Stainless Steel Coil Tube with Hydrostatic Pressure Testing — Wenzhou Jixing Metal Materials Co., Ltd.
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. manufactures high-grade stainless steel coil tubes engineered for demanding industrial applications requiring superior corrosion resistance, mechanical integrity, and long-term operational reliability. Each coil tube is subjected to a rigorous hydrostatic pressure test (静水保压) as a mandatory pre-shipment quality gate, ensuring that every product delivered to customers meets the highest standards of safety and performance.
The coil tube product line is designed for continuous forming, bending, and welding processes in heat exchangers, HVAC systems, chemical processing equipment, and food-grade manufacturing lines. The coiled configuration allows for efficient downstream processing with minimal material waste and reduced labor costs.
Material & Properties
- Material Grades: 304, 304L, 316, 316L, 321, 310S, and custom alloy specifications
- Corrosion Resistance: Excellent resistance to atmospheric, chemical, and intergranular corrosion; 316/316L grades offer superior chloride resistance
- Mechanical Properties: High tensile strength with excellent ductility, enabling reliable cold forming and bending without cracking
- Temperature Range: Suitable for cryogenic to high-temperature service (up to 870°C for 304/304L grades)
- Surface Finish: Bright annealed (BA), pickled, or polished to customer specification
- Hygienic Compliance: Available in sanitary-grade finish meeting FDA and 3-A standards
Specifications
| Parameter | Specification |
|---|---|
| Outer Diameter | 6.0 mm – 159.0 mm (0.24 in – 6.26 in) |
| Wall Thickness | 0.5 mm – 12.0 mm (0.020 in – 0.472 in) |
| Coil Length | Custom (typically 50 m – 300 m per coil) |
| Coil Diameter | 500 mm – 1500 mm (19.7 in – 59.1 in) |
| Manufacturing Method | Seamless (P/M) or Welded (ERW/Automatic Submerged Arc) |
| Standard References | ASTM A554, ASTM A778, ASTM A269, EN 10217, EN 10216, GB/T 14976 |
| Tolerance (OD) | ±0.10 mm to ±0.25 mm (per customer requirement) |
| Tolerance (Wall) | ±10% of nominal wall thickness |
| Hydrostatic Test Pressure | 1.5 × Design Pressure |
| Pressure Hold Time | ≥ 5 seconds with zero leakage |
| Packaging | Wooden crate / steel banding / export-grade packaging |
Manufacturing Process
- Raw Material Selection: Virgin stainless steel billets or hot-rolled coils sourced from certified mills with full traceability documentation.
- Forming: Seamless tubes produced via piercing and cold drawing; welded tubes formed through ERW or TIG welding processes with precise seam control.
- Heat Treatment: Solution annealing at 1010°C – 1150°C followed by controlled cooling to achieve uniform microstructure and optimal mechanical properties.
- Sizing & Coiling: Cold drawing or rolling to final dimensions, followed by precision coiling on calibrated reels to ensure consistent spring-back characteristics.
- Surface Treatment: Pickling, passivation, and/or polishing to achieve specified surface finish and corrosion protection.
- Dimensional Inspection: Ultrasonic testing (UT), dimensional gauging, and visual inspection at defined intervals.
- Hydrostatic Pressure Testing (Mandatory): Every coil tube batch undergoes hydrostatic pressure testing at 1.5 times the design pressure with a minimum hold time of 5 seconds. Zero leakage is the absolute pass criterion — any indication of seepage, weeping, or pressure drop results in immediate rejection.
- Final Inspection & Packaging: Material certification verification, batch traceability tagging, and protective packaging for export or domestic delivery.
Hydrostatic Pressure Testing — Critical Quality Gate
The hydrostatic pressure test (静水保压) is the definitive proof of tube integrity. At Wenzhou Jixing Metal Materials Co., Ltd., this test is not optional — it is a mandatory, non-negotiable pre-shipment requirement for every coil tube product.
Test Protocol
- Test Medium: Clean water with appropriate additives to prevent corrosion during testing
- Test Pressure: 1.5 × the specified design pressure of the tube
- Hold Duration: Minimum 5 seconds at full test pressure
- Pass Criteria: Zero leakage — no visible seepage, weeping, pressure drop, or surface moisture
- Failure Action: Immediate quarantine, root-cause analysis, and rejection of affected batch
- Documentation: Test records retained with full batch traceability for customer audit purposes
This rigorous testing protocol ensures that every coil tube delivered by Wenzhou Jixing Metal Materials Co., Ltd. is structurally sound, leak-free, and ready for safe integration into pressure-containing systems.
Applications
- Heat Exchangers & Boilers: Condensers, evaporators, reboilers, and cooling coils in petrochemical and power generation facilities
- HVAC Systems: Refrigeration coils, air conditioning heat exchangers, and chiller components
- Chemical Processing: Reactor internals, distillation columns, and process piping in aggressive chemical environments
- Food & Pharmaceutical: Hygienic process lines, CIP/SIP systems, and sanitary heat exchangers
- Oil & Gas: Subsea umbilicals, flow lines, and offshore platform tubing
- Automotive & Aerospace: Fuel lines, hydraulic systems, and exhaust components
- Energy & Power: Solar thermal collectors, geothermal systems, and nuclear-grade components
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System certification
- ISO 3834 — Welding quality requirements compliance
- ASME — Manufacturer's Stamp (where applicable)
- EN 10204 3.1 — Third-party inspection certification for material compliance
- API 5L / API 5CT — Oil and gas industry standards compliance
- NACE MR0175 / ISO 15156 — Sulfide stress cracking resistance (for sour service applications)
- NSF/ANSI 61 — Drinking water system compliance (for food-grade applications)
Unique Selling Points
- 100% Hydrostatic Test Coverage: Unlike many suppliers who perform sampling-based testing, Wenzhou Jixing Metal Materials Co., Ltd. tests every coil tube batch at 1.5× design pressure with ≥5-second hold time — zero compromise on safety.
- Full Traceability: Each coil tube is linked to mill certificates, heat numbers, and test records, enabling complete supply chain transparency.
- Custom Configuration: Flexible manufacturing capabilities accommodate custom dimensions, wall thicknesses, coil diameters, and surface finishes to match specific project requirements.
- Comprehensive Material Range: Availability of austenitic, duplex, and specialty alloy grades from a single source simplifies procurement and ensures consistency.
- Export-Grade Quality: Products meet international standards (ASTM, EN, ASME) and are shipped worldwide with full documentation packages.
- Proven Reliability: Established manufacturing expertise with a track record of delivering leak-free, pressure-tested tubing to critical infrastructure projects globally.