Stainless Steel Coil Tube for Industrial Heat Transfer Systems

Product Overview

The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered heat transfer component designed for demanding industrial applications, particularly in water jacket furnace systems and thermal oil circulation circuits. These coil tubes serve as critical conduits for transferring thermal energy between working fluids and process environments, operating under sustained high-temperature and high-pressure conditions.

This product line is developed with deep consideration of failure modes observed in field applications—specifically addressing the root causes of coil tube leakage in water jacket furnace systems, including thermal fatigue cracking, corrosion-assisted stress rupture, and manufacturing defects that compromise long-term integrity.

Material & Properties

Coil tubes are fabricated from high-grade austenitic stainless steel grades selected for superior resistance to thermal cycling, oxidation, and corrosion under aggressive industrial environments.

Specifications

Parameter Specification
Outer Diameter (OD) Φ6 mm – Φ50 mm (customizable)
Wall Thickness 0.5 mm – 3.0 mm
Coil Diameter 100 mm – 600 mm
Coil Length Up to 500 m per coil (continuous)
Surface Finish Bright annealed / Pickled & passivated (Ra ≤ 0.8 μm)
Dimensional Tolerance ±0.05 mm (OD); ±0.05 mm (wall thickness)
Maximum Operating Pressure Up to 2.5 MPa (design-dependent)
Maximum Operating Temperature Up to 870°C (grade-dependent)
Heat Transfer Fluid Thermal oil, water, steam, or specialty heat transfer media
Standard References ASTM A213, ASTM A269, GB/T 12771, GB/T 14976

Manufacturing Process

The production process is designed to eliminate the failure mechanisms identified in field failure analyses of water jacket furnace coil tube systems:

  1. Raw Material Selection & Inspection: Only certified ingots with verified chemical composition and traceability are used. Incoming materials undergo spectroscopic analysis (PMI) to confirm grade compliance.
  2. Precision Seamless Tube Forming: Tubes are produced via cold drawing or hot-rolling processes to ensure uniform wall thickness and absence of laminations or inclusions that could initiate fatigue cracks.
  3. Coil Winding & Forming: Computer-controlled coil winding machines ensure consistent bend radius (minimum bend radius ≥ 5× OD) to prevent localized stress concentration and thinning at coil joints.
  4. Solution Annealing: Tubes are annealed at 1050°C – 1150°C followed by rapid quenching to achieve full solution-treated microstructure, eliminating sensitization and restoring ductility.
  5. Pickling & Passivation: Surface treatment removes oxide scale and establishes a protective chromium oxide passive layer for enhanced corrosion resistance.
  6. Non-Destructive Testing (NDT): 100% eddy current testing (ECT) and ultrasonic testing (UT) to detect wall thickness variations, internal defects, and surface discontinuities.
  7. Hydrostatic Pressure Testing: Each coil is pressure-tested at 1.5× maximum design pressure for a minimum dwell time of 30 seconds to verify leak-tightness.
  8. Thermal Cycling Simulation: Selected batches undergo accelerated thermal cycling tests (simulating furnace operating conditions) to validate long-term fatigue resistance.

Applications

Quality Certifications & Compliance

Wenzhou Jixing Metal Materials Co., Ltd. maintains rigorous quality management systems ensuring full traceability and compliance with international standards:

Unique Selling Points

This product line distinguishes itself through a failure-informed design philosophy. Drawing directly from documented failure analyses of water jacket furnace coil tube leakage—wherein thermal fatigue, microstructural sensitization, and manufacturing inconsistencies were identified as primary root causes—the manufacturing process has been systematically enhanced to address each failure mode. The result is a coil tube product with demonstrably extended service life, reduced unplanned downtime, and superior reliability in continuous high-temperature thermal cycling applications.