Inquiry & Scope Definition
Submit via Inquiry & Quotation or inspection@guardian.qa. Define methods, codes, sample size, location, and timeline.
01NDT Inspection (Non-Destructive Testing)
Accreditation Chain
Issuing Inspection Body: TNV Global Limited. Accreditation: UAF — Inspection Body Certificate 5241222IB04. Validity: 28 December 2024 – 27 December 2028. Standard: ISO/IEC 17020:2012 (Type A — third-party independent). Local representation in Qatar: Guardian Middle East LLC (QFC Licence 03870). The accreditation framework explains the TNV inspection body role and Guardian’s local representation in Qatar.
NDT inspection reports are issued under TNV Global Limited’s name and UAF-accredited mark. Review the full Inspection Services pillar for the full accreditation framework, partnership model, and engagement model that governs all inspection scopes.
NDT Methods Covered
Guardian’s NDT inspection covers the principal volumetric and surface methods. Method selection is driven by the inspection requirement (defect type, material, accessibility, code reference) — typically defined in the project Inspection and Test Plan (ITP) or applicable code.
| Method | What It Detects | Application & Standards |
|---|---|---|
| RT – Radiographic | Internal defects, including porosity, slag, lack of fusion, and cracks. Volumetric method. | Used for welds in pressure equipment, piping, and structural connections. Applicable references include ASME V Article 2, ISO 17636-1 for X-ray, and ISO 17636-2 for digital radiography. Industrial radiography licensing requirements apply in Qatar; Guardian / TNV operates under licence-aligned protocols. |
| UT – Ultrasonic | Internal defects, including cracks, lack of fusion, laminations, and thickness-related conditions. Volumetric method. | Used for welds, plates, forgings, and in-service equipment. Applicable references include ASME V Article 4 for welds, Article 5 for materials, ISO 17640 for welds, and ISO 16811 for calibration. Includes conventional pulse-echo, time-of-flight diffraction (TOFD), and phased-array (PAUT) where commissioned. |
| MT – Magnetic Particle | Surface and near-surface defects in ferromagnetic materials. | Used for welds, castings, forgings, and in-service ferromagnetic equipment. Applicable references include ASME V Article 7, ISO 17638 for welds, and the ISO 9934 series covering general principles, equipment, and media. |
| PT – Liquid Penetrant | Surface-breaking defects in non-porous materials, across any suitable material type. | Used for welds, machined surfaces, castings, forgings, and other non-porous materials. Applicable references include ASME V Article 6 and the ISO 3452 series covering general principles, materials, technique, and leak testing. |
| VT – Visual | Surface defects, geometric deviations, and dimensional non-conformity. | Visual inspection underpins welding inspection and many fabrication contexts. Applicable references include ASME V Article 9 and ISO 17637 for welds. Covers direct visual, remote visual, and translucent visual variants. Often used as the entry-point inspection method, with other methods escalating from VT findings. |
Multi-method engagements are typical — for example, RT + UT for weld volumetric inspection; MT + UT for surface and volumetric inspection of ferromagnetic welds. The applicable code typically specifies the methods, the extent of inspection (sample %, 100%), and acceptance criteria.
Inspector Certification Levels
NDT inspectors operate under formal certification frameworks that define the depth of competence, the supervision relationship, and the authority to interpret results. Two principal frameworks apply:
ASNT Framework
- ASNT SNT-TC-1A — Recommended Practice for Personnel Qualification and Certification in Nondestructive Testing — employer-certified scheme widely used in US and US-aligned codes (ASME, AWS).
- ASNT CP-189 — Standard for Qualification and Certification of Nondestructive Testing Personnel — more prescriptive than SNT-TC-1A.
- ASNT Central Certification Program (ACCP) — third-party-certified scheme.
ISO 9712 Framework
- ISO 9712 — Non-destructive testing — Qualification and certification of NDT personnel — third-party certification scheme used in European, Asian, and increasingly international applications.
- Recognized under accreditation by certification bodies operating personnel certification schemes (ISO/IEC 17024).
Certification Levels
| Level | Authority & Responsibility |
|---|---|
| Level I | Trained to carry out specific calibrations, specific tests, and specific evaluations under written instruction. Cannot independently select method, technique, or interpret results; works under Level II or Level III supervision. |
| Level II | Qualified to set up and calibrate equipment, conduct tests, interpret and evaluate results against codes and standards, prepare written instructions, and report results. Cannot supervise method authority or write procedures, as those are Level III responsibilities. |
| Level III | Qualified to develop, qualify, and approve NDT procedures, interpret results against codes, standards, and specifications including ambiguous cases, designate inspection methods, train and examine Level I / II personnel, and provide technical authority on the method. |
Inspector deployment is matched to the engagement requirement. Routine inspection typically uses Level II inspectors; complex / first-of-kind / qualification activities involve Level III oversight. Inspector qualifications and certification copies are provided to clients on request.
