NDT Test Reports: What Each Method Covers and What Must Be Documented

NDT test reports are the documented evidence that a component has been examined for flaws by non-destructive means and either accepted or rejected against defined acceptance criteria. In pressure equipment, structural, and pipeline fabrication, NDT reports are mandatory hold-point deliverables that must accompany the equipment data package.

Quick Answer

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Why NDT Reports Are Legally Significant

NDT reports are not internal quality notes. In code construction they are:

• Hold-point records required before post-weld heat treatment, pressure test, or release
• Legal deliverables required by Authorized Inspection Agencies (AIAs) for ASME code stamps
• Insurance documentation referenced in the event of a failure investigation
• Retention documents required for the life of the equipment under ASME BPVC

A missing or unsigned NDT report is a code violation, not a minor oversight.

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Method 1: Ultrasonic Testing (UT)

UT uses high-frequency sound waves transmitted into the material to detect internal discontinuities. The sound reflects off flaws and back-wall surfaces.

Detection capability: Internal inclusions, lack of fusion, cracks, laminations, wall thickness measurement

Governing standard: ASME V Article 4 (contact UT), ASME V Article 5 (immersion UT)

Required report fields:

• Procedure number and revision
• Equipment make, model, serial number
• Transducer(s): frequency, crystal size, angle
• Couplant used
• Calibration block reference (IIW block, basic calibration block)
• Scan pattern and coverage map
• Any indications found: location, amplitude (% FSH or dB), length, depth
• Acceptance criteria reference (e.g., ASME VIII UW-53, API 1104 Clause 9)
• Examiner name, certification level (ASNT SNT-TC-1A Level II), date
• Final disposition: Accept / Reject / Repair and Re-examine

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Method 2: Radiographic Testing (RT)

RT uses X-ray or gamma-ray radiation to produce an image of the component's interior on a radiographic film or digital detector.

Detection capability: Porosity, slag inclusions, lack of penetration, burn-through, cracks (planar flaws may be missed if beam angle is not optimized)

Governing standard: ASME V Article 2; AWS D1.1 Clause 8

Required report fields:

• Source type (X-ray kV, or gamma source: Ir-192, Co-60, Se-75) and source size (IQI)
• Source-to-film distance (SFD) and geometric unsharpness (Ug) calculation
• Film type (ASTM E1742) or detector type (digital)
• IQI (Image Quality Indicator) type and placement: ASME 2T hole type or wire type per SE-1025
• Exposure time, kV, mA (for X-ray)
• Density range achieved on film (2.0–4.0 ASTM E94)
• Film identification and location markers
• All indications: weld joint ID, location, type, dimensions
• Acceptance criteria: ASME VIII UW-51, AWS D1.1 Table 6.1, API 1104 Clause 9.6
• Interpreter name, Level II/III certification, date of interpretation

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Method 3: Magnetic Particle Testing (MT)

MT detects surface and near-surface discontinuities in ferromagnetic materials by applying a magnetic field and iron particles that cluster at flux leakage points.

Detection capability: Surface-breaking and near-surface cracks, seams, laps — ferromagnetic materials only (carbon steel, low-alloy steel, 400-series stainless)

Governing standard: ASME V Article 7; ASTM E709

Required report fields:

• Magnetization technique (yoke, prod, coil, central conductor)
• Yoke lift test result (≥ 4.5 kg for AC, 18 kg for DC per ASTM E709)
• Particle type: wet fluorescent, wet visible, dry
• Light level (UV-A intensity ≥ 1000 μW/cm² for fluorescent; white light ≥ 100 fc for visible)
• Surface condition and temperature
• Indication map with sketch or photo
• Acceptance criteria reference (ASME VIII Appendix 6, AWS D1.1 Clause 8.8)
• Examiner certification

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Method 4: Liquid Penetrant Testing (PT)

PT reveals surface-breaking discontinuities by capillary action of a dye penetrant that seeps into flaws and is drawn back to the surface by a developer.

Detection capability: Surface-breaking discontinuities only; applicable to both ferromagnetic and non-ferromagnetic materials (stainless steel, aluminum, titanium)

Governing standard: ASME V Article 6; ASTM E165

Required report fields:

• Penetrant system type: Type I (fluorescent) or Type II (visible); Method (solvent removable, water washable, post-emulsifiable)
• Dwell time, drain time, developer type and dwell time
• Light level (same requirements as MT)
• Surface temperature (4–52°C for standard method)
• Pre-cleaning method
• Indication map
• Acceptance criteria: ASME VIII Appendix 8, AWS D1.1 Clause 8.9

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Method 5: Phased Array Ultrasonic Testing (PAUT)

PAUT uses multiple ultrasonic elements fired in programmed time sequences to produce beam-steered scans and cross-sectional images (S-scans, B-scans, C-scans). It offers superior detection and characterization compared to conventional UT.

Detection capability: Same as UT but with full volumetric coverage, flaw sizing, and permanent electronic record

Governing standard: ASME V Article 4 Mandatory Appendix III; AWS D1.1 Clause 8.18 (UT); ASME Code Cases 2235, 2600

Required report fields (additional to UT):

• Instrument make/model with PAUT capability
• Probe array: number of elements, pitch, frequency, angle range
• Focal law file reference
• Calibration reference reflector (SDH, notch)
• S-scan and B-scan images archived to data file
• Data file name and storage location
• Sizing method (6 dB drop, TOFD, DLA)

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NDT Personnel Qualification

All NDT reports must identify the examining personnel and their certification level. The two dominant schemes:

Level II is the minimum required to independently perform and interpret examinations and issue reports. Level III certification is required to establish procedures and accept results for code construction.

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Digitizing NDT Records

Scanned PDFs of paper RT films and handwritten reports are the weakest form of record. They cannot be searched by weld joint ID, are easily lost, and provide no traceability between the indication and the equipment file.

Digital NDT records stored in quality management systems — such as TestCert — link each report to the specific weld joint, heat number, WPS, and inspection traveler, enabling instant retrieval during audits and eliminating the "where is the RT film for joint W-47?" scenario.

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