Discontinuity

Any break in the structural continuity of material, including internal (cracks, porosity, inclusions) and surface discontinuities. Not all discontinuities are defects; some are acceptable per applicable standards. Discontinuities must be detected, characterized, and evaluated to determine acceptability. The terms "discontinuity," "defect," and "flaw" are sometimes used interchangeably, though technically discontinuity is the broadest term.

Detection and Assessment

Discontinuity 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 discontinuity 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