Journal of Failure Analysis and Prevention

, Volume 15, Issue 3, pp 417–423 | Cite as

Validation of a Leak-Before-Break Criterion Using Limit Load Solution

  • P. Kannan
  • K. S. Amirthagadeswaran
  • T. Christopher
Technical Article---Peer-Reviewed


The assessment of risk of crack-like defects in pipes and pressure vessels is a challenging task for the power plant operator and the designer. Leak-Before-Break phenomenon is an important requirement for the safe design and re-assessment of pressure vessels. In this paper, early basic concepts have been verified with the available literature test data and the reason for their non-compliance has been discussed. In order to predict the leak and break behavior of the crack in a cylindrical pressure vessel or pipe, a simple limit load solution is utilized. Using the limit load solution, failure boundary is successfully created for cylindrical vessel made of high-strength steels including 4134 V steel and 4130 X steel. The boundary distinctly separates the leak and break cases. It is a handy tool for the operator or designer of the Nuclear and Thermal Power Plants to check the fitness of the cracked pressure vessels or pipes.


Leak-Before-Break (LBB) Limit load LBB criterion Pressure vessel Steel cylinders Surface crack 


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Copyright information

© ASM International 2015

Authors and Affiliations

  • P. Kannan
    • 1
  • K. S. Amirthagadeswaran
    • 2
  • T. Christopher
    • 3
  1. 1.Ramagundam Super Thermal Power StationNTPC Ltd.RamagundamIndia
  2. 2.Faculty of Mechanical EngineeringGovernment College of TechnologyCoimbatoreIndia
  3. 3.Faculty of Mechanical EngineeringGovernment College of EngineeringTirunelveliIndia

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