Special Equipment Manufacturing License (TS) for Pressure Vessels and Pressure Piping Components — Clad and Composite Material Fabrication
1. Definition and Regulatory Framework
The Special Equipment Manufacturing License, designated as the "TS" license in China's regulatory system, is a mandatory national qualification issued by the State Administration for Market Regulation (SAMR) and its delegated provincial-level market supervision bureaus. Under the Special Equipment Safety Law of the People's Republic of China and the Regulations on the Safety Supervision of Special Equipment, any entity manufacturing pressure vessels, pressure piping components, or pressure-containing equipment that falls within the defined classification must hold a valid TS manufacturing license before commencing production.
For companies operating in the bimetallic cladding and weld overlay sector, this license is not merely a regulatory checkbox — it is the legal gateway to manufacturing composite-plate pressure vessels, clad-lined piping components, and overlay-reinforced pressure equipment. The license explicitly enumerates the permitted material grades, process methods, thickness ranges, and product categories that the licensee is authorized to produce. Without the TS license, no pressure equipment incorporating clad or overlay materials can be legally fabricated, inspected, or delivered into service.
2. Category Classification and Business Positioning
The TS license system operates on a tiered classification structure governed by the Special Equipment Safety Technology Supervision Regulations — Pressure Vessels (TSG 21-2016) and the Special Equipment Safety Technology Supervision Regulations — Pressure Piping Components (TSG 31-2018). These regulations define product categories, design parameters, and manufacturing scope boundaries.
2.1 Product Category Classification
| Category | Description | Typical Clad/Overlay Products |
|---|---|---|
| Class I (Class A) | High-pressure vessels, critical parameters | Composite-plate high-pressure reactors, clad-lined heat exchangers |
| Class II (Class B) | Medium-pressure vessels, moderate parameters | Clad-lined storage tanks, overlay-reinforced separators |
| Class III (Class C) | Low-pressure vessels, basic parameters | Clad-lined feed water heaters, overlay-lined transfer vessels |
| Pressure Piping Components | Flanges, fittings, valves, spools | Clad-lined pipe spools, overlay-reinforced flanges, composite fittings |
2.2 Process Scope Within the License
The TS license detail schedule explicitly lists the manufacturing processes authorized for the licensee. For a company specializing in clad and overlay technology, the critical process entries include:
- Weld Overlay / Cladding Welding: TIG (GTAW) and MIG (GMAW) weld overlay processes for corrosion-resistant linings and transition layers
- Explosion Cladding: Explosive welding and hydraulic explosive bonding for bonded clad plate production
- Composite Plate Fabrication: Post-bonding processing including flattening, cutting, forming, and welding of clad assemblies
- Heat Treatment: Post-weld heat treatment (PWHT) for overlay and clad structures
Each process entry in the license specifies permitted base material grades, cladding material grades, thickness ranges, and applicable product categories. Expanding the license scope requires separate application, technical demonstration, and regulatory review.
3. Technical Purpose and Strategic Value
3.1 Legal Authorization for Production
The primary function of the TS license is to establish legal authority to manufacture pressure equipment. For Cladding Technology Shanxi Co., Ltd., this means:
- Authorization to fabricate composite-plate pressure vessels meeting GB/T 150 series requirements
- Authorization to produce clad-lined pressure piping components under GB/T 20533 and related standards
- Legal basis for incorporating weld overlay and explosion-clad materials into pressure boundary components
- Eligibility to participate in tenders requiring certified pressure equipment manufacturers
3.2 Customer Confidence and Market Access
In the oil, gas, petrochemical, power generation, and chemical processing industries, the TS license serves as the fundamental credential demonstrating that a manufacturer has been evaluated by national authorities for:
- Technical capability in pressure equipment fabrication
- Adequate personnel qualifications (welders, NDT technicians, quality engineers)
- Sufficient equipment and facilities for the declared manufacturing scope
- Effective quality management system aligned with regulatory requirements
- Traceable process control and documented manufacturing procedures
3.3 Integration with International Standards
The TS license framework references and incorporates requirements from international standards including ASME BPVC Section VIII, ASTM specifications for clad materials, and ISO quality management standards. This creates a bridge between Chinese regulatory requirements and international engineering specifications, enabling domestically licensed manufacturers to serve both domestic and export markets.
