Stainless Steel Spiral Coil Tube (Coiltube) — Technical Specification

1. Product Overview

The Stainless Steel Spiral Coil Tube (referred to herein as "Coiltube") is a precision-engineered tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is produced through a continuous forming and coiling process utilizing a Four-Wheel Large Spiral Coiling Machine (Four-Wheel Large Spiral Coil Tube Forming Machine), which enables the creation of long-length, uniform-diameter spiral coil tubes with exceptional dimensional accuracy and surface finish quality.

The Coiltube product line represents a specialized segment of the stainless steel pipe industry, designed to meet the demands of applications requiring extended pipe lengths, compact storage, and consistent mechanical and corrosion-resistant properties. The manufacturing methodology—centered on the four-wheel spiral coiling technology—ensures superior coil geometry, minimal residual stress, and high production efficiency compared to conventional cut-and-bend methods.

2. Material & Properties

2.1 Base Material Grades

2.2 Mechanical Properties (Typical Values for AISI 316L)

2.3 Physical Properties

3. Specifications

Parameter Specification Range Unit
Outer Diameter (OD) 3.0 – 325.0 mm
Wall Thickness 0.3 – 20.0 mm
Coil Diameter (CD) 500 – 3,000 mm
Coil Length (Continuous) 50 – 500+ m
OD Tolerance ±0.5% (fine tolerance available: ±0.2%) —
Wall Thickness Tolerance ±10% (fine tolerance available: ±5%) —
Spiral Pitch Tolerance ±2.0 mm
Surface Finish (Ra) 0.4 – 2.0 (mirror finish available: ≤ 0.2) μm
Surface Treatment Options 2B, BA, No.4, No.8, Mirror, Hairline —
End Preparation Plain end, Beveled end (37.5°), Flanged, Threaded —
Maximum Production Speed 15 – 30 m/min

4. Manufacturing Process

4.1 Process Overview

The Coiltube product is manufactured using a Four-Wheel Large Spiral Coiling Machine (Four-Wheel Large Spiral Coil Tube Forming Machine), a specialized continuous forming system that integrates tube forming, spiral coiling, and quality control into a single production line. The process flow is as follows:

  1. Raw Material Inspection: Incoming stainless steel strip or seamless tube blanks undergo 100% chemical composition verification (via Optical Emission Spectroscopy, OES) and mechanical property testing.
  2. Surface Preparation: Pickling and passivation treatment to remove scale, oxidation, and contaminants, ensuring a clean chromium-rich passive surface layer.
  3. Forming Die Setup: Calibration of the four-wheel forming mechanism to achieve the target outer diameter and wall thickness with controlled deformation.
  4. Continuous Spiral Coiling: The tube blank is fed through precision rollers and formed into a continuous spiral coil. The four-wheel system provides superior control over coil diameter, pitch uniformity, and tube cross-sectional geometry compared to conventional two-wheel or three-wheel coilers.
  5. In-Process Quality Monitoring: Real-time measurement of OD, wall thickness, and coil geometry using ultrasonic thickness gauges and laser diameter sensors.
  6. Post-Coiling Inspection: Visual examination, dimensional verification, and optional hydrostatic testing (at 2.5× working pressure) or magnetic particle inspection (MPI) for surface defect detection.
  7. End Processing: Cutting, beveling, threading, or flanging as specified by the customer's engineering requirements.
  8. Packaging & Dispatch: Protective wrapping, moisture-absorbent packaging, and secure crating for international shipment.

4.2 Four-Wheel Spiral Coiling Technology — Key Advantages

The Four-Wheel Large Spiral Coiling Machine represents an advanced evolution in coil tube forming technology. Compared to traditional coiling methods, this system offers:

  • Superior Geometric Accuracy: The four-wheel configuration provides symmetrical force distribution, resulting in more uniform coil pitch (±2.0 mm tolerance) and reduced ovality of the tube cross-section.
  • Reduced Residual Stress: Balanced forming forces minimize internal residual stresses, improving the fatigue life and dimensional stability of the finished Coiltube product.
  • Enhanced Productivity: Continuous production speeds of 15–30 m/min with minimal downtime for die adjustment, enabling high-volume output with consistent quality.
  • Wider Processing Range: Capable of handling both smaller-diameter precision coils and large-diameter heavy-wall coils within a single machine configuration.
  • Improved Surface Integrity: Reduced contact points and optimized roller geometry minimize surface scratches and deformation marks on the tube exterior.

5. Applications

5.1 Industrial Applications

5.2 Unique Selling Points

6. Quality Certifications & Compliance

6.1 Quality Management System

6.2 Product Standards & Compliance

6.3 Testing & Inspection Protocols

6.4 Industry-Specific Certifications

7. Packaging & Delivery

8. Technical Support & Customization

Wenzhou Jixing Metal Materials Co., Ltd provides comprehensive technical support services including:

Note: All specifications listed in this document are based on standard production capabilities. Custom specifications, tolerances, and performance requirements should be discussed directly with Wenzhou Jixing Metal Materials Co., Ltd to ensure full alignment with project requirements. Technical data sheets and material certifications are available upon request.