Stainless Steel Coil Tube for Floating Roof Tank Heating Systems (Coiltube)
Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd is a precision-engineered heat exchange component specifically designed for self-made floating roof tank heating applications. This product represents a specialized class of coiled tubular structures fabricated from high-grade austenitic stainless steel, engineered to deliver efficient thermal transfer within petroleum storage tank heating systems. The coil tube integrates seamlessly with ring angle steel fixtures (annular angle steel jigs) to ensure structural integrity and optimal heat distribution across the tank's floating roof assembly.
This product embodies advanced metallurgical engineering principles, combining corrosion resistance, thermal conductivity, and mechanical durability to withstand the demanding operating conditions of oil and chemical storage facilities. The design draws upon extensive industry learning and practical application insights, particularly in the context of custom floating roof tank heating solutions.
Material & Properties
The coil tube is fabricated from premium austenitic stainless steel grades, selected for their exceptional combination of corrosion resistance, weldability, and thermal performance under aggressive chemical environments.
- Primary Material Grades: SUS304 (AISI 304), SUS316 (AISI 316), SUS316L (AISI 316L), and SUS321 (AISI 321) conforming to ASTM A213 and ASTM A312 standards.
- Corrosion Resistance: Superior resistance to pitting, crevice corrosion, and intergranular corrosion in acidic and chloride-rich environments typical of petroleum and chemical storage.
- Thermal Conductivity: Optimized thermal transfer characteristics ensuring efficient heat exchange between the heating medium and stored product.
- Mechanical Strength: High tensile strength and yield strength ensuring structural integrity under thermal cycling and pressure loading conditions.
- Temperature Range: Operable from cryogenic temperatures (−196°C / −321°F) up to 870°C (1,598°F) depending on grade selection.
- Surface Finish: Available in 2B, BA (Bright Annealed), and No.4 matte finishes for varying aesthetic and functional requirements.
Technical Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Product Category | Stainless Steel Coil Tube / Coiltube | ASTM A312 / ASTM A213 |
| Material Grades | SUS304, SUS316, SUS316L, SUS321 | ASTM A240 / EN 10088 |
| Outer Diameter (OD) | 6.35 mm – 323.85 mm (¼" – 12") | ASTM A511 / ASME B36.19M |
| Wall Thickness | 0.5 mm – 12.7 mm (0.020" – 0.500") | ASTM A312 |
| Coil Length | Custom, typically 50 m – 500 m per coil | Manufacturer Specification |
| Coil Diameter | Custom, typically 1,500 mm – 3,000 mm | Manufacturer Specification |
| Manufacturing Method | Cold-drawn seamless / Welded (TPAW/ERW) | ASTM A213 / EN 10216-5 |
| End Condition | Plain end / Beveled end / Threaded | ASME B1.20.1 |
| Fixture Type | Ring Angle Steel Jig (Annular Angle Steel Fixture) | Custom Engineering Design |
| Surface Treatment | Pickling & Passivation | ASTM A967 / ASTM A380 |
| Pressure Rating | Up to 16 MPa (2,320 psi) depending on dimensions | ASME BPV Code Section VIII |
| Heat Treatment | Solution Annealed (1050°C – 1150°C, water/quench cooled) | ASTM A312 |
Manufacturing Process
The production of the stainless steel coil tube for floating roof tank heating systems follows a rigorous multi-stage manufacturing protocol:
- Raw Material Selection: High-purity stainless steel wire rod or seamless tube blanks are sourced from certified mills, with incoming inspection verifying chemical composition (via spectroscopic analysis) and mechanical properties.
- Tube Forming: Seamless tubes are produced via the Pierceless Plug (PLT) or Mannesmann piercing process, or welded tubes are manufactured through Transverse Plasma Arc Welding (TPAW) or Electric Resistance Welding (ERW) methods, followed by cold drawing to achieve precise dimensional tolerances.
- Cold Drawing & Sizing: Tubes undergo multiple passes through calibrated drawing dies to achieve the specified outer diameter and wall thickness within tight tolerances (±0.05 mm OD tolerance).
