Stainless Steel Coil Tube — Heat Batch Number Traceability Management System

1. Product Overview

The Stainless Steel Coil Tube (Product No. 211) manufactured by Wenzhou Jixing Metal Materials Co., Ltd is a precision-engineered cold-rolled or seamless stainless steel tube supplied in coiled form for downstream forming, bending, and fabrication processes. This product is governed by a rigorous Heat Batch Number Traceability Management System (Heat Lot Traceability), which ensures that every individual coil is permanently identified with a unique heat batch number that corresponds one-to-one with its associated Mill Test Certificate (MTC).

This traceability framework addresses a critical risk in industrial procurement — batch material mixing (Batch Cross-Contamination) — which can result in inconsistent mechanical properties, chemical composition deviations, and non-conformance to specified standards. By implementing strict heat lot identification and documentation protocols, Wenzhou Jixing Metal Materials Co., Ltd provides full supply-chain accountability from raw material smelting through final delivery.

2. Material & Properties

Stainless steel coil tubes are available in a wide range of austenitic, ferritic, and duplex alloy grades, each selected to meet specific corrosion resistance, mechanical strength, and temperature tolerance requirements:

• 304 / 304L (UNS S30400 / S30403) — General-purpose austenitic grade with excellent formability and corrosion resistance; widely used in food processing, chemical, and architectural applications.
• 316 / 316L (UNS S31600 / S31603) — Enhanced molybdenum content provides superior resistance to pitting and crevice corrosion in chloride-rich environments.
• 321 (UNS S32100) — Titanium-stabilized austenitic grade resistant to intergranular corrosion at elevated temperatures.
• 310S (UNS S31008) — High-temperature austenitic grade suitable for furnace components and heat-treatment equipment.
• 430 (UNS S43000) — Ferritic stainless steel with good oxidation resistance and magnetic properties.
• 2205 Duplex (UNS S32205) — High-strength duplex alloy combining austenitic and ferritic microstructures for demanding structural and corrosion applications.

Each grade is verified through spectroscopic analysis and mechanical testing, with results documented in the corresponding MTC and linked to the heat batch number stamped on the coil identification tag.

3. Specifications

Parameter	Specification / Range	Standard Reference
Product Form	Stainless Steel Coil Tube (盘管)	—
Product Number	211	Internal Catalog
Outer Diameter (OD)	6.00 mm – 159.00 mm	ASTM A554 / A269
Wall Thickness (WT)	0.30 mm – 6.00 mm	ASTM A554 / A269
Coil Inner Diameter (ID)	100 mm – 250 mm	Custom / Standard
Coil Length per Spool	Up to 1,500 m (continuous)	—
Available Grades	304, 304L, 316, 316L, 321, 310S, 430, 2205 Duplex	AISI / UNS
Surface Finish	No. 1 (Annealed & Pickled), 2B, BA (Bright Annealed), No. 4 Brushed	ASTM A480
Tolerance — OD	±0.10 mm (standard); ±0.05 mm (precision)	ASTM A554
Tolerance — Wall Thickness	±10% (standard); ±5% (precision)	ASTM A554
Heat Batch Identification	Permanent laser-engraved or stamped tag on each coil	ISO 9001 / EN 10204
MTC Correspondence	One-to-one mapping: Heat Batch Number ↔ MTC Document	EN 10204 Type 3.1
Applicable Standards	ASTM A554, ASTM A269, EN 10217-7, GB/T 12771, JIS G3459	International

4. Manufacturing Process

4.1 Raw Material Smelting & Casting

Stainless steel billets are produced via Argon Oxygen Decarburization (AOD) or Vacuum Arc Remelting (VAR) processes, ensuring precise control of carbon, sulfur, and trace element content. Each heat is assigned a unique Heat Batch Number at the point of smelting, initiating the traceability chain.

4.2 Hot Rolling & Annealing

Billets are hot-rolled into seamless pipe blanks and subsequently annealed to relieve internal stresses and achieve the required microstructure. Chemical composition is verified at this stage through optical emission spectrometry (OES) and the results are recorded against the heat batch number.

4.3 Cold Drawing / Cold Rolling

The seamless blanks undergo cold drawing or cold rolling to achieve the final tube dimensions with tight tolerances. This process enhances mechanical properties — particularly yield strength and surface finish quality — while maintaining dimensional accuracy.

4.4 Pickling & Passivation

Tubes are chemically pickled using mixed acid solutions (HNO₃ + H₂SO₄) to remove scale and impurities, followed by passivation to form a protective chromium oxide film. This step ensures optimal corrosion resistance and surface cleanliness.

4.5 Coiling & Identification

The finished tube is wound onto a coil spool. At this critical stage, the Heat Batch Number is permanently affixed to the coil via laser engraving or embossed metal tag. The identification includes:

• Heat Batch Number (smelting lot reference)
• Material Grade (e.g., 304L, 316L)
• Dimensions (OD × WT)
• Manufacturer Identification
• Production Date
• Coil Weight

4.6 Final Inspection & MTC Issuance

Each coil undergoes final dimensional inspection, surface quality assessment, and mechanical testing (tensile strength, hardness, impact testing as applicable). A Mill Test Certificate (MTC) conforming to EN 10204 Type 3.1 is issued, containing the heat batch number, full chemical analysis, mechanical test results, and applicable standard compliance declaration. The MTC is filed in the traceability database and made available to the purchaser upon request.

