Stainless Steel Coil Tube — Certified Solutions for Industrial Applications

Wenzhou Jixing Metal Materials Co., Ltd. is a leading manufacturer and supplier of high-performance stainless steel coil tubes, engineered to meet the most stringent international standards and regulatory requirements. Our coil tube products are designed for demanding applications across energy, petrochemical, marine, and process engineering sectors, delivering superior mechanical integrity, corrosion resistance, and dimensional precision in a continuous, coiled format that maximizes fabrication efficiency and material utilization.

Product Overview

Our stainless steel coil tubes are manufactured as continuous, wound configurations that offer significant advantages over cut-length pipe for high-volume fabrication and forming operations. These coil tubes are available in seamless and welded construction, with wall thicknesses and diameters tailored to specific application requirements. The coil format eliminates the need for field welding of individual lengths, reducing labor costs, minimizing leak points, and enabling rapid deployment in heat exchanger bundles, heat tracing systems, and process piping networks.

Wenzhou Jixing Metal Materials Co., Ltd. distinguishes itself through comprehensive certification readiness. Our coil tube products are available with full compliance documentation under PED (Pressure Equipment Directive 2014/68/EU), AD 2000 (German pressure vessel code), NACE (National Association of Corrosion Engineers), and major Class Society requirements (including DNV, ABS, LR, BV, CCS, and NK). This multi-certification capability positions our products as a single-source solution for global procurement programs that demand regulatory compliance across multiple jurisdictions.

Material & Properties

Available Grades

• Austenitic Grades: AISI 304 (1.4301), AISI 304L (1.4307), AISI 316 (1.4401), AISI 316L (1.4404), AISI 321 (1.4541), AISI 321H, AISI 347 (1.4550)
• Duplex Grades: 2205 (1.4462), 2507 (1.4410)
• Super Duplex Grades: UNS S32750, UNS S32760
• Specialty Alloys: Alloy 20 (1.4547), Alloy 6 (1.4529), Alloy 800H (1.4876)

Mechanical Properties (Typical — Grade 316L)

• Tensile Strength: ≥ 485 MPa (≥ 70 ksi)
• Yield Strength (0.2% offset): ≥ 205 MPa (≥ 30 ksi)
• Elongation: ≥ 40%
• Density: 8.0 g/cm³ (0.29 lb/in³)
• Thermal Conductivity (20°C): 16.3 W/(m·K) (0.94 BTU/hr·ft·°F)
• Modulus of Elasticity: 193 GPa (28 Msi)

Corrosion Resistance

Our austenitic and duplex stainless steel coil tubes exhibit excellent resistance to pitting, crevice corrosion, and intergranular attack. The 316L grade, with its molybdenum content of 2.0–2.5%, provides enhanced chloride resistance suitable for marine and chemical processing environments. Duplex grades deliver yield strengths approximately twice that of conventional austenitic grades while maintaining superior chloride stress corrosion cracking resistance.

Specifications

Parameter	Specification
Tube Outer Diameter	3.18 mm – 219.0 mm (1/8" – 8-5/8")
Wall Thickness	0.4 mm – 12.7 mm (0.016" – 0.5")
Coil Length (per coil)	20 m – 120 m (65 ft – 394 ft) — adjustable per order
Coil Inner Diameter	200 mm – 600 mm (7.9" – 23.6")
Construction	Seamless / Longitudinally Welded (ERW, TIG)
Surface Finish	Pickled & Passivated (PP), Bright Annealed (BA), No. 4 Brushed, Custom
End Condition	Plain, Beveled, Flanged, Threaded, or Custom Formed
Dimensional Tolerance	Per ASTM A213/A269, EN 10216-5, or customer-specific
Temperature Range	−196°C to +870°C (−320°F to +1600°F), grade-dependent
Pressure Rating	Up to 400 bar (5,800 psi) — per PED Category IV
Standard References	ASTM A213, A269, A778; EN 10216-5; JIS G3459

Manufacturing Process

Seamless Coil Tube Production

1. Slab Preparation: Cast slabs are reheated to forging temperature (1,150–1,250°C) and hot-rolled to reduce section dimensions.
2. Tube Blank Formation: The hot-rolled bar is pierced on a Mannesmann-type or plug-type piercing mill to create a hollow tube blank.
3. Hot Rolling / Elongation: The pierced blank is hot-rolled through a series of stands to achieve the target outer diameter and wall thickness with tight dimensional control.
4. Cold Drawing / Cold Rolling: Tubes requiring tight tolerances and superior surface finish undergo cold drawing or cold rolling, achieving dimensional accuracy within ±0.05 mm.
5. Solution Annealing: Tubes are austenitized at 1,050–1,150°C and rapidly quenched to restore full solution-strengthened microstructure and maximize corrosion resistance.
6. Pickling & Passivation: Acid pickling removes oxide scales; subsequent passivation treatment establishes a protective chromium oxide layer (≥ 100 ng/cm² Cr₂O₃).
7. Coiling: Finished tubes are wound onto precision-machined coil reels under controlled tension to prevent deformation or surface marking.

Welded Coil Tube Production

1. Strip Milling: Cold-rolled stainless steel strip is slit to precise width and annealed to achieve the required formability.
2. Forming & Welding: Strip is formed into a tube shape and longitudinally welded via ERW (Electrical Resistance Welding) or orbital TIG welding.
3. Weld Heat-Affected Zone Treatment: In-situ heat treatment or full solution annealing eliminates sensitization in the weld HAZ.
4. Non-Destructive Testing: 100% eddy current and hydrostatic testing verifies weld integrity and wall uniformity.
5. Finishing & Coiling: Surface finishing, dimensional verification, and controlled coiling complete the process.

