Stainless Steel Coil Tube (Coiltube) — Product Technical Specification

Product Overview

The Stainless Steel Coil Tube (hereinafter referred to as "Coiltube") is a precision-engineered tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is designed as a continuously wound, helical or spiral configuration of seamless stainless steel tubing, optimized for heat exchange, fluid transfer, and process engineering applications. The Coiltube eliminates the need for field welding and joint assembly, providing a leak-free, high-integrity solution for demanding industrial environments.

As a critical component in thermal management systems, the Coiltube delivers superior surface-area-to-volume ratios, making it indispensable in evaporators, condensers, heat exchangers, and refrigeration coils. The continuous coil geometry ensures uniform fluid distribution, reduced pressure drop, and enhanced thermal transfer efficiency compared to straight-tube alternatives.

Material & Properties

The Coiltube is fabricated from high-grade austenitic and duplex stainless steel grades, selected to meet the rigorous demands of corrosion resistance, mechanical strength, and thermal conductivity across a wide operating temperature range.

Specifications

Parameter Specification / Range Standard Reference
Outer Diameter (OD) 3.0 mm – 50.8 mm (⅛" – 2") ASTM A269
Wall Thickness 0.3 mm – 3.0 mm (0.012" – 0.118") ASTM A269
Coil Pitch (Helix Pitch) 6.0 mm – 50.0 mm Custom / Customer Drawing
Coil Length (Unwound) 1.0 m – 100.0 m (continuous) —
Coil Diameter 100 mm – 2000 mm —
End Condition Plain end, flared end, or crimped end —
Tolerance on OD ±0.05 mm – ±0.15 mm ASTM A269
Tolerance on Wall Thickness ±10% of nominal ASTM A269
Material Grades Available 304, 304L, 316, 316L, 321, 347, 904L, 2205, 2507 ASTM / EN / JIS
Surface Treatment Pickled & Passivated (P&P), Electropolished, BA ASTM A967
Heat Treatment Solution annealed (1010–1150°C), stress-relieved ASTM A778

Manufacturing Process

The production of the Stainless Steel Coiltube at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorous, multi-stage manufacturing workflow designed to ensure dimensional accuracy, metallurgical integrity, and consistent product quality:

  1. Raw Material Selection & Incoming Inspection: Stainless steel seamless tube stock is procured from certified mills and subjected to spectroscopic analysis (OES), hydrostatic testing, and dimensional verification prior to processing.
  2. Tube Straightening & Annealing: Incoming tube coils are straightened and solution-annealed at controlled temperatures (1010–1150°C) to relieve residual stresses and restore full ductility for forming operations.
  3. Coil Forming (Helical Winding): The straightened tube is fed through precision forming dies on CNC-controlled coiling machinery to produce the desired helical or spiral geometry. Forming parameters (pitch, diameter, bend radius) are programmatically controlled to ±0.1 mm accuracy.
  4. Intermediate Annealing: Where required, formed coils undergo interpass annealing to prevent work-hardening and ensure consistent mechanical properties throughout the coil length.
  5. End Processing: Coil ends are trimmed, deburred, and optionally flared, crimped, or threaded to facilitate direct integration into heat exchanger headers or process manifolds.
  6. Surface Treatment: Final pickling and passivation (per ASTM A967) removes scale and oxidation, establishing a chromium-rich passive film for maximum corrosion resistance. Electropolishing is available for sanitary-grade applications (Ra ≤ 0.4 μm).
  7. Quality Control & Testing: Each coil undergoes 100% visual inspection, dimensional verification (OD, wall thickness, pitch, coil diameter), hydrostatic pressure testing (1.5× working pressure), and selective eddy current or ultrasonic NDT (Non-Destructive Testing).
  8. Packaging & Dispatch: Finished coils are individually wrapped in protective film, secured on wooden or steel pallets, and labeled with material traceability documentation prior to shipment.

Applications

The Stainless Steel Coiltube finds extensive application across multiple industrial sectors due to its unique combination of corrosion resistance, thermal efficiency, and mechanical reliability:

Quality Certifications & Standards Compliance

Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring full traceability and regulatory compliance:

Unique Selling Points

1. Leak-Free Continuous Construction: The monolithic coil design eliminates field-welded joints, significantly reducing the risk of leakage in critical process applications.

2. Optimized Thermal Performance: The helical geometry provides up to 40% greater heat transfer surface area per unit volume compared to equivalent straight-tube configurations, enabling compact and efficient heat exchanger designs.

3. Customization Capability: Full customization of coil pitch, diameter, tube dimensions, material grade, and end conditions to meet specific engineering drawings and performance requirements.

4. Superior Corrosion Resistance: Available in grades 316L, 904L, and Duplex 2205/2507 for the most aggressive chemical and marine environments, ensuring extended service life and reduced maintenance intervals.

5. Complete Traceability: Each coil is accompanied by full material traceability documentation, including mill certificates, heat numbers, chemical analysis reports, and mechanical test results.

6. Sanitary-Grade Options: Electropolished finishes meeting 3-A, FDA, and EHEDG standards for food-grade and pharmaceutical applications.

Technical Notes & Recommendations

When specifying the Stainless Steel Coiltube for a given application, engineers should consider the following design parameters:

Document Reference: Product Code 1704 | Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd. | Classification: Technical Literature — Coiltube Cooler Bibliography & Study Reference