Stainless Steel Coil Tube — Dense Phase Section Sparging Air Application

Product Overview

The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd is a precision-engineered continuous-length tubing product specifically designed for high-performance industrial applications, with a proven track record in Dense Phase Section Sparging Air Systems (密相段松动风系统). Coil tubes offer distinct advantages over straight-length pipe in terms of flexibility, installation efficiency, and thermal expansion accommodation. This product line has been the subject of extensive engineering study and improvement, particularly regarding the enhancement of sparging air distribution uniformity and long-term operational reliability in dense-phase conveying and fluidized bed environments.

Coil tubing is supplied in continuous helical form, eliminating the need for field welding of individual pipe segments. This inherent design feature significantly reduces leak points, minimizes installation labor, and enhances system integrity — critical factors in high-temperature, high-pressure, or corrosive service environments.

Material & Properties

Stainless steel coil tubes are available in a range of alloy grades to suit diverse operating conditions:

Key mechanical properties include high tensile strength (typically 515–720 MPa depending on grade and condition), elongation of 30–40% (indicating good ductility and formability), and excellent fatigue resistance under cyclic thermal loading. The austenitic microstructure provides outstanding weldability and resistance to intergranular corrosion when properly stabilized or carbon-controlled (L grades).

Specifications

Parameter Specification
Outer Diameter (OD) 6.0 mm – 219.0 mm (custom sizes available)
Wall Thickness (WT) 0.5 mm – 12.0 mm
Coil Length Up to 1,500 m per coil (continuous, no joints)
Coil Diameter 1.0 m – 3.5 m (adjustable based on OD and WT)
Manufacturing Standard ASTM A213 / A269, ASME SA-213 / SA-269, EN 10216-5
Available Grades 304, 304L, 316, 316L, 310S, 321, 347, 2205, 904L
Surface Finish Pickled & Passivated (P&P), Brushed, Polished (2B, BA, No.4)
Maximum Operating Temperature Up to 1150°C (grade-dependent)
Maximum Operating Pressure Up to 32 MPa (design dependent)
Tolerance on OD ±0.05 mm to ±0.5 mm (per applicable standard)
Tolerance on Wall Thickness ±10% of nominal (or tighter upon request)

Manufacturing Process

The production of stainless steel coil tubing involves a rigorous multi-stage manufacturing sequence designed to ensure dimensional accuracy, metallurgical integrity, and surface quality:

  1. Hot Rolling: Stainless steel slabs are hot-rolled into seamless pipe blanks or pipe bodies at elevated temperatures (typically 1100–1250°C), followed by controlled cooling to establish the desired grain structure.
  2. Piercing & Extrusion: For seamless tube production, hot billets are pierced to create hollow sections, which are subsequently extruded to achieve precise OD and wall thickness dimensions.
  3. Heat Treatment (Solution Annealing): Tubes are solution-annealed at 1010–1150°C followed by rapid quenching (air or water) to dissolve carbides and homogenize the austenitic microstructure, ensuring maximum corrosion resistance.
  4. Cold Drawing: Tubes are cold-drawn through precision dies to achieve tight dimensional tolerances, improved surface finish, and enhanced mechanical properties (work hardening).
  5. Pickling & Passivation: The pickling process removes oxide scale and surface contaminants using acid solutions (typically HNO₃/HF mixtures), followed by passivation to form a protective chromium oxide film (Cr₂O₃).
  6. Coiling: Finished tubes are wound into continuous coils using automated coiling equipment with controlled tension to prevent kinking, ovality, or deformation. Each coil is inspected, labeled, and packaged for shipment.

Applications

Dense Phase Section Sparging Air Systems (Primary Application)

Coil tubes are extensively employed in dense phase pneumatic conveying systems, where sparging air (松动风) is distributed through a network of tubes to fluidize and mobilize solid particulate materials (such as coal, ash, or chemical powders) within dense-phase legs and transfer lines. The continuous coil configuration offers the following critical advantages in this application:

Additional Applications

Quality Certifications & Testing

Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system ensuring product conformity to international standards:

In-Process and Final Inspection

Unique Selling Points