Method and apparatus for providing leak-before-burst failure of a pressurized component

Abstract

In a pressure vessel, pressure fitting, or pressure component, service use may result in the propagation of fatigue cracks. According to embodiments, a leak channel may be designed and formed to cause a pressurized fluid nominally contained by the pressure member to leak after formation of a fatigue crack, rather than undergoing a more catastrophic burst failure. According to an embodiment, a method is taught for determining the propensity of fatigue cracks to form, determining the location of the possible fatigue cracks, and determining a location for a leak channel, leak hole, weep hole, etc. for preventing burst failure. According to an embodiment, a computer program performs steps to design leak channels for prevention of burst failures in favor of leak-before-burst (LBB) failures.

1. A method for designing a pressure member having a leak-before-burst mode of failure, comprising:
 determining a crack propagation path in a pressure member; and  
 determining a leak channel location that intersects the crack propagation path.  
 
   
   
     2. A method for fabricating a pressure member having a leak-before-burst mode of failure, comprising:
 fabricating a pressure member having a potential crack propagation path; and  
 forming in the pressure member a leak channel that intersects the potential crack propagation path.  
 
   
   
     3. A pressure member having a leak-before-burst mode of failure, comprising:
 a pressure member wall having at least one potential crack propagation path; and  
 a leak channel formed in the pressure member wall in a location that intercepts the potential crack propagation path.  
 
   
   
     4. A computer-readable medium carrying computer instructions for carrying out the steps comprising:
 receiving a pressure-member geometry and material properties;  
 determining one or more possible fatigue crack propagation paths using LEFM analysis;  
 determining a leak channel that intersects the one or more possible fatigue crack propagation paths; and  
 performing stress analysis using FEA to verify that the designed leak channel does not increase stress concentration in the pressure member.