Stainless Steel Coil Tube — FDA 21 CFR 177.2600 Food Contact Compliance

1. Product Overview

The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered continuous stainless steel tubing product designed specifically for food-grade applications in the food and beverage processing industry. This product is engineered to meet the stringent requirements of 21 CFR 177.2600 (Code of Federal Regulations, Title 21, Chapter I, Part 177, Subpart B, Section 2600), which governs rubber articles intended for food contact.

While the primary stainless steel coil tube body is manufactured to meet general food-grade stainless steel standards, the integral rubber seals, gaskets, O-rings, and associated elastomeric components incorporated into the coil tube assembly are formulated and certified in strict compliance with FDA 21 CFR 177.2600. This ensures that all materials in direct or indirect contact with food products — including the rubber seals used in fittings, valves, and connection points of the tubing system — are safe, non-toxic, and free from harmful migration of substances into foodstuffs.

This product represents a complete food-safe piping solution where every component — from the austenitic stainless steel coil to the elastomeric sealing elements — has been evaluated and certified for food contact compliance under U.S. federal regulations.

2. Material & Properties

2.1 Stainless Steel Coil Tube Body

2.2 Rubber Sealing Components (FDA 21 CFR 177.2600 Compliant)

The elastomeric components — including O-rings, gaskets, seals, and vibration dampening elements — are manufactured using food-grade synthetic rubber compounds that comply with the specific requirements of 21 CFR 177.2600. These components are critical for maintaining system integrity, preventing leaks, and ensuring that no harmful substances migrate into food products during processing.

2.3 Physical & Mechanical Properties

3. Specifications

Parameter Specification / Value
Product Name Stainless Steel Coil Tube (Coiltube)
Material (Tube Body) 304 / 316L Austenitic Stainless Steel
Material (Seals & Gaskets) Food-grade Silicone (VMQ), EPDM, FKM, or NBR
Outer Diameter (OD) 3.18 mm – 50.8 mm (1/8" – 2")
Wall Thickness 0.3 mm – 3.0 mm
Coil Length 10 m – 100 m (continuous coil)
Surface Roughness (Ra) ≤ 0.5 μm (electro-polished)
Pressure Rating Up to 1.6 MPa (PN16) at ambient temperature
Operating Temperature −40°C to +250°C (depending on seal material)
FDA Compliance 21 CFR 177.2600 — Rubber Articles for Food Contact
Stainless Steel Compliance 21 CFR 178.3295 / 178.3297 (as applicable)
EU Compliance EC No 1935/2004, EC No 1937/2004 (Nickel migration limits)
Hygienic Design 3-A Sanitary Standards (ANSI/3-A) compatible
End Finishing Plain, beveled, or threaded with food-grade seal integration
Coating None (bare stainless steel with passivated surface)
Packaging Food-grade PE wrap, wooden or steel coil stand

4. Manufacturing Process

4.1 Stainless Steel Coil Tube Production

  1. Raw Material Selection: Certified food-grade 304 or 316L stainless steel strip is sourced from mill-certified suppliers, with full traceability of chemical composition and mechanical properties.
  2. Coil Winding: The stainless steel strip is wound into a precise coil configuration using CNC-controlled coiling equipment to ensure uniform dimensions and minimal residual stress.
  3. Welding (if applicable): For welded coil tubing, orbital TIG welding (Tungsten Inert Gas) is employed with internal and external argon shielding to produce a fully austenitic weld microstructure free from sensitization.
  4. Surface Treatment: The coil tube undergoes mechanical polishing followed by electro-polishing (electrochemical finishing) to achieve a mirror-like surface finish with Ra ≤ 0.5 μm, eliminating crevices and pits where bacteria could accumulate.
  5. Passivation: A citric acid or nitric acid passivation treatment is applied to form a stable chromium oxide layer on the surface, enhancing corrosion resistance and food safety.
  6. Dimensional Inspection: Automated optical and ultrasonic inspection systems verify OD, wall thickness, and straightness tolerances in accordance with ASTM A269/A270 standards.

4.2 Rubber Seal Component Production

  1. Material Formulation: Food-grade elastomer compounds are formulated strictly in accordance with the material specifications listed in the applicable tables of 21 CFR 177.2600. Only FDA-approved base polymers, fillers, and additives are used.
  2. Compounding & Mixing: The raw materials are mixed in a food-grade production environment using two-roll open mixers or Banbury mixers, with strict batch control and documentation.
  3. Molding: Seals and gaskets are manufactured using compression molding, injection molding, or transfer molding techniques, with precise temperature and pressure control to ensure dimensional accuracy and material homogeneity.
  4. Curing: Vulcanization is performed at controlled temperatures (typically 150°C–200°C) to achieve optimal cross-link density and mechanical properties.
  5. Post-Curing (Conditioning): A post-cure aging process is conducted to stabilize the polymer structure and reduce any residual volatiles that could contribute to food contact migration.
  6. Quality Testing: Each batch undergoes rigorous testing for total migration, specific substance migration, extractables analysis, and sensory evaluation (odor and taste) in accordance with FDA and EU testing protocols.
  7. Assembly Integration: The certified rubber seals are assembled into the stainless steel coil tube fittings and connection points in a cleanroom environment to prevent contamination.

4.3 Final Assembly & Quality Control

  1. Hydrostatic Pressure Testing: Each coil tube assembly is subjected to hydrostatic pressure testing at 1.5× the rated working pressure for a minimum of 30 minutes to verify leak-tightness.
  2. Visual Inspection: Comprehensive visual and magnification inspection of all food contact surfaces, including rubber seals, to ensure no defects, cracks, or contamination are present.
  3. Documentation & Traceability: Full traceability documentation is maintained, including material certificates, batch records, test reports, and compliance declarations for both the stainless steel tube and rubber components.
  4. Final Packaging: Products are wrapped in food-grade polyethylene film and packed on clean wooden or steel coil stands, with accompanying compliance documentation and certificates of analysis.

5. Applications

The Stainless Steel Coil Tube with FDA 21 CFR 177.2600-compliant rubber seals is designed for demanding food-grade applications where the integrity of the piping system and the safety of food contact materials are paramount. Key application areas include:

6. Quality Certifications & Compliance

The Stainless Steel Coil Tube product and its associated rubber seal components are certified and compliant with the following international standards and regulations: