An NDE procedure is the document that governs how a specific non-destructive examination is performed on a specific type of component. It defines the technique, equipment, calibration method, scanning patterns, acceptance criteria, and reporting requirements. When a procedure is wrong, everything that follows is wrong.
Under ASNT SNT-TC-1A and most applicable ASME codes, NDE procedures must be reviewed and approved by an ASNT NDT Level III certified in the applicable method. This is a code requirement, not a recommendation. This article explains what that review involves, why it matters, and what happens when it is skipped or done inadequately.
What ASNT SNT-TC-1A Requires
ASNT SNT-TC-1A is the recommended practice for personnel qualification and certification in nondestructive testing. Most companies adopt it as their written practice for NDT personnel qualification. Under SNT-TC-1A, the employer is responsible for the qualification and certification of NDT personnel, and the written practice governing that program must be approved by an ASNT Level III.
For procedure qualification specifically, ASME Section V Article 1 requires that all written NDT procedures be qualified and demonstrated to be capable of detecting the required discontinuity type and size. The Level III review is the technical authority that confirms the procedure meets the applicable code requirements before inspection work begins.
In practice, this means that a UT procedure for weld inspection on a pressure vessel, for example, must be reviewed by an ASNT Level III UT before that procedure is used in production. An ASNT Level III UT has demonstrated through examination that they have the technical knowledge to evaluate whether the procedure is appropriate for the application.
What a Level III Review Checks
A competent Level III procedure review is not a signature and a date. It is a technical evaluation of every element of the procedure against the applicable code or standard. The review covers:
- -Scope and applicability: Whether the procedure's stated scope actually covers the material, component type, thickness range, and weld geometry being inspected.
- -Technique selection: Whether the specified technique (angle, frequency, search unit size, scan pattern) is appropriate for the expected defect type and orientation. A straight beam UT procedure used to inspect for lack of fusion in a weld, for example, would be technically incorrect.
- -Equipment specifications: Whether the instrument, transducer, and couplant specifications are appropriate and whether there are any exclusions that could create detection gaps.
- -Calibration requirements: Whether the calibration block, calibration reflectors, and calibration frequency are consistent with the applicable code. Using the wrong reference block for ASME Section V calibration is a common procedure deficiency.
- -Scanning coverage: Whether the scanning pattern as specified actually achieves full volumetric coverage of the weld and heat-affected zone, including all required scan directions for the applicable weld geometry.
- -Acceptance criteria: Whether the acceptance criteria reference the correct code edition and division, and whether they are expressed in a way that can be applied unambiguously in the field.
- -Reporting requirements: Whether the report format captures all information required by the code including the procedure number and revision used, calibration records, and equipment serial numbers.
Common Procedure Deficiencies Found in Review
Based on reviewing procedures across a range of companies and project types, the following deficiencies appear most frequently:
- -Incorrect calibration block: Referencing a calibration block that does not match the material and thickness range being inspected. ASME Section V has specific requirements for calibration block material, reflector type, and block size.
- -Missing scan directions: Procedures that specify scanning in one direction only when the weld geometry and defect orientation require scanning from multiple directions for adequate coverage.
- -Technique inadequate for defect type: Specifying contact pulse-echo UT for a joint configuration where the expected defect orientation would not be detected by that technique. This is common in procedures written generically and applied to specific joints without adaptation.
- -Outdated code references: Procedures that reference superseded code editions or case numbers. When an operating facility is regulated under a specific code edition, the procedure must align with that edition.
- -Acceptance criteria ambiguity: Acceptance criteria written in a way that allows different inspectors to reach different accept/reject decisions on the same indication. This creates inconsistency across inspection campaigns and complicates trending.
- -Missing personnel qualification requirement: Procedures that do not specify the minimum Level certification and method required for the inspection, or that allow Level I personnel to perform examinations that require Level II under the applicable code.
Consequences of Inadequate Procedures
Operating with an inadequate NDE procedure has real consequences that go beyond paperwork deficiencies:
Detection failure: If the technique specified is not capable of detecting the actual defect type, defects will be missed. A procedure that looks compliant on paper but is technically incorrect for the application provides false assurance. The most serious consequence of an inadequate procedure is a missed defect in a critical component.
Regulatory and code non-compliance: For ASME-coded pressure equipment, using a procedure that does not meet ASME Section V requirements is a code non-conformance. During an ABSA audit or ASME audit, inadequate procedures will generate findings. Resolving those findings after the fact typically requires re-inspection of completed work.
Legal exposure: If a component fails after inspection performed under an inadequate procedure, the inadequate procedure is evidence of a quality failure in the inspection program. This exposes both the fabricator and the inspection company to liability.
Project delays: Procedure deficiencies found during owner or third-party review before work starts can be resolved quickly. The same deficiency found by a regulator after work is complete triggers rework, re-inspection, and potential rejection of completed weldments.
Procedure reviews identified before work starts are inexpensive to resolve. The same deficiency found post-inspection can require re-inspection of an entire weld campaign.
When to Engage an External Level III
Many fabricators and inspection companies do not have an in-house ASNT Level III. They rely on contractors or on personnel who hold Level II credentials but not Level III authority. In these cases, procedures are sometimes approved by supervisors who do not hold the required qualification, or they are simply filed without proper review.
External Level III engagement is appropriate in several situations: when a company does not have an in-house Level III certified in the required method; when a new procedure is being written for an application not previously covered; when an existing procedure is being used on a new material, geometry, or code basis; when a client or regulator requires Level III review and approval documentation; or when preparing an NDT program for a major project or turnaround where procedure quality needs to be verified before field work begins.
Norman QC provides ASNT Level III procedure review, development, and approval services for UT, RT, MT, PT, and VT. For scope and fee information, contact via the contact page.
How ANAB Accreditation Adds Verification
An ANAB-accredited inspection body is required to maintain and follow documented NDT procedures as part of its quality management system. ANAB assessors review these procedures during assessments. This provides an additional layer of verification beyond the Level III review: the accreditation body has independently confirmed that the inspection body's procedures are in place and are being followed.
For clients who specify ANAB-accredited inspection, this means procedure quality has been assessed not just by the inspection body's own Level III, but by an external accreditation body with oversight authority. This is the highest level of third-party verification available for NDE procedure quality.
FAQs
Is a Level III review required by ASME codes for all NDE?
ASME Section V requires that written NDE procedures be established and qualified. The requirement for Level III review and approval is established by ASNT SNT-TC-1A (adopted in the employer's written practice) and referenced in the ASME Boiler and Pressure Vessel Code. For most pressure equipment inspection under ASME, Level III approval of written procedures is a code requirement.
Can a Level II certified inspector write an NDE procedure?
An ASNT Level II certified individual can perform and direct NDE and can set up calibrations. They cannot approve NDE procedures for use. Procedure approval authority under SNT-TC-1A is held by Level III certified personnel. A Level II may draft a procedure, but it requires Level III review and approval to be put into production use.
How often should NDE procedures be reviewed?
Procedures should be reviewed whenever there is a change in the applicable code or standard, a change in the technique or equipment, or extension of the procedure to new materials, thicknesses, or geometries. At minimum, an annual review to confirm currency with the applicable code edition is good practice.
Can the procedure review be done remotely?
Yes. Procedure review is a document review activity that does not require on-site presence. Procedures can be submitted electronically, reviewed against the applicable codes and standards, and returned with a signed review report documenting findings and approval status. This is one of the services Norman QC provides remotely.