4. Key Implementation Points and Licensing Process
4.1 Prerequisites for TS License Acquisition
| Requirement Category | Specific Criteria | Documentation Required |
|---|---|---|
| Quality Management System | QMS compliant with TSG 07-2019 | Quality manual, procedure documents, work instructions, records |
| Personnel | Qualified welders, NDT Level II/III, pressure vessel designers, quality inspectors | Certificates, training records, qualification scope |
| Equipment & Facilities | Welding equipment, NDT equipment, heat treatment furnaces, forming equipment, dimensional inspection tools | Equipment inventory, calibration certificates, capability verification |
| Manufacturing Procedures | WPS/PQR for all clad and overlay processes, forming procedures, inspection procedures | Approved WPS, qualified PQR, inspection plans |
| Sample Fabrication | Demonstration products manufactured to declared scope | Sample test reports, NDT results, dimensional verification |
4.2 Process Qualification for Clad and Overlay Methods
The TS licensing process requires demonstration of process capability through qualified procedures and test products. For each cladding or overlay technology route, the following must be established:
4.2.1 Weld Overlay (TIG/MIG) Process Qualification
- Welding Procedure Qualification Records (PQR): Demonstrating mechanical properties, microstructural integrity, and corrosion resistance of overlay deposits on specified base materials
- Welding Procedure Specifications (WPS): Documenting all essential and non-essential variables including heat input, travel speed, filler metal specifications, and post-weld requirements
- Welder Qualification: Each welder must be qualified on the specific overlay procedure, material combination, and position to be used in production
- Acceptance Criteria: Overlay thickness uniformity, absence of defects per NDT results, hardness profiles, and corrosion testing per applicable standards
4.2.2 Explosion Cladding Process Qualification
- Bonding Quality Verification: Shear testing, peeling testing, and macrograph examination of bond interfaces per ASTM A402 or GB/T 13817
- Plate Dimensional Control: Demonstration of flatness, thickness, and dimensional tolerances achievable after explosion welding and post-processing
- Material Compatibility Matrix: Documented qualified combinations of base and cladding materials with corresponding process parameters
- Post-Bonding Processing: Qualified procedures for flattening, cutting, machining, and forming of explosion-clad plates
4.2.3 Hydraulic Explosive Bonding Process Qualification
- Process Parameters: Water pressure levels, charge configurations, gap distances, and alignment tolerances
- Bond Integrity Testing: Equivalent bond quality verification to dry explosion welding, including interfacial strength and continuity
- Safety Documentation: Enhanced safety protocols specific to underwater explosive operations
- Product Scope Demonstration: Fabrication of demonstration plates and components within declared thickness and material ranges
4.3 Licensing Grade and Scope Management
The TS license operates on a graded system where the license grade determines the maximum design pressure, temperature, and product category the manufacturer can produce. Key considerations include:
| License Grade | Typical Pressure Range | Product Scope | Clad/Overlay Relevance |
|---|---|---|---|
| Level A | High-pressure (up to 100 MPa+) | Class A vessels, critical piping | High-specification clad-lined reactors, high-pressure overlay piping |
| Level B | Medium-pressure | Class B vessels, general piping | Standard clad-lined vessels, medium-pressure overlay components |
| Level C | Low-pressure | Class C vessels, basic piping | Low-pressure clad-lined tanks, general overlay work |
5. Applicable Standards and Acceptance Criteria
5.1 Primary Regulatory Standards
- TSG 21-2016: Special Equipment Safety Technology Supervision Regulations — Pressure Vessels
- TSG 31-2018: Special Equipment Safety Technology Supervision Regulations — Pressure Piping Components
- TSG 07-2019: Special Equipment Safety Technology Supervision Regulations — Manufacturing, Installation, Modification, and Repair Supervision
- TSG Z0004-2007: Special Equipment Manufacturing Unit Qualification Rules (superseded but historically relevant)
5.2 Material and Fabrication Standards
- GB/T 150.1–150.4: Pressure Vessels (design, materials, fabrication, inspection)
- GB/T 20533: Welded steel pressure vessels — Technical conditions
- GB/T 13817: Clad steel plates and sheets — Technical conditions
- GB/T 15243: Explosive welded clad plates — Technical conditions
- ASTM A402: Standard Specification for Explosive Welding of Metals
- ASTM A240: Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels
- ASME BPVC Section VIII Division 1: Rules for Construction of Pressure Vessels
- ASME BPVC Section IX: Qualification Rules for Welding, Brazing, and Fusing
5.3 Welding and Overlay Standards
- NB/T 47014: Qualification rules for welding procedure of pressure vessels
