I. INTRODUCTION TO ISO 3834 CERTIFICATION SERVICES
Fusion welding of metallic materials is a special process: weld quality cannot always be fully verified solely by final-product inspection without destroying or affecting the product. Quality therefore has to be built into the process, from the review of requirements, design, material selection and welding procedures to the control of personnel, equipment, inspection, testing and quality records.
The ISO 3834 series provides a systematic framework for controlling the quality of fusion welding of metallic materials in both workshop fabrication and field installation. ISO 3834 certification helps demonstrate a manufacturer's capability to organize and control welding activities within a defined technical scope.
ISO 3834 is independent of any specific product type and can be used in contracts, product standards, regulations or manufacturer-capability assessment schemes. It does not replace design requirements, weld acceptance criteria or statutory requirements applicable to the product, nor does it constitute a complete quality management system such as ISO 9001. It can, however, be applied independently or integrated into an existing quality management system.
The currently published editions of the core parts are ISO 3834-1:2021, ISO 3834-2:2021, ISO 3834-3:2021, ISO 3834-4:2021 and ISO 3834-5:2021. ISO 3834-1 provides criteria for selecting the appropriate level of quality requirements; ISO 3834-2, ISO 3834-3 or ISO 3834-4 provides the requirements used for certification assessment. ISO 3834-5 specifies the supporting standards or documents required to claim conformity.
Structure and purpose of ISO 3834-1, ISO 3834-2, ISO 3834-3 and ISO 3834-4
ISO 3834-1:2021
Provides an overview of the series and the criteria for selecting the appropriate level of quality requirements from ISO 3834-2, ISO 3834-3 and ISO 3834-4. Selection should take account of product and contractual requirements, safety significance, manufacturing complexity, product range, materials and the effect of welding imperfections on product performance.
ISO 3834-2:2021
Defines comprehensive controls for welding quality. It covers the review of requirements and technical review, subcontracting, personnel, equipment, production planning, WPS and WPQR/PQR, welding consumables, parent materials, post-weld heat treatment, inspection and testing, nonconformity, calibration and validation, identification, traceability and quality records.
ISO 3834-3:2021
Defines standard quality controls while retaining key technical elements such as requirements review, welding and welding coordination personnel, qualified welding procedures, suitable equipment, inspection, testing and records. Some activities are controlled in less detail than under ISO 3834-2.
ISO 3834-4:2021
Defines elementary quality requirements for welding activities with lower complexity and more limited control needs. It is appropriate only where permitted by the applicable product standard, contractual requirements and technical risks; the organization must still demonstrate its ability to meet specified requirements and use suitably qualified welding personnel.
ISO 3834-2, ISO 3834-3 or ISO 3834-4 should not be selected solely according to the size of the organization. A small manufacturer may still require ISO 3834-2 when producing safety-critical or complex products. The applicable level should be determined from the product standard, contract, material characteristics, welding processes, manufacturing conditions and consequences of welding imperfections.
How are the three levels of quality requirements selected?
ISO 3834-2 – Comprehensive
Generally suited to structures or equipment with demanding safety, reliability and traceability requirements; complex materials or joints; multiple welding processes; and stringent NDT, heat-treatment and technical-record requirements.
ISO 3834-3 – Standard
Generally suited to products with moderate complexity and quality requirements, using controlled welding technology while still requiring clearly defined documentation, personnel, procedures, inspection and records.
ISO 3834-4 – Elementary
Generally suited to simpler welded products, established materials and processes, limited technical requirements and lower consequences of welding imperfections, provided that no product standard or contract requires a higher level.
The final quality-requirement level is confirmed during application review. GIC Vietnam reviews the products, applicable standards, locations, welding processes according to ISO 4063, material groups according to ISO 15608:2025, thickness and diameter ranges, degree of mechanization, personnel and subcontracted activities before agreeing the assessment scope.
Key technical capabilities and controls
Confirm contractual requirements, product standards, manufacturing capability, acceptance criteria, materials, joint design, accessibility for welding and inspection, NDT, heat treatment and required deliverables.
Provide competent welding coordination personnel with clearly defined tasks, responsibilities and authority in accordance with ISO 14731 where required by the applicable level, and ensure that welders and welding operators are qualified for the work performed.
Make appropriate welding procedure specifications available at the workplace and qualify welding procedures before production in accordance with referenced standards or accepted technically equivalent documents.
Control the purchasing, identification, storage and issue of parent materials, electrodes, welding wires, shielding gases and fluxes to prevent mix-ups, damage, contamination or use under incorrect conditions.
Ensure that production, positioning, heating, heat-treatment, measuring and testing equipment is suitable, and perform maintenance, calibration or validation to the extent necessary.
Conduct required inspection before, during and after welding; use competent NDT personnel; and control inspection status, nonconformities, repairs, identification, traceability and records that demonstrate quality.