Quality Certifications & Compliance

Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive certification portfolio that enables our stainless steel coil tubes to serve as qualified materials in pressure equipment, offshore structures, and critical process systems worldwide.

Pressure Equipment Directive (PED 2014/68/EU)

Our coil tube products are manufactured under PED-compliant quality systems, with full traceability from raw material mill certificates through final product release. We provide CE marking documentation, Manufacturer's Declarations of Incorporation, and Notified Body involvement for Category II–IV equipment. All material grades are verified against EN 10216-5 and EN 10217-7 specifications.

AD 2000 (German Pressure Vessel Code)

Certification under AD 2000-1 and AD 2000-2 ensures our coil tubes meet German statutory requirements for pressure vessels and piping systems. Documentation includes material certificates per EN 10204 3.1, weld procedure qualifications, and manufacturing surveillance records. Our AD 2000 certification is valid for materials specified in Part 2.3 (stainless steels).

NACE Compliance

Our coil tube products comply with NACE MR0175/ISO 15156 (Oil and Gas Equipment — Materials to Resist Sulfide Stress Cracking and Hydrogen Damage). Materials are supplied with HIC (Hydrogen-Induced Cracking) test reports, SM (Sulfide Stress) test results, and controlled interstitial carbon specifications for sour service applications.

Class Society Certification

Available with approval and material certification from major classification societies including:

• DNV (Det Norske Veritas) — Type Approval
• ABS (American Bureau of Shipping) — Material Approval
• LR (Lloyd's Register) — Class Approval
• BV (Bureau Veritas) — Class Approval
• CCS (China Classification Society) — Class Approval
• NK (Nippon Kaiji Kyokai) — Type Approval

Additional Certifications

• ISO 9001:2015 — Quality Management System
• ISO 3834-2 — Quality Requirements for Fusion Welding of Steel
• EN 1090-2 — Execution of Steel Structures (where applicable)
• NADCAP (National Aerospace and Defense Contractors Accreditation Program) — pending/available on request

Special Certification Surcharges

Important Notice: For projects requiring PED, AD 2000, NACE, or Class Society certification documentation, a special certification surcharge may apply. This surcharge covers the costs of Notified Body audits, witness testing, surveillance inspection, and certification documentation preparation. The certification fee structure is as follows:

• Standard Orders (≥ 5,000 kg): Certification costs are typically absorbed into the unit price with no separate surcharge.
• Small-Batch Orders (< 5,000 kg): A certification handling surcharge of 3–8% of order value may apply to cover proportional audit and documentation costs.
• First-Time Collaboration: An initial certification setup fee may be charged to cover the one-time cost of establishing traceability records, Notified Body registration, and initial witness testing for a new customer qualification.
• Multiple Certifications: When multiple certifications (e.g., PED + AD 2000 + Class Society) are required simultaneously, a consolidated surcharge is applied that is lower than the sum of individual certification fees.

Certification surcharges are transparently quoted during the RFQ stage and are itemized separately from material and manufacturing costs to ensure full cost transparency for procurement teams.

Applications

Energy & Power Generation

• Boiler tubes and superheater elements in thermal power plants
• Heat exchanger tubing for nuclear and fossil-fuel power generation
• Steam generator tubes for marine propulsion systems

Petrochemical & Oil & Gas

• Refinery process piping for crude distillation and FCC units
• Sour service heat exchangers (H₂S-containing environments)
• Offshore platform risers and subsea process lines
• Chemical reactor internals and catalyst support structures

Marine & Offshore

• Ballast water treatment system piping
• Scrubber and exhaust gas cleaning system components
• Marine heat exchangers and coolers
• Offshore platform structural and process tubing

Food & Pharmaceutical

• Hygienic process tubing for dairy, beverage, and pharmaceutical manufacturing
• CIP (Clean-in-Place) compatible heat exchangers
• Sterilization system tubing (SIP-ready)

Automotive & Aerospace

• Exhaust system heat shielding tubes
• Turbocharger waste heat recovery components
• Aircraft hydraulic and pneumatic tubing (qualified grades)

Unique Selling Points

• Multi-Certification Readiness: Industry-leading capability to supply PED, AD 2000, NACE, and Class Society certified coil tubes from a single source, reducing supplier qualification burden for global procurement teams.
• Continuous Coil Format: Eliminates field welding, reduces leak points, and enables automated U-bend forming and heat exchanger assembly — saving 30–50% in fabrication labor compared to cut-length alternatives.
• Full Traceability: Every coil is traceable to individual heat numbers with complete mill test certificates, chemical analysis, mechanical test results, and NDT records.
• Transparent Certification Pricing: Certification surcharges are clearly itemized and predictable, with volume-based absorption thresholds that reward larger order quantities.
• Custom Coil Configuration: Flexible coil lengths, diameters, and end conditions tailored to specific heat exchanger designs or process layouts, minimizing offcut waste.
• Global Delivery: Established logistics network with experience in export packaging, documentation, and compliance for shipments to EU, North American, Middle Eastern, and Asian markets.

Order & Compliance Guidance

When placing orders requiring special certification, customers should specify:

1. The applicable code(s) and edition (e.g., PED 2014/68/EU Cat. III, AD 2000-1 2020, NACE MR0175 Rev. 2020)
2. The relevant Class Society and approval number (if previously obtained)
3. Required test protocols (hydrostatic pressure, eddy current, TOFD, RT, etc.)
4. Documentation format requirements (EN 10204 3.1, 3.2, or customer-specific)
5. Whether certification surcharge absorption applies based on order quantity

Wenzhou Jixing Metal Materials Co., Ltd. provides dedicated technical support throughout the certification process, including coordination with Notified Bodies, scheduling of witness testing, and preparation of all required documentation packages. Our engineering team is available for pre-order consultations to ensure that material specifications, manufacturing controls, and certification requirements are aligned before production commences.