316L / Hastelloy Seamless Coil Tube for Online pH/ORP Electrode Housing
Product Overview
The 316L / Hastelloy Seamless Coil Tube for Online pH/ORP Electrode Housing is a precision-engineered component manufactured by Wenzhou Jixing Metal Materials Co., Ltd. Specifically designed for process analysis instrumentation, this coil tube serves as a critical protective sheath for in-situ pH and oxidation-reduction potential (ORP) measurement electrodes. The product is engineered to withstand continuous direct contact with aggressive acidic and alkaline media while maintaining superior electrical insulation integrity and ensuring rapid, accurate sensor response times.
In process industries where real-time monitoring of pH and ORP values is essential for quality control, environmental compliance, and process optimization, the electrode housing coil tube must deliver unmatched corrosion resistance, mechanical durability, and reliable sealing performance. This product addresses those demanding requirements with a meticulously designed sealed structural configuration and premium-grade alloy materials.
Material & Properties
The coil tube is available in two premium material grades, each selected to meet the most stringent corrosion and performance demands of process analysis environments:
- 316L Austenitic Stainless Steel (UNS S31603): Contains 2–3% molybdenum, providing exceptional resistance to pitting and crevice corrosion in acidic and alkaline environments. The ultra-low carbon content (≤0.03% C) eliminates intergranular corrosion risks during welding and heat treatment. Typical composition: 16.5–18.5% Cr, 10.0–14.0% Ni, 2.0–3.0% Mo.
- Hastelloy Alloy (C-276 / B-3): A nickel-molybdenum-chromium superalloy offering extraordinary resistance to reducing acids, halides, and highly concentrated alkaline solutions. Hastelloy grades are recommended for extreme chemical environments where 316L may be insufficient, such as hydrochloric acid, sulfuric acid, or caustic soda solutions at elevated temperatures.
Both material grades are supplied in seamless tube form, ensuring homogeneous microstructure, absence of weld seams, and uniform corrosion resistance throughout the entire cross-section—critical for electrode housing applications where wall integrity directly impacts measurement accuracy and service life.
Key Specifications
| Parameter | Specification |
|---|---|
| Material Grades | 316L (UNS S31603), Hastelloy C-276 / B-3 |
| Tube Form | Seamless coil tube (coiled delivery) |
| Outer Diameter Range | 3.0 mm – 50.8 mm (customizable) |
| Wall Thickness Range | 0.3 mm – 3.0 mm |
| Coil Diameter | 150 mm – 500 mm (standard); custom available |
| Surface Finish | Polished / Passivated (Ra ≤ 0.8 μm) |
| Temperature Range | −40 °C to +250 °C (316L); up to +300 °C (Hastelloy) |
| Pressure Rating | Up to 4.0 MPa (design dependent) |
| Sealing Design | Integrated mechanical seal with O-ring groove or compression fitting interface |
| Standard Compliance | ASTM A269 / A270, ASTM B407 / B622, EN 10216-5 |
| Corrosion Resistance | Excellent in acidic (H₂SO₄, HCl, H₃PO₄) and alkaline (NaOH, KOH) media |
Manufacturing Process
Wenzhou Jixing Metal Materials Co., Ltd. employs a rigorous, multi-stage manufacturing process to ensure the highest quality and dimensional accuracy for electrode housing coil tubes:
- Raw Material Selection: Only certified mill-grade 316L or Hastelloy seamless pipe stock is procured, with full traceability and mill test reports (MTRs) for chemical composition and mechanical properties.
- Precision Coil Winding: Seamless tubes are cold-formed onto precision-mandrel coil winding equipment to achieve consistent curvature, uniform coil diameter, and zero kinking or ovality defects.
- Surface Polishing & Passivation: Inner and outer surfaces undergo mechanical polishing followed by acid pickling and passivation to remove scale, contaminants, and achieve a smooth, corrosion-resistant passive oxide layer.
- Sealing Structure Integration: O-ring grooves, compression fitting interfaces, or threaded seal ports are precision-machined at designated locations to ensure leak-tight performance under continuous process conditions.
- Dimensional & Non-Destructive Testing: Every coil tube undergoes dimensional verification, hydrostatic pressure testing, and visual/eddy-current inspection to confirm wall integrity and absence of defects.
- Packaging & Traceability: Coils are wrapped in protective film, labeled with heat numbers, material certifications, and dimensional data for complete traceability through the supply chain.
Applications
This coil tube product is specifically engineered for the following process analysis applications:
- Online pH Electrode Housing: Serves as the protective sheath for glass-body pH electrodes deployed in wastewater treatment plants, chemical reactors, food processing lines, and pharmaceutical manufacturing where continuous pH monitoring is required.
- Online ORP Electrode Housing: Provides a corrosion-resistant conduit for platinum/redox ORP probes used in chlorine dosing systems, boiler water treatment, electroplating baths, and environmental monitoring stations.
- Process Analysis Instrumentation: Integrates into automated control loops in petrochemical, semiconductor, power generation, and mining industries where real-time chemical analysis drives process adjustments.
- Harsh Chemical Environments: Ideal for applications involving concentrated sulfuric acid, hydrochloric acid, phosphoric acid, caustic soda, mixed acid pickling solutions, and halide-containing process streams.
- High-Response-Time Applications: The thin-wall seamless construction and smooth inner bore minimize diffusion delays, enabling rapid electrode response times critical for dynamic process control.
Unique Selling Points
- Superior Corrosion Performance: 316L and Hastelloy grades provide decades of service life in aggressive acid and alkali environments, drastically reducing maintenance intervals and unplanned shutdowns.
- Sealed Structural Design: Integrated sealing features prevent process media ingress into the electrode cable termination zone, protecting sensitive electronics and ensuring measurement reliability.
- Seamless Construction: Homogeneous material structure eliminates corrosion initiation points at weld seams, ensuring consistent wall integrity and long-term dimensional stability.
- Optimized for Response Time: Thin-wall precision manufacturing and smooth surface finish minimize ion diffusion resistance, delivering faster and more accurate pH/ORP readings.
- Coil Delivery Format: Supplied as continuous coils for on-site cutting and installation, reducing fabrication time, minimizing waste, and enabling flexible integration into various electrode housing configurations.
- Full Material Traceability: Every batch is accompanied by mill test reports, chemical analysis certificates, and dimensional inspection records for compliance with regulatory and quality assurance requirements.
Quality Certifications & Standards
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system and adheres to internationally recognized standards:
- ISO 9001:2015 — Quality Management System Certification
- ASTM A269 / A270 — Standard Specifications for Austenitic Stainless Steel Seamless Tube
- ASTM B407 / B622 — Standard Specifications for Nickel-Molybdenum Alloy (Hastelloy) Seamless Tube
- EN 10216-5 — European Standard for Non-Alloy and Stainless Steel Tubes for General Purposes
- GB/T 12771 — Chinese National Standard for Fluid Transport Stainless Steel Tubes
- Material Traceability: Full mill certification (EN 10204 3.1 / 3.2) provided for each production batch
- Non-Destructive Testing: Eddy current testing, hydrostatic pressure testing, and visual inspection performed per ASTM E309 / E747
Note: Custom specifications, including non-standard diameters, wall thicknesses, coil dimensions, and specialized sealing configurations, are available upon request. Wenzhou Jixing Metal Materials Co., Ltd. welcomes technical consultations to provide tailored solutions for specific pH/ORP electrode housing applications.