- Solution Annealing: The drawn tubes are heat-treated in a protective atmosphere furnace (1050°C – 1150°C) followed by rapid quenching to restore full austenitic microstructure and eliminate cold-work stresses.
- Pickling & Passivation: Chemical treatment using mixed acid solutions removes mill scale and surface contaminants, followed by passivation to form a protective chromium oxide layer.
- Coil Winding: The finished tubing is wound into coils of specified diameter using precision winding machinery to prevent deformation, kinking, or surface damage.
- Ring Angle Steel Fixture Fabrication: Annular angle steel jigs are custom-fabricated using structural angle steel (typically Q235 or 304 stainless steel) to provide mounting and support structures for the coil tube within the floating roof tank assembly. These fixtures ensure proper spacing, thermal expansion accommodation, and secure anchoring.
- Assembly & Integration: The coil tube is installed within the ring angle steel fixture framework, forming the complete heating element assembly for the floating roof tank.
- Final Inspection & Testing: Each coil tube undergoes hydrostatic pressure testing (1.5× working pressure), dimensional verification, visual surface inspection, and non-destructive testing (NDT) as required.
Applications
The stainless steel coil tube for floating roof tank heating systems serves critical roles in the following industrial sectors:
- Petroleum Storage & Distribution: Heating of crude oil, heavy fuel oil, and viscous petroleum products stored in floating roof tanks to maintain flowability and reduce viscosity during transfer operations.
- Chemical Processing: Thermal management of aggressive chemical media in storage tanks, including acids, alkalis, and organic solvents requiring corrosion-resistant heating elements.
- Pharmaceutical Industry: Sanitary-grade heating applications where product purity and surface cleanliness are paramount.
- Food & Beverage Processing: Heating of edible oils, fats, and other viscous food products requiring hygienic stainless steel contact surfaces.
- Marine & Offshore: Fuel heating systems for marine vessels and offshore platforms where resistance to chloride-induced corrosion is essential.
- Waste Treatment & Environmental: Heating of sludge and waste materials in processing tanks requiring durable, corrosion-resistant heat exchange elements.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system ensuring full traceability and compliance with international standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- ISO 45001:2018 — Occupational Health & Safety Management System
- EN 10204 3.1 — Full Material Traceability Documentation
- ASTM International — Conformance to ASTM A213, A312, A240, A967 standards
- ASME Certification — Manufacturing under ASME "S" Stamp (where applicable)
- NACE MR0175 / ISO 15156 — Compliance for sour service applications
- Mill Test Reports (MTR) — Full chemical and mechanical property documentation per heat number
- Third-Party Inspection — Available from SGS, Bureau Veritas, or TUV upon request
Unique Selling Points
- Custom Engineering for Floating Roof Tanks: Proprietary design integrating coil tube heating elements with ring angle steel fixtures, specifically optimized for the unique thermal and structural demands of floating roof tank configurations.
- Superior Corrosion Performance: Utilization of SUS316L grade with low carbon content eliminates sensitization risk, providing unmatched resistance in chloride-containing environments common in petroleum storage.
- Thermal Efficiency: Optimized coil geometry maximizes heat transfer surface area while minimizing thermal losses, reducing energy consumption by up to 20% compared to conventional heating elements.
- Structural Durability: The combination of cold-drawn stainless steel tubing with engineered angle steel support fixtures ensures long-term reliability under cyclic thermal loading and mechanical vibration.
- Full Customization: Complete dimensional customization including coil diameter, tube OD, wall thickness, and coil length to match specific tank geometries and heating requirements.
- Industry Expertise: Leveraging accumulated practical experience in floating roof tank heating system design and implementation, ensuring solutions that address real-world operational challenges.
- Extended Service Life: Expected operational lifespan exceeding 15 years with minimal maintenance, providing superior total cost of ownership.
Note: All specifications are subject to final confirmation based on specific project requirements. Wenzhou Jixing Metal Materials Co., Ltd provides engineering consultation, custom design services, and post-sale technical support for all coil tube heating system installations.