Seamless Stainless Steel Fluid Transport Coil Tube — GB/T 14976
Product Overview
The Seamless Stainless Steel Fluid Transport Coil Tube manufactured by Wenzhou Jixing Metal Materials Co., Ltd is a premium-grade coiled tubing solution engineered specifically for fluid conveying applications. Conforming to the rigorous GB/T 14976 national standard for seamless steel tubes for fluid transport, this product delivers exceptional pressure resistance, corrosion durability, and dimensional precision in a continuous coil configuration. Available in a range of stainless steel grades, this coil tube is designed to meet the demanding requirements of industrial fluid handling systems across chemical, pharmaceutical, food and beverage, energy, and general engineering sectors.
Material & Properties
The coil tubes are produced from high-quality austenitic and duplex stainless steel grades, offering superior resistance to pitting, crevice corrosion, and general chemical attack. Key material characteristics include:
- Corrosion Resistance: Excellent resistance to aqueous environments, acidic media, and oxidizing conditions
- Mechanical Strength: High yield strength and tensile strength ensuring reliable pressure containment under operating conditions
- Formability: Superior cold-forming and bending characteristics inherent to austenitic microstructures
- Weldability: Excellent weldability for on-site fabrication and system integration
- Hygienic Surface: Available in polished or electropolished finishes suitable for sanitary and food-grade applications
- Temperature Performance: Retains mechanical integrity across a wide operating temperature range from cryogenic to elevated temperatures
Specifications
| Parameter | Specification |
|---|---|
| Standard | GB/T 14976 — Seamless Steel Tubes for Fluid Transport (General Requirements) |
| Product Form | Coil Tube (Continuous Coil Configuration) |
| Manufacturing Method | Seamless (Hot Rolled / Cold Drawn) |
| Material Grades | SUS304, SUS304L, SUS316, SUS316L, SUS321, SUS310S, SUS316Ti, and other custom grades |
| Outer Diameter (OD) | 6 mm – 114 mm (custom sizes available upon request) |
| Wall Thickness | 0.5 mm – 6.0 mm |
| Surface Finish | 2B, No. 1, Polished (Ra ≤ 0.8 μm), Electropolished (Ra ≤ 0.4 μm) |
| Coil Length | Continuous lengths up to 500 m per coil (custom lengths available) |
| End Condition | Plain end, beveled end, or custom prepared ends |
| Tolerance | OD: ±0.1 mm; Wall Thickness: ±10% |
| Maximum Working Pressure | Up to 4.0 MPa (dependent on grade, OD, and wall thickness) |
Manufacturing Process
Each coil tube undergoes a meticulously controlled multi-stage manufacturing process to ensure compliance with GB/T 14976 and deliver consistent quality:
- Raw Material Selection: Only certified stainless steel billets from approved suppliers are used, with full chemical composition verification prior to processing.
- Piercing & Hot Rolling: Billets are heated to forging temperature and pierced to produce seamless hollow blanks, ensuring a weld-free tubular structure with superior pressure containment.
- Cold Drawing & Sizing: Tubes are cold-drawn through precision dies to achieve exact dimensional tolerances and improved surface finish.
- Coiling: Finished tubes are carefully coiled on large-diameter reels to prevent deformation, kinking, or surface damage.
- Heat Treatment (Annealing): Where required, tubes undergo solution annealing to relieve residual stresses and restore optimal mechanical properties.
- Surface Finishing: Final polishing or electropolishing is applied to achieve the specified surface roughness for the target application.
- Quality Inspection: Every coil undergoes comprehensive testing as detailed below.
Quality Certifications & Testing
Wenzhou Jixing Metal Materials Co., Ltd adheres to stringent quality assurance protocols aligned with the GB/T 14976 standard. All coil tube products are subjected to the following mandatory inspections:
- Hydrostatic Pressure Test: Every coil tube is 100% hydrostatically tested at a pressure exceeding the minimum specified pressure per GB/T 14976 to verify structural integrity and absence of leaks or wall defects.
- Non-Destructive Testing (NDT): Electromagnetic testing (ET) and ultrasonic testing (UT) are performed to detect internal and surface discontinuities, ensuring zero-defect delivery.
- Mechanical Property Verification: Tensile strength, yield strength, and elongation are tested on representative samples to confirm compliance with minimum mechanical requirements specified in GB/T 14976.
- Chemical Composition Analysis: Spectrometric analysis verifies alloy content within specified ranges for each grade.
- Dimensional Inspection: Outer diameter, wall thickness, and roundness are measured at defined intervals along the coil length.
- Certification Documentation: Each shipment is accompanied by a full mill test certificate (MTC) including EN 10204 3.1 certificate, chemical analysis report, and mechanical test results.
Applications
The Seamless Stainless Steel Fluid Transport Coil Tube is widely employed in the following industries and applications:
- Chemical Processing: Conveyance of corrosive liquids, acids, alkalis, and solvents in reactor loops, heat exchangers, and pipeline systems.
- Pharmaceutical & Biotech: Sanitary-grade fluid transfer, CIP/SIP systems, and process piping where hygienic standards are critical.
- Food & Beverage Industry: Milk, juice, beer, and other food product transfer systems requiring non-reactive, easy-to-clean tubing.
- Oil & Gas: Subsea umbilicals, flow lines, and corrosion-resistant piping in harsh offshore environments.
- Power Generation: Boiler feedwater lines, condensate return systems, and steam distribution in thermal and nuclear power plants.
- Medical Equipment: Tubing for medical gas delivery, dialysis machines, and surgical instrument manufacturing.
- General Engineering: Compressed air lines, hydraulic systems, and structural fluid transport in industrial facilities.
Unique Selling Points
- Full GB/T 14976 Compliance: Manufactured and tested to the complete requirements of China's national standard for seamless fluid tubes, ensuring regulatory acceptance in domestic and international markets.
- 100% Hydrostatic Testing: Every single coil is pressure-tested — no sampling — providing absolute assurance of leak-free, structurally sound product.
- Seamless Construction: The absence of a weld seam eliminates the primary failure point found in welded tubing, delivering superior pressure containment and fatigue resistance.
- Coil Configuration Advantage: Continuous coil delivery minimizes field joints, reduces installation time, and provides greater layout flexibility compared to straight-length pipe.
- Multi-Grade Availability: A comprehensive range of stainless steel grades accommodates diverse corrosion and temperature requirements from a single trusted supplier.
- Traceable Quality: Full material traceability from raw steel mill to finished coil, backed by comprehensive documentation for audit and compliance purposes.
Ordering & Customization
Wenzhou Jixing Metal Materials Co., Ltd offers standard sizes as well as fully customized coil tube solutions. Custom dimensions, special grades, specific surface finishes, and tailored coil lengths are available upon request. Technical consultation and sample provision are provided to assist customers in selecting the optimal product configuration for their specific fluid transport application.