- NB/T 47015: Qualification rules for welders of pressure vessels
- NB/T 47013: Non-destructive testing of pressure vessels
- GB/T 985: Designation of welding methods
- GB/T 3323: Radiographic testing of welds
- GB/T 11345: Ultrasonic testing of welds
- GB/T 12606: Magnetic particle testing of welds
- GB/T 11358: Penetrant testing of welds
5.4 Inspection and Acceptance Criteria
| Inspection Type | Standard Reference | Acceptance Criteria for Clad/Overlay |
|---|---|---|
| Radiographic Testing (RT) | GB/T 3323, ASME V Article 2 | Acceptable per applicable vessel code; overlay zones inspected for porosity, lack of fusion |
| Ultrasonic Testing (UT) | GB/T 11345, ASME V Article 4 | Bond interface continuity verified; overlay thickness measured; no delamination |
| Magnetic Particle Testing (MT) | GB/T 12606, ASME V Article 7 | No linear indications in overlay welds; surface defects free |
| Penetrant Testing (PT) | GB/T 11358, ASME V Article 6 | No surface-breaking defects in overlay and clad surfaces |
| Hardness Testing | GB/T 231, ASTM E10 | Overlay hardness within specified range; no excessive hardness gradient at interface |
| Peel/Shear Testing | ASTM A402, GB/T 15243 | Bond strength exceeds minimum requirements for material combination |
| Corrosion Testing | GB/T 10125, ASTM B117 | Overlay demonstrates required corrosion resistance in service environment |
6. Common Risks and Controls
6.1 License Scope Creep and Non-Conformance
Risk: Manufacturing products outside the declared license scope, including unlisted material grades, thickness ranges, or process methods not covered by the TS license detail schedule.
Controls:
- Maintain a current, accessible license scope matrix cross-referenced against all active projects
- Implement project review gates at design, procurement, and fabrication stages to verify scope compliance
- Establish procedures for license scope expansion prior to accepting new product categories
- Train project managers and quality engineers on scope boundaries and escalation procedures
6.2 Process Qualification Gaps
Risk: Insufficient or outdated PQR/WPS coverage for clad and overlay processes, leading to non-conformance during regulatory audits or product inspection.
Controls:
- Maintain a comprehensive WPS/PQR database covering all active and anticipated material combinations
- Implement a qualification refresh cycle aligned with NB/T 47014 requirements
- Document all essential variable changes and requalify where required
- Conduct internal audits of procedure currency and welder qualification status quarterly
6.3 Personnel Qualification Expiration
Risk: Expired welder qualifications, NDT technician certifications, or designer approvals leading to invalid production records and potential license suspension.
Controls:
- Implement a personnel qualification tracking system with automated expiration alerts
- Maintain minimum qualified personnel levels at all times to meet TSG 07 requirements
- Schedule refresher training and requalification tests 60 days before expiration
- Document all personnel changes in the quality management system records
6.4 Regulatory Inspection Non-Conformances
Risk: Findings during periodic regulatory inspections (typically every 1–2 years) resulting in corrective actions, production suspension, or license downgrade.
Controls:
- Conduct internal mock audits annually using the TSG 07 inspection checklist
- Maintain complete traceability records for all pressure equipment manufactured
- Ensure all equipment calibration certificates are current and traceable to national standards
- Establish a non-conformance management system with documented corrective and preventive actions
- Engage with regulatory authorities proactively on process changes and scope expansions
7. Application Across the Three Technology Routes
7.1 TIG/MIG Weld Overlay Technology
The TS license is directly applicable to weld overlay operations performed on pressure vessels and piping components. Key license-relevant aspects include:
- Overlay on Pressure Boundary: When weld overlay is applied to the pressure-retaining surface of a vessel or piping component, it falls under the TS manufacturing scope and requires qualified procedures, qualified welders, and full NDT coverage
- Transition Layer Requirements: Multi-layer overlay sequences (e.g., 309L transition + 316L finish) must be fully documented in the WPS and qualified per NB/T 47014
- Post-Weld Heat Treatment: PWHT requirements for overlay on pressure vessels are governed by the applicable vessel code and must be documented in the manufacturing record
- Thickness Allowance: Overlay thickness is accounted for in the pressure design calculations per GB/T 150 or ASME VIII rules, requiring coordination between design and fabrication
License Contribution: The TS license authorizes Cladding Technology Shanxi to perform overlay work on pressure-retaining components, enabling direct value-add services to OEMs and EPC contractors who require certified overlay fabrication for corrosion protection of pressure equipment.