5. Heat Batch Traceability Management — Risk Prevention Framework

5.1 Purpose and Scope

The Heat Batch Number Traceability Management System is designed to eliminate the risk of Batch Material Mixing (批次混料), a procurement risk category where tubes from different smelting heats — potentially with different chemical compositions, mechanical properties, or heat treatment histories — are inadvertently combined during storage, transportation, or delivery. Such mixing can lead to:

• Inconsistent corrosion resistance across a production run
• Non-uniform mechanical properties causing structural failures
• Inability to perform effective root-cause analysis in the event of quality incidents
• Non-compliance with regulatory requirements in pharmaceutical, food, and aerospace sectors

5.2 Traceability Protocol

1. Unique Identification: Every coil receives a unique heat batch number at the smelting stage. This number propagates through all subsequent manufacturing and distribution stages without modification.
2. One-to-One MTC Mapping: Each heat batch number is linked to exactly one MTC document. The MTC contains complete metallurgical data and is stored in a secure, searchable database.
3. Segregation Controls: Coils from different heat batches are physically segregated during warehousing and clearly labeled to prevent cross-contamination.
4. Documented Chain of Custody: From factory gate to end-user delivery, each coil's heat batch number is recorded in shipping documents, packing lists, and delivery notes.
5. Periodic Audit: Internal quality audits verify that heat batch numbers on physical coils match database records and MTC documentation at defined intervals.

5.3 Digital Traceability Infrastructure

Wenzhou Jixing Metal Materials Co., Ltd maintains a Product Traceability Information System (PTIS) that enables end-users to query any heat batch number and retrieve the complete manufacturing history, including:

• Chemical composition (C, Si, Mn, P, S, Cr, Ni, Mo, Ti, etc.)
• Mechanical test results (tensile strength, yield strength, elongation, hardness)
• Heat treatment records (annealing temperature, duration, cooling method)
• Dimensional inspection data
• Surface finish verification
• Third-party inspection reports (where applicable)

6. Applications

Stainless steel coil tubes with verified heat batch traceability are employed across industries where material integrity and regulatory compliance are paramount:

• Pharmaceutical & Biotechnology: Clean-in-place (CIP) piping systems, sanitary process lines, and hygienic equipment where full material traceability is mandated by Good Manufacturing Practice (GMP) regulations.
• Food & Beverage Processing: Brewing, dairy, and beverage production lines requiring corrosion-resistant, easily cleanable tubing with documented material provenance.
• Chemical & Petrochemical: Reactor piping, heat exchangers, and process equipment handling aggressive media, where batch-specific material properties are critical to safety.
• Aerospace & Defense: Hydraulic lines, fuel systems, and structural tubing where traceability is required per AS9100 and NADCAP standards.
• Medical Devices: Endoscopes, surgical instruments, and implant fabrication where material certification is essential for ISO 13485 compliance.
• Automotive: Exhaust systems, fuel lines, and structural tubing where consistent material properties are required across production volumes.
• Oil & Gas: Subsea piping, wellhead components, and offshore platforms where corrosion resistance and traceability are critical for long-term reliability.
• Power Generation: Boiler tubes, heat exchanger elements, and nuclear-grade applications requiring full material pedigree documentation.

7. Quality Certifications & Compliance

Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management framework ensuring that all stainless steel coil tube products meet international standards:

• ISO 9001:2015 — Quality Management Systems certification covering design, manufacturing, and delivery processes.
• ISO 14001:2015 — Environmental Management Systems certification for sustainable manufacturing practices.
• EN 10204 Type 3.1 — Material Test Certificate (MTC) issuance per European standard, providing detailed inspection and test reports.
• ASME Stamp — American Society of Mechanical Engineers certification for pressure-containing equipment components (where applicable).
• NACE MR0175 / ISO 15156 — Compliance for sour service applications requiring resistance to sulfide stress cracking.
• NSF / ANSI 61 — Drinking water system certification for food-grade applications (where applicable).
• EU PED 2014/68/EU — Pressure Equipment Directive compliance for tubes used in pressure-containing systems.

8. Unique Selling Points

• End-to-End Heat Batch Traceability: Complete digital traceability from smelting heat through final delivery, with one-to-one MTC correspondence — providing absolute material provenance assurance.
• Batch Mixing Prevention: Dedicated segregation protocols, physical identification tags, and database cross-referencing eliminate the risk of batch cross-contamination.
• Regulatory-Grade Documentation: MTC documents conforming to EN 10204 Type 3.1 provide the level of detail required by pharmaceutical, aerospace, and nuclear regulatory authorities.
• Multi-Grade Capability: Availability across 304, 316, 321, 310S, 430, and 2205 Duplex grades in coil form enables single-source procurement with consistent quality control.
• Coil Form Efficiency: Continuous coil supply eliminates butt-weld joints, reducing leak points and improving production throughput for downstream fabricators.
• Custom Dimensional Precision: Tight tolerances on OD and wall thickness support precision forming, bending, and welding operations without secondary machining.

9. Ordering & Documentation

Upon order placement, purchasers receive:

1. A Packing List identifying each coil's heat batch number, grade, dimensions, and weight.
2. The corresponding Mill Test Certificate (MTC) for each heat batch, either in hard copy or as a secure digital PDF with cryptographic verification.
3. Access credentials to the Product Traceability Information System (PTIS) for online retrieval of full material documentation.
4. A Certificate of Conformity (COC) declaring compliance with the specified standard and grade.

Note: Wenzhou Jixing Metal Materials