Stainless Steel Coil Tube for Catalytic Regenerator Heat Extraction System

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 catalytic regenerator heat extraction systems in petrochemical refining operations. These coil tubes serve as critical heat transfer elements within Fluid Catalytic Cracking (FCC) units, where they extract thermal energy from high-temperature catalyst beds to generate high-pressure steam for power generation and process heating.

Based on extensive field experience and failure analysis studies conducted at major refineries such as the Shijiazhuang Refinery, these coil tubes are engineered to withstand extreme operating conditions including temperatures exceeding 700°C, high-velocity catalyst particle erosion, and aggressive chemical environments containing sulfur compounds, sodium salts, and metal chlorides. The product represents a synthesis of metallurgical expertise, thermal engineering principles, and process-specific design requirements to ensure long-term reliability in one of the most demanding applications in the petrochemical industry.

Material & Properties

The coil tubes are fabricated from high-temperature resistant stainless steel grades selected for their exceptional oxidation resistance, thermal stability, and mechanical strength at elevated service temperatures. Primary material grades include:

Key Mechanical Properties

Property TP310H TP347H Test Standard
Tensile Strength (≥ MPa) 520 550 ASTM A213
Yield Strength (≥ MPa) 205 205 ASTM A213
Elongation (%) 30 40 ASTM A213
Operating Temperature Range (°C) -200 to 1150 -196 to 980 —
Thermal Conductivity at 100°C (W/m·K) 25.7 15.3 —
Creep Strength at 800°C (MPa/1000h) 50 80 ASTM E139

Specifications

Parameter Specification Standard Reference
Tube Outer Diameter (OD) 25.4 mm – 50.8 mm (1" – 2") ASTM A213 / ASME B36.19M
Wall Thickness 3.0 mm – 6.35 mm (1/8" – 1/4") ASTM A213
Coil Mean Diameter 300 mm – 1500 mm (customizable) Project-specific
Coil Length per Section 15 m – 120 m (continuous coil) —
Surface Finish Mill finish or electropolished (Ra ≤ 0.4 μm) ASTM A967
End Preparation Plain end, beveled end, or threaded (per drawing) ASME B31.3
Design Pressure Up to 20 MPa (2900 psi) ASME BPV Code Section I
Design Temperature Up to 750°C (service) / 850°C (peak) ASME BPV Code Section I
Tolerance on OD ±0.05 mm ASTM A213
Tolerance on Wall Thickness ±10% of nominal ASTM A213
Maximum Straightness Deviation ≤ 1.5 mm/m —
Coil Roundness ±2% of mean diameter —

Manufacturing Process

The production of catalytic regenerator heat extraction coil tubes follows a rigorous multi-stage manufacturing process designed to ensure metallurgical integrity, dimensional accuracy, and long-term service reliability:

  1. Raw Material Selection & Inspection: Stainless steel seamless tube blanks are sourced from certified mills with full chemical and mechanical property documentation. Incoming material undergoes positive material identification (PMI) via X-Ray Fluorescence (XRF) spectroscopy and visual inspection for surface defects.
  2. Heat Treatment & Solution Annealing: Tubes are solution annealed at 1050-1150°C followed by controlled air or water quenching to achieve a fully austenitic microstructure with maximum corrosion and oxidation resistance. For TP347H, stabilization annealing is performed at 1050°C to precipitate niobium carbides and prevent chromium depletion at grain boundaries.
  3. Precision Coil Forming: The annealed tubes are formed into precise coils using CNC-controlled coil winding equipment. The forming process employs calibrated mandrels and tension-controlled feed systems to prevent cross-sectional deformation, maintain uniform wall thickness, and achieve the required coil geometry without inducing residual stresses.
  4. Post-Forming Stress Relief: Coiled assemblies undergo controlled stress relief annealing at 850-950°C to eliminate forming-induced residual stresses that could accelerate creep deformation or stress corrosion cracking during service.
  5. Non-Destructive Testing (NDT): Each coil section undergoes comprehensive NDT including:
    • Eddy Current Testing (ECT) per ASTM E309 for internal and external surface defect detection
    • Visual Inspection (VT) for surface condition and dimensional verification
    • Dimensional measurement at multiple points along the coil length
  6. End Preparation & Final Inspection: Tube ends are prepared per engineering drawings, and each coil receives a comprehensive final inspection report including material traceability documentation, dimensional verification records, and NDT results.

Applications

These stainless steel coil tubes are purpose-engineered for the following critical applications:

Quality Certifications & Compliance

Wenzhou Jixing Metal Materials Co., Ltd. maintains comprehensive quality management systems and certifications ensuring product conformity to international standards:

Unique Selling Points

Failure-Informed Design Philosophy: The product specifications and material selections are informed by real-world failure analysis data from major refinery operations. Studies such as the Shijiazhuang Refinery catalytic regenerator coil tube failure analysis have identified critical degradation mechanisms — including molten salt corrosion, thermal stress cracking, and catalyst erosion — that directly inform material selection, wall thickness optimization, and heat treatment protocols.