Stainless Steel Coil Tube — 90° Flange Flanging Test (管端翻边90°)
Product Overview
The 90° Flange Flanging Test (管端翻边90°) is a critical process performance inspection (工艺性能检测) performed on stainless steel coil tubes (盘管, Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This test evaluates the end-face ductility (端面延展性) and edge quality (边缘质量) of the tube, verifying the suitability of the material for flange flanging connection processes (法兰翻边连接工艺). As a fundamental quality assurance procedure, the 90° flanging test ensures that stainless steel coil tubes maintain structural integrity, dimensional accuracy, and surface integrity under the deformation demands of flange-based mechanical joining methods.
This inspection is classified under Process Performance (工艺性能) within the broader category of Testing Items (检测项目), specifically addressing the Roll Edge Test (卷边试验) subdivision. The test is essential for confirming that the tube end can undergo controlled plastic deformation without cracking, tearing, or excessive thinning, thereby guaranteeing reliable performance in downstream fabrication and assembly operations.
Material & Properties
Stainless steel coil tubes subjected to the 90° flanging test are typically fabricated from austenitic stainless steel grades, which exhibit superior ductility and formability characteristics necessary for successful flanging operations. The material properties are as follows:
- Grade Composition: Common grades include 304 (AISI 304 / SUS304), 304L (AISI 304L / SUS304L), 316 (AISI 316 / SUS316), 316L (AISI 316L / SUS316L), and 321 (AISI 321 / SUS321), selected based on application-specific corrosion resistance and mechanical requirements.
- Chemical Composition (Typical for Grade 304): Carbon (C) ≤ 0.08%, Chromium (Cr) 18.0–20.0%, Nickel (Ni) 8.0–10.5%, Manganese (Mn) ≤ 2.0%, Silicon (Si) ≤ 1.0%, Phosphorus (P) ≤ 0.045%, Sulfur (S) ≤ 0.030%.
- Mechanical Properties: Tensile strength (抗拉强度) ≥ 520 MPa, Yield strength (屈服强度) ≥ 205 MPa, Elongation (延伸率) ≥ 40% (minimum), which collectively ensure adequate plastic deformation capacity for the 90° flanging operation.
- Formability Index: The material must demonstrate sufficient n-value (strain hardening exponent) and r-value (plastic strain ratio) to accommodate the localized deformation inherent in flanging without premature failure.
- Surface Condition: Bright annealed (BA), pickled and passivated (2B), or custom surface finishes that resist surface cracking during the flanging process.
Specifications
| Parameter | Specification / Requirement | Standard Reference |
|---|---|---|
| Test Designation | 90° Flange Flanging (管端翻边90°) | ASTM E1015 / GB/T 4237 |
| Flanging Angle | 90° (±2° tolerance) | ASTM E1015 |
| Tube Outer Diameter | 6.0 mm – 219.0 mm (typical range) | ASTM A554 / GB/T 12771 |
| Wall Thickness | 0.5 mm – 10.0 mm (typical range) | ASTM A554 / GB/T 12771 |
| Acceptance Criteria — Cracking | No visible cracks, tears, or splits on the flanged edge or tube surface | ASTM E1015, Section 8 |
| Acceptance Criteria — Edge Quality | Smooth, uniform flange profile; no excessive thinning (wall reduction ≤ 15% of original) | GB/T 4237, Section 7 |
| Acceptance Criteria — Surface Defects | No surface roughening, folding, or galling on the flanged zone | ISO 3497 |
| Test Temperature | Ambient temperature (20°C ± 5°C) unless otherwise specified | ASTM E1015, Section 5 |
| Sample Preparation | Cross-sectional cut perpendicular to tube axis; edge deburred and cleaned | ASTM E1015, Section 4 |
| Material Condition | As-supplied (cold-rolled and annealed) or heat-treated as specified | ASTM A554, Section 4 |
Manufacturing Process
The 90° flanging test on stainless steel coil tubes follows a rigorously defined procedure to ensure consistent, repeatable, and reliable results:
- Sample Selection and Preparation: A representative sample is cut from the coil tube (盘管) at a specified location along the coil length, ensuring the cut is perpendicular to the longitudinal axis of the tube. The cut edge is deburred, cleaned of burrs, oxides, and contaminants using appropriate mechanical or chemical methods to prevent artifacts during testing.
- Dimensional Verification: The outer diameter (OD), inner diameter (ID), and wall thickness (WT) of the sample are measured using calibrated micrometers or ultrasonic thickness gauges. Measurements are taken at multiple circumferential positions and along the sample length to confirm dimensional uniformity.
- Flanging Fixture Setup: A flanging die or forming tool is selected to match the tube's outer diameter and wall thickness. The tool geometry is designed to produce a precise 90° flange angle without introducing unintended stress concentrations.
- Flanging Operation: The tube end is clamped securely in the fixture, and controlled mechanical or hydraulic force is applied to progressively deform the tube end to a 90° angle. The operation is performed at a controlled speed to simulate standard manufacturing conditions and avoid dynamic loading effects.