The ISO 3834 certification scope has to be specifically defined
Certification does not provide unlimited confirmation of all welding activities performed by an organization. The assessed scope is normally linked to:
- The applicable ISO 3834-2, ISO 3834-3 or ISO 3834-4 standard.
- Welded products, structures and services, together with relevant product standards.
- Workshop fabrication sites, field installation sites or customers' premises.
- Welding processes and process reference numbers according to ISO 4063, including the degree of mechanization where relevant.
- Material groups according to ISO 15608:2025 and the applicable thickness and diameter ranges.
- Supporting standards or documents used to demonstrate conformity in accordance with ISO 3834-5.
Benefits of implementing and obtaining ISO 3834 certification
Shift the focus from final detection of imperfections to prevention through planned control of procedures, personnel, equipment, materials and inspection.
Control of inputs and production conditions helps reduce errors, repair welding, wasted materials and the costs of nonconforming products.
Third-party certification provides independent evidence of the capability to control welding activities within the certified scope of products, materials, processes and locations.
Provide a foundation for meeting welding quality requirements referenced in tenders, contracts, manufacturing standards or international customer requirements.
Clarify the tasks, responsibilities and authority of welding coordination personnel, welders, welding operators, inspection and NDT personnel, and other relevant functions.
ISO 3834 controls can be integrated with ISO 9001, factory production control systems and sector- or product-specific quality management requirements.
ISO 3834 certification is suitable for:
- Manufacturers of steel structures, mechanical equipment, tanks, piping, pressure equipment, vehicles and other metallic products involving fusion welding.
- Contractors performing installation, repair or maintenance welding at construction sites or customers' premises.
- Manufacturers required to meet product standards, tender specifications, contracts or supplier-approval requirements.
- Organizations seeking to standardize and demonstrate their welding quality capability, whether or not they have implemented ISO 9001.
II. CERTIFICATION PROCESS
The assessment activities may be adjusted according to the selected ISO 3834 standard, products, applicable standards, locations and technical complexity. Overall, the ISO 3834 welding quality certification process is implemented in six steps:
The organization provides information in GF.22.01 and GF.22.02 on welded products and services, applicable standards, locations, welding processes, materials, dimensional ranges, personnel, equipment and subcontracted activities. GIC Vietnam reviews the application for completeness and determines the appropriate ISO 3834 standard, certification scope, assessment duration and required assessment-team competence.
GIC Vietnam prepares the assessment programme and plan, identifying the locations, welding processes and representative work to be witnessed. Key records reviewed may include the appointment and competence of welding coordination personnel, WPS and WPQR/PQR registers, welder and welding-operator qualifications, NDT personnel, equipment and welding quality control documents.
The assessment team evaluates implementation at the locations within scope, including requirements and technical reviews; interviews with welding coordination personnel; and controls for personnel competence, WPS and WPQR/PQR, materials, welding consumables, equipment, heating and PWHT, subcontracted activities, NDT and records. Where appropriate, welding activities are witnessed to verify compliance with the WPS and specified control conditions.
The results are documented in an assessment report describing conformity, nonconformities and the scope assessed. The organization analyses causes, implements corrective actions and submits evidence. Where necessary, GIC Vietnam performs additional on-site or documentary verification before the file proceeds to review.
The application file and assessment results are independently reviewed to confirm conformity with the applicable ISO 3834 standard and satisfactory resolution of nonconformities. When the requirements are met, GIC Vietnam makes the certification decision and issues a certificate with the approved technical scope and supporting standards or documents, as applicable.
During the certification cycle, GIC Vietnam conducts surveillance assessments according to the programme to confirm that welding capability and quality controls continue to be maintained. Changes to products, standards, locations, welding processes, materials, welding coordination personnel or subcontracted activities are reviewed, and a recertification assessment is conducted before the end of the cycle.
III. WHY CHOOSE GIC VIETNAM?
GIC operates in the field of conformity assessment through domestic and international networks and accreditation programmes. The specific competence and accredited scope depend on each certification programme. ISO 3834 assessments are organized according to the principles of independence and impartiality and are based on technical competence appropriate to the organization's welding technologies, materials, products and scope.
GIC Vietnam clearly defines the scope, plan and assessment activities from the application-review stage, focusing on processes, technical capabilities and evidence that directly affect welding quality. This approach helps organizations prepare effectively and make efficient use of time and resources throughout the certification process.
CONTACT INFORMATION
GIC VIETNAM
Hanoi: 12F, 14 Lang Ha Building, Giang Vo Ward
Telephone: 024 6275 2268 | Hotline: 0984 609 469
Email: tuandm@gicvn.vn
Ho Chi Minh City: R502, 160 Nam Ky Khoi Nghia
Telephone: 028 3930 7936
