.  
     
     
         8 . The pressure vessel according to  claim 1 , wherein said pressure vessel is a cylinder having a first end face and a second end face and further comprises at least one vent hole extending from said first end face toward but terminating before said second end face and at least one vent hole extending from said second end face toward but terminating before said first end face.  
     
     
         9 . The pressure vessel according to  claim 8 , wherein said at least one vent extending from said first end face and said at least one vent extending from said second end face are located at alternate clocked positions around a cross-section of said wall.  
     
     
         10 . The pressure vessel according to  claim 9 , wherein a portion of said at least one vent extending from said first end face and a portion of said at least one vent extending from said second end face overlap within said wall.  
     
     
         11 . The pressure vessel according to  claim 1 , wherein said pressure vessel is a thick walled pressure vessel.  
     
     
         12 . The pressure vessel according to  claim 11 , wherein said thick walled pressure vessel is selected from the group consisting of a plunger cylinder and an accumulator for high pressure intensifiers.  
     
     
         13 . A cylindrical pressure vessel having a wall with an inner cylindrical surface having a diameter (D I ) defining a chamber about a longitudinal axis and an outer cylindrical surface having a diameter (D o ), said wall having a thickness with at least one vent hole therein located substantially parallel with said axis; 
 said at least one hole being located along a cylindrical region in said thickness, said cylindrical region being concentric with said longitudinal axis and having a diameter (D v ) to provide an outer thickness of said wall between said at least one hole and said outer surface sufficient to withstand a stress generated by a pressure (p) within said pressure vessel; and    an inner thickness of said wall between said at least one hole and said inner surface to permit a crack to propagate from said inner surface and connect with said hole causing venting of said pressure in said chamber.    
     
     
         14 . The cylindrical pressure vessel according to  claim 13 , wherein said cylindrical pressure vessel is made of a ductile material having a yield stress (σ y ) and has at least one end having a bore with a diameter (d) and said maximum diameter (D v ) of said cylindrical pressure vessel is defined by the equation:  
       
         
           
             
               
                 D 
                 v 
               
               = 
               
                 
                   
                     ( 
                     
                       
                         
                           
                             σ 
                             y 
                           
                           · 
                           D 
                         
                          
                         
                             
                         
                          
                         
                           o 
                           2 
                         
                       
                       + 
                       
                         p 
                         · 
                         
                           d 
                           2 
                         
                       
                     
                     ) 
                   
                   
                     ( 
                     
                       
                         σ 
                         y 
                       
                       + 
                       p 
                     
                     ) 
                   
                 
               
             
           
           
           
               
           
         
       
     
     
         15 . The cylindrical pressure vessel according to  claim 14 , wherein said at least one vent hole is located at clocked positions around a cross-section of said wall.  
     
     
         16 . The cylindrical pressure vessel according to  claim 14 , wherein said cylindrical pressure vessel has a first end face and a second end face and further comprises at least one vent hole extending from said first end face toward but terminating before said second end face and at least one vent hole extending from said second end face toward but terminating before said first end face.  
     
     
         17 . The cylindrical pressure vessel according to  claim 16 , wherein said at least one vent extending from said first end face and said at least one vent extending from said second end face are located at alternate clocked positions around a cross section of said wall.  
     
     
         18 . The cylindrical pressure vessel according to  claim 13 , wherein said cylindrical pressure vessel is made of a ductile material having an ultimate tensile stress (σ t ) and has at least one end having a bore with a diameter (d) and said maximum diameter (D v ) of said cylindrical pressure vessel is defined by the equation:  
       
         
           
             
               
                 D 
                 v 
               
               = 
               
                 
                   
                     ( 
                     
                       
                         
                           
                             σ 
                             t 
                           
                           · 
                           D 
                         
                          
                         
                             
                         
                          
                         
                           o 
                           2 
                         
                       
                       + 
                       
                         p 
                         · 
                         
                           d 
                           2 
                         
                       
                     
                     ) 
                   
                   
                     ( 
                     
                       
                         σ 
                         t 
                       
                       + 
                       p 
                     
                     ) 
                   
                 
               
             
           
           
           
               
           
         
       
     
     
         19 . The cylindrical pressure vessel according to  claim 18 , wherein said cylindrical pressure vessel has a first end face and a second end face and further comprises at least one vent hole extending from said first end face toward but terminating before said second end face and at least one vent hole extending from said second end face toward but terminating before said first end face.  
     
     
         20 . The cylindrical pressure vessel according to  claim 19 , wherein said at least one vent extending from said first end face and said at least one vent extending from said second end face are located at alternate clocked positions around a cross-section of said wall.