- Post-Flanging Inspection: The flanged end is examined visually and, where necessary, using magnification (typically 5× to 10×) for:
- Crack Detection: Presence of any cracks, splits, or tears on the inner flange surface, outer surface, or along the flange edge.
- Edge Quality: Smoothness and uniformity of the flanged edge; absence of folding, galling, or localized thinning exceeding 15% of the original wall thickness.
- Dimensional Accuracy: Flange angle verification (90° ± 2°) and measurement of the formed flange height and diameter.
- Surface Integrity: Absence of surface roughening, scratches, or other surface defects introduced during the flanging process.
- Result Documentation: All measurements, observations, and pass/fail determinations are recorded in accordance with the applicable quality management system (e.g., ISO 9001:2015). Any non-conforming results trigger a root cause analysis and corrective action procedure.
Applications
The 90° flange flanging test is a prerequisite quality gate for stainless steel coil tubes destined for applications requiring reliable flange-based mechanical connections. Key application sectors include:
- Process Engineering and Chemical Processing: Flanged pipe connections in chemical plants, refineries, and pharmaceutical manufacturing where leak-tight, corrosion-resistant joints are critical for handling aggressive media.
- Food and Beverage Industry: Sanitary-grade flange connections in dairy, brewing, and food processing lines where CIP (Clean-in-Place) and SIP (Sterilize-in-Place) compatibility is essential.
- Oil and Gas Industry: Flange connections in upstream and midstream processing facilities, including separator vessels, heat exchangers, and pipeline manifolds.
- Power Generation: Flanged piping systems in nuclear, thermal, and renewable energy plants where material reliability under cyclic thermal and pressure loading is paramount.
- Automotive and Aerospace: Flanged exhaust systems, fuel lines, and hydraulic connections requiring high-temperature resistance and fatigue durability.
- Construction and Architectural Engineering: Structural flange connections in marine, offshore, and high-rise construction where corrosion resistance and long-term mechanical integrity are required.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains comprehensive quality certifications and adheres to internationally recognized standards to ensure the reliability and traceability of stainless steel coil tube products:
- ISO 9001:2015 — Quality Management Systems: Certifies the company's commitment to consistent quality management, continuous improvement, and customer satisfaction across all manufacturing and testing processes.
- ISO 14001:2015 — Environmental Management Systems: Demonstrates environmental responsibility in material sourcing, manufacturing, and waste management practices.
- ISO 45001:2018 — Occupational Health and Safety Management: Ensures safe working conditions and responsible operational practices throughout the supply chain.
- EN 10204 — Delivery Inspection Documents: Provides Type 3.1 and Type 3.2 inspection certificates confirming material conformity with specified standards, including chemical composition, mechanical properties, and process performance test results.
- ASTM A554 / A554M — Standard Specification for Stainless Steel Tubing, Cold-Drawn: Governs the material requirements, chemical composition, mechanical properties, and testing protocols for cold-drawn stainless steel tubing.
- GB/T 12771 — Technical Conditions for Delivery of Stainless Steel Seamless Tubes and Cold-Drawn Tubes: The national Chinese standard specifying requirements for manufacturing, testing, and delivery of stainless steel tubing.
- ASTM E1015 — Standard Test Method for Flanging Tubing, Pipe, and Sheet (Flange Flanging Test): The primary international standard defining the methodology, acceptance criteria, and reporting requirements for the 90° flange flanging test.
- MTC (Material Test Certificate): Each batch of stainless steel coil tubes is accompanied by a comprehensive MTC detailing heat numbers, chemical analysis, mechanical test results, and process performance test outcomes including the 90° flanging test.
Unique Selling Points
- End-to-End Traceability: Every coil tube batch undergoes the 90° flanging test with full documentation traceable to individual heat numbers, ensuring complete supply chain transparency and accountability.
- Multi-Grade Capability: Testing protocols are validated across a wide range of austenitic stainless steel grades (304, 304L, 316, 316L, 321, 310S, etc.), enabling customers to source material confidence for diverse application requirements.
- Integrated Quality Assurance: The flanging test is one component of a comprehensive process performance evaluation suite that includes bending tests, expansion tests, and impact tests, providing a holistic assessment of material formability.
- Flange Connection Readiness: By verifying flange flanging performance at 90°, Wenzhou Jixing guarantees that their coil tubes are field-ready for flange-based mechanical connections, reducing installation risks and ensuring leak-tight, durable joints in critical applications.
- Compliance with Global Standards: Products are manufactured and tested to meet both international (ASTM, EN, ISO) and Chinese national (GB/T) standards, facilitating seamless integration into global supply chains and regulatory frameworks.
Note: The 90° Flange Flanging Test (管端翻边90°) is a non-destructive verification of material formability that directly correlates to the long-term reliability of flange-based mechanical connections. Wenzhou Jixing Metal Materials Co., Ltd. employs state-of-the-art testing equipment and certified personnel to ensure that every stainless steel coil tube product meets the highest standards of quality, safety, and performance for demanding industrial applications worldwide.