Engagement Model
NDT inspection follows the standard 5-step engagement model documented in /inspection/ §16:
Contract & Inspection Plan
Contract executed; NDT plan agreed, including procedures, calibrations, equipment, personnel levels, CDD / EDD, and inspector COI declarations.
02On-site Inspection
Inspector or inspection team deployed with required equipment. Calibration is verified on-site and testing is conducted per approved procedures.
03Inspection Report
Issued under TNV Global Limited's UAF-accredited mark. Includes method reports, indication maps, sketches or radiographs, and acceptance / rejection statements.
04Follow-up Activities
Re-testing of repaired areas, periodic inspection, and regulatory liaison completed as commissioned.
05NDT-Specific Procedural Requirements
- Approved procedures — NDT activity is conducted under written procedures approved at Level III. Procedures reference the applicable code/standard and define equipment, calibration, technique, scanning patterns, evaluation, and reporting.
- Calibration verification — equipment is calibrated and verified on-site before testing. Calibration records form part of the inspection record.
- Reference standards / blocks — applicable reference blocks (ultrasonic) or image quality indicators (radiographic) are used to verify technique sensitivity.
- Radiation safety — for radiographic testing, applicable Qatar radiation safety requirements are observed; radiographers operate under licence-aligned protocols. Site-specific radiation safety planning is required prior to RT activities.
Standards & Codes Framework
| Standard / Code | Application |
|---|---|
| ASME Section V | Non-destructive Examination within ASME Boiler and Pressure Vessel Code. The dominant US code for NDT in pressure equipment, piping, and related applications. Includes Article 2 for RT, Article 4 for UT welds, Article 5 for UT materials, Article 6 for PT, Article 7 for MT, and Article 9 for VT. |
| ASNT SNT-TC-1A | Recommended Practice for Personnel Qualification and Certification in Nondestructive Testing, used as an employer-certified scheme. |
| ASNT CP-189 | Standard for Qualification and Certification of Nondestructive Testing Personnel, used as a more prescriptive personnel qualification variant. |
| ISO 9712 | NDT qualification and certification of NDT personnel. A third-party-certified scheme commonly used in European and international projects. |
| ISO 17636 series | Radiographic testing of welds. Part 1 covers X-ray and gamma-ray techniques with film. Part 2 covers digital detector techniques. |
| ISO 17640 | Ultrasonic testing of welds, including techniques, testing levels, and assessment. |
| ISO 17638 | Magnetic particle testing of welds. |
| ISO 3452 series | Penetrant testing. Covers general principles, testing of penetrant materials, reference test blocks, and equipment. |
| ISO 17637 | Visual testing of welds, including direct, remote, and translucent visual testing variants. |
| API 1104 / API 510 / API 570 | Sector-specific codes that reference NDT for pipeline welding, pressure vessel inspection, and piping inspection respectively. |
| AWS D1.1 / D1.2 / D1.6 | Structural welding codes that reference specific NDT requirements for weld acceptance. |
Typical Use Cases
- Weld inspection (multi-method) — RT and/or UT for volumetric weld inspection; MT or PT for surface; VT throughout. Common in pressure equipment, piping, structural fabrication.
- Pressure vessel manufacturing inspection — inspection of welds, materials, and forgings during pressure vessel fabrication, aligned with ASME VIII and ASME V. This connects with the ASME V/VIII context for pressure equipment.
- In-service equipment inspection — UT thickness measurement of pressure vessels, piping; MT/PT for in-service weld inspection; periodic NDT campaigns.
- Pipeline construction inspection — RT of girth welds, UT of seam welds, integrated with API 1104 acceptance criteria. Pipeline NDT often follows API 1104 / API 570 NDT context.
- Structural steel inspection — UT of complete-joint-penetration welds in critical structural applications under AWS D1.1.
- Forgings and casting inspection — UT, MT, PT of new components against material specifications.
- Damage/integrity assessment — UT, MT, PT of in-service equipment to assess service-induced degradation, integrated with fitness-for-service evaluations.
- Pre-shipment / FAT NDT witness — third-party NDT witness for items being shipped, supporting buyer / end-user verification. Buyer-side verification can include pre-shipment NDT witness before release.
Why Choose Guardian for NDT
- UAF-accredited reports under TNV Global Limited’s Inspection Body Cert 5241222IB04 — internationally recognized under the IAF MLA Inspection arrangement.
- Type A independence — third-party independent classification under ISO/IEC 17020:2012.
- Multi-method capability — RT, UT (including TOFD/PAUT where commissioned), MT, PT, VT — covered through certified inspectors and approved procedures.
- Multi-framework certification — inspectors certified to ASNT SNT-TC-1A, CP-189, and ISO 9712 frameworks at Levels I, II, and III.
- Code-aligned competence — ASME V, ISO method standards, AWS, API integrated into inspector deployment.
- Local Qatar presence — Guardian Middle East LLC operates as a QFC-licensed firm with on-the-ground capability.
