3i Stainless Steel Seamless Capillary Coiled Tubing for Gas Chromatography Systems

Overview

3i Stainless Steel Seamless Capillary Coiled Tubing is a precision-engineered fluidic pathway component designed specifically for high-integrity gas chromatography (GC) systems. Unlike welded or seam-welded alternatives, this tubing is manufactured via cold-drawing of solid stainless steel billets—ensuring full metallurgical continuity across its entire length. Its seamless construction eliminates potential leak paths, micro-crevices, and weld-induced inclusions that may compromise carrier gas purity, column conditioning stability, or baseline noise performance in trace-level analysis. The tubing is supplied in fully annealed (soft) condition following bright-annealing, which preserves surface passivation and minimizes extractable metallic ions—critical for maintaining GC system inertness, especially in sensitive applications such as residual solvent analysis (USP ), environmental VOC profiling, or petrochemical hydrocarbon speciation. Compatible with standard GC oven mounting configurations and pneumatic/pneumo-hydraulic pressure regulation up to 100 psi, it serves as both transfer line conduit and modular interconnection tubing between injectors, columns, detectors, and auxiliary gas modules.

Key Features

• True seamless structure—no weld seams, no heat-affected zones, no risk of micro-leakage at joints or bends
• Bright-annealed surface finish providing low surface energy, minimal active sites, and enhanced resistance to adsorption of polar analytes
• Controlled dimensional tolerances: ±0.05 mm on outer diameter and wall thickness—ensuring consistent flow dynamics and pressure drop predictability
• Full material traceability per ASTM A269/A213/SA-312, with certified mill test reports (MTRs) available upon request
• Available in multiple high-purity alloys—including TP316L (low carbon, superior chloride resistance), Monel 400 (excellent resistance to HF and reducing acids), and Inconel 600 (high-temperature stability up to 1000°C)
• Supplied in continuous coils up to 1000 meters, enabling field-cut customization without introducing additional fittings or dead volumes

Sample Compatibility & Compliance

The tubing exhibits broad chemical compatibility across common GC carrier gases (He, H₂, N₂) and sample matrices including halogenated solvents, aromatic hydrocarbons, amines, and sulfur-containing compounds. Its TP316L and Monel variants are routinely specified in regulated environments requiring compliance with USP , ASTM E260, and ISO/IEC 17025-accredited method validation protocols. All grades meet ASTM A269 requirements for seamless austenitic stainless steel tubing intended for general corrosion-resistant service, while bright-annealing aligns with ASTM A480 practices for surface quality control. No lubricants or drawing compounds remain post-fabrication—verified by helium leak testing (<1×10⁻⁹ atm·cm³/s) and ultrasonic cleaning validation.

Software & Data Management

While the tubing itself is a passive hardware component, its dimensional consistency and material integrity directly support robust chromatographic data acquisition. When integrated into GC systems compliant with FDA 21 CFR Part 11, the use of certified seamless tubing contributes to audit-ready system suitability records—particularly for parameters such as retention time reproducibility (RSD <0.1%), peak symmetry (tailing factor 72 h). Traceability documentation—including batch-specific MTRs, heat numbers, and dimensional inspection reports—can be digitally archived within LIMS or ELN platforms to satisfy GLP/GMP documentation requirements.

Applications

• Carrier gas delivery lines in split/splitless injectors and oven-mounted detector interfaces
• Make-up gas conduits for FID, ECD, and NPD detectors
• Transfer lines in thermal desorption (TD)–GC coupling and purge-and-trap systems
• Modular plumbing for multi-dimensional GC (GC×GC) and heart-cutting configurations
• High-temperature applications requiring sustained operation above 300°C (e.g., polymer additive analysis, heavy hydrocarbon fractionation)
• Corrosive environment deployments where chlorine, hydrogen sulfide, or organic acids are present

FAQ

Is this tubing suitable for ultra-high-purity (UHP) carrier gas applications?

Yes—bright-annealed seamless construction minimizes particulate shedding and surface outgassing, meeting ASTM D7251 and CGA G-4.1 specifications for UHP gas distribution.
Can I order custom lengths or pre-bent configurations?

Standard supply is in continuous coils; however, precision cut-to-length and mandrel-bent assemblies (with radius ≥5×OD) are available under OEM agreement.
Do you provide certification for regulatory submissions?

Mill Test Reports (ASTM A269, A213), dimensional inspection certificates, and helium leak test reports are provided with each shipment.
What is the maximum recommended operating pressure at 250°C?

For 6×1 mm TP316L tubing, the allowable working pressure per ASME B31.3 is 12.4 MPa (1800 psi) at ambient temperature; derating to ~8.5 MPa (1230 psi) applies at 250°C.
How does seamless tubing compare to electropolished fused silica in inertness?

Stainless steel offers superior mechanical durability and thermal stability; fused silica excels in absolute inertness for highly reactive species—selection depends on application priorities: ruggedness vs. ultimate surface neutrality.