Crack

A linear or branching discontinuity in material caused by stress concentration, thermal cycling, hydrogen embrittlement, or fatigue loading. Cracks are one of the most critical defect types as they can propagate rapidly under loading. Crack detection is a primary focus of NDT inspections, particularly in welds and high-stress components. Cracks must be sized and characterized to determine their fitness-for-service and repair requirements.

Detection and Assessment

Crack must be detected early and accurately characterized to determine safety implications. Multiple NDT methods may be required for comprehensive evaluation.

Acceptance Criteria

Industry standards such as ASME Section V, AWS D1.1, and API standards provide specific acceptance limits. Whether a detected crack is acceptable depends on material, component function, and applicable code.

Best Practices

• Always follow applicable NDT standards and procedures
• Use properly calibrated and maintained equipment
• Ensure personnel are properly trained and certified
• Document inspection procedures and results completely
• Keep current with industry standards and best practices