7.2 Hydraulic Explosive Bonding Technology
Hydraulic explosive bonding produces clad plates used as raw materials for pressure vessel and piping fabrication. The TS license relevance includes:
- Clad Plate Certification: Explosion-clad plates manufactured for pressure vessel applications must comply with GB/T 15243 or equivalent, with bond quality verified through standardized testing
- Downstream Fabrication Authorization: The TS license covers the fabrication of pressure vessels using these clad plates, including welding of the clad material, forming, and inspection
- Material Traceability: Each batch of hydraulic explosion-bonded plate must maintain full traceability from raw material through bonding to final product, as required by the TS quality system
- Forming and Welding Qualification: Post-bonding forming operations (rolling, bending, spinning) and welding operations on clad plates must be qualified within the TS scope
License Contribution: The TS license enables the company to supply certified clad plates and fabricated clad components to the pressure equipment industry, bridging the gap between raw bonded plate production and finished pressure equipment delivery.
7.3 Explosion Welding Technology
Explosion welding produces clad plates and components for pressure equipment service. TS license integration includes:
- Bond Quality Standards: Explosion weld bond quality must meet ASTM A402 or GB/T 15243 requirements, with testing methods and acceptance criteria documented in the manufacturing procedure
- Post-Explosion Processing: Flattening, machining, cutting, and forming of explosion-welded plates are manufacturing operations covered under the TS license when producing pressure equipment
- Interface Integrity in Service: The bond interface must maintain integrity under pressure vessel operating conditions including thermal cycling, mechanical stress, and corrosion exposure
- NDT of Bond Interface: Ultrasonic testing of the bond interface is required for pressure equipment applications, with acceptance criteria per NB/T 47013
License Contribution: The TS license authorizes the company to manufacture pressure vessels and piping components using explosion-welded clad materials, enabling integrated supply chains from clad plate production through final pressure equipment delivery under a single certified entity.
8. Strategic Recommendations for Qualification Building
8.1 License Scope Optimization
- Map current license scope against the company's product portfolio and identify gaps in material grades, thickness ranges, or product categories
- Prioritize scope expansions that address the highest-volume customer requirements
- Ensure all three technology routes (TIG/MIG overlay, hydraulic explosive bonding, explosion welding) are explicitly listed in the license process schedule
- Align scope expansion applications with major project pipelines to ensure timely qualification
8.2 Quality System Enhancement
- Implement a dedicated pressure equipment quality management system module within the existing QMS, specifically addressing clad and overlay operations
- Develop a master WPS/PQR database with full traceability to material certifications, welder qualifications, and NDT results
- Establish a regulatory compliance dashboard tracking license status, personnel qualifications, equipment calibration, and audit findings
- Conduct annual internal audits using the TSG 07-2019 inspection framework
8.3 Customer Value Proposition
- Leverage the TS license as a primary differentiator in tenders requiring certified pressure equipment manufacturers
- Offer integrated solutions combining clad plate production with pressure equipment fabrication under a single TS license
- Provide customers with complete traceability from raw materials through clad production to final pressure equipment inspection and certification
- Facilitate international project participation by demonstrating alignment between TS requirements and ASME/ISO standards
9. Conclusion
The Special Equipment Manufacturing License (TS) for pressure vessels and pressure piping components represents the foundational regulatory qualification enabling Cladding Technology Shanxi Co., Ltd. to legally manufacture and deliver clad and overlay pressure equipment across China's industrial sectors. This license is not a static credential but a living qualification that requires continuous investment in personnel training, equipment maintenance, process qualification, and quality system performance.
For a company operating across TIG/MIG weld overlay, hydraulic explosive bonding, and explosion welding technology routes, the TS license serves as the unifying regulatory framework that validates manufacturing capability, ensures product safety, and provides the legal basis for commercial delivery. Strategic management of license scope, proactive regulatory engagement, and continuous quality system improvement are essential to maintaining and expanding this critical qualification in a competitive market.