- Integrated welding + NDT capability — see /inspection/welding-inspection/ — common combined scope for project lifecycle support. NDT is often paired with welding inspection — typical companion scope.
- Absolute non-consultancy commitment — preserves the integrity and stakeholder value of the inspection report.
GET STARTED — CONTACT GUARDIAN
Guardian Middle East LLC | Serving the Middle East
QFC Licence 03870 · Doha, Qatar
Location: Abo Hamour Area, Doha, Qatar
P.O. Box: 23277, Doha, Qatar
Mobile: +974 7770 2602 | +974 7213 7770
Email: info@guardian.qa
Website: www.guardian.qa
Or submit an enquiry: → Contact
Compliance Notes
NDT inspection services are delivered under TNV Global Limited’s UAF-Accredited Inspection Body Certificate 5241222IB04 (valid 28 December 2024 – 27 December 2028) under ISO/IEC 17020:2012 (Type A — third-party independent). Guardian Middle East LLC is the local representative in Qatar (QFC Licence 03870). Inspection reports are issued under TNV’s UAF-accredited mark and are recognised under the IAF MLA Inspection arrangement where applicable. NDT methods covered: Radiographic Testing (RT), Ultrasonic Testing (UT) including TOFD/PAUT where commissioned, Magnetic Particle Testing (MT), Liquid Penetrant Testing (PT), Visual Testing (VT). Inspector certification frameworks: ASNT SNT-TC-1A, ASNT CP-189, ISO 9712 — Levels I, II, and III. Standards aligned: ASME Section V; ISO 17636/17640/17638/3452/17637; AWS, API, and other code references as applicable. Industrial radiography activities operate under licence-aligned radiation safety protocols. Activities operate under the impartiality framework (ISO/IEC 17020:2012 §4.1), confidentiality framework (§4.2), and an absolute non-consultancy commitment.
Frequently Asked Questions
Method selection depends on the defect type, material, accessibility, and code reference. RT and UT are volumetric (detect internal defects). MT and PT are surface methods. VT is the entry-point method underpinning others. The applicable code typically specifies methods. For project-specific selection, define the inspection requirement (what defect / what material / what code) — Guardian's quotation will reference appropriate methods.
Level II inspectors set up equipment, conduct tests, interpret results against codes, and report. Level III inspectors develop and approve NDT procedures, designate methods, train and examine Level I/II personnel, and provide method authority. Most routine inspection uses Level II inspectors; complex or first-of-kind activities involve Level III oversight.
Depends on the code/specification. ASME-aligned projects typically reference ASNT SNT-TC-1A or CP-189. European-specification projects typically reference ISO 9712. Many international projects accept both. The inspection plan agreed at Step 2 identifies the governing framework.
Yes — Time-of-Flight Diffraction (TOFD) and Phased-Array Ultrasonic Testing (PAUT) are available where commissioned. These advanced techniques are particularly valuable for complex welds, weld root inspection, and applications where conventional pulse-echo UT has limitations. Equipment availability and operator certification are confirmed at quotation stage.
Radiographic Testing involves ionising radiation (X-ray or gamma-ray sources). Industrial radiography in Qatar requires applicable licensing and authorisation. Guardian / TNV operate under licence-aligned protocols including site-specific radiation safety planning, exclusion zones, dosimetry, and source security. RT activities are pre-planned with the client to ensure site safety.
NDT is predominantly an on-site activity — equipment is portable and inspection is conducted at the location of the item under test. Some specialist applications (e.g., specific automated UT setups, high-resolution radiography) may require laboratory environments. Guardian's NDT inspection is typically on-site; site-specific equipment requirements are confirmed at the inspection plan stage.
NDT inspection results in indications that are evaluated against acceptance criteria from the applicable code/standard/specification. The output is an objective statement of conformity or non-conformity — backed by indication records, calibration evidence, and procedural records. We do not provide a colloquial 'pass' / 'fail' — we provide an inspection report with code-referenced acceptance/rejection per indication.
No. Guardian and TNV operate under an absolute non-consultancy commitment. Our inspectors will identify indications, classify them against the applicable code, and report acceptance or rejection clearly. We will not design repair procedures, recommend specific corrective approaches, or supervise repair welding. If you need repair-procedure support, engage an independent welding/integrity consultant outside the Guardian engagement.
Yes — procedure qualification is a distinct activity. Guardian's Level III inspectors can review, witness qualification of, and endorse client NDT procedures against applicable codes. Procedure qualification is conducted under defined witnessing protocols and is documented in the resulting Procedure Qualification Record.
Submit an inquiry via /process/inquiry-and-quotation/ — selecting 'Inspection Services' as engagement type and 'NDT' as scope. Or email inspection@guardian.qa with project details: NDT methods required, applicable code, sample / extent, project location, indicative timeline. Specific information helps us match inspector qualification and equipment to your needs.