NDT procedures are the foundation of every inspection program. A well-written procedure ensures consistent, repeatable, and code-compliant inspections. A poorly written one leads to rejected reports, audit findings, and—in worst cases—missed defects that compromise safety.
\nThis guide provides a practical framework for writing NDT procedures that satisfy ASME Section V, API standards, and client specifications.
\n\nUnder most qualification schemes (SNT-TC-1A, CP-189, ISO 9712), the Level III is responsible for:
\nEven if Level II technicians draft procedures, Level III review and approval is required for code compliance.
\n\nASME Section V is the primary NDT code for pressure equipment. It establishes two types of documents:
\n\nA detailed document specifying all parameters and steps for performing a specific NDT examination. Must address all "essential variables" and "nonessential variables" defined in the applicable article.
\n\nA supplementary document that captures job-specific parameters within the framework of an approved procedure. Technique sheets allow one procedure to cover multiple applications.
\n\nClearly define what the procedure covers: the NDT method, material types, product forms, thickness ranges, and applicable code editions. Be specific—vague scope statements are a common audit finding.
\n\nList all referenced codes, standards, and specifications with edition dates. Common references include:
\nSpecify minimum certification levels required to perform and evaluate examinations. Reference the qualification standard (SNT-TC-1A, CP-189, or ISO 9712) and any additional client or regulatory requirements.
\n\nDocument all equipment required with sufficient detail for verification:
\nDefine required surface condition, cleaning methods, and temperature requirements. Specify acceptance criteria for surface preparation and any limitations on surface condition.
\n\nDetail the complete calibration procedure including:
\nThis is the core of the procedure. Describe the examination methodology in sufficient detail that a qualified technician can perform the examination consistently. Include:
\nReference the specific acceptance criteria from the construction or inspection code. Do not paraphrase acceptance criteria—reference the code section directly or reproduce it exactly. Incorrect or ambiguous acceptance criteria are a leading cause of report rejections.
\n\nSpecify report format, required information, record retention requirements, and data recording methods. Reference any standard report forms to be used.
\n\nList all essential variables as defined by the applicable ASME Section V article. Essential variable changes require procedure re-qualification; nonessential variable changes require only procedure revision.
\n\nASME Section V requires that NDT procedures be demonstrated (qualified) before use. Demonstration requirements include:
\nSome client specifications require blind demonstration using samples with known defects.
\n\nBased on Level III consulting experience, the most frequent procedure deficiencies include:
\nUT procedures require particular attention to search unit selection, scanning sensitivity, distance-amplitude correction, transfer correction, and coverage documentation. ASME V Articles 4 and 5 have different requirements for welds vs. materials.
\n\nRT procedures must address source selection, geometric unsharpness calculations, exposure techniques, IQI selection and placement, and radiographic density requirements. Safety and regulatory compliance sections are essential.
\n\nSurface methods require careful attention to surface preparation, temperature limitations, dwell times, lighting requirements, and post-examination cleaning. Process control verification steps are critical.
\n\nAtlantis NDT provides comprehensive procedure development and review services:
\nContact us for expert Level III procedure development and review services.
","author":"Atlantis NDT","order":0,"createdAt":"2026-03-15","updatedAt":"2026-10-18","metaDescription":"Step-by-step guide to writing ASME Section V compliant NDT procedures. Essential elements, common rejection causes, procedure qualification, and Level III best practices for 2026."}