Industry-Verified Manufacturing Data (2026)

Flexible Duct

Based on aggregated insights from multiple verified factory profiles within the CNFX directory, the standard Flexible Duct used in the Machinery and Equipment Manufacturing sector typically supports operational capacities ranging from standard industrial configurations to heavy-duty production requirements.

Technical Definition & Core Assembly

A canonical Flexible Duct is characterized by the integration of Helical wire core and Inner liner. In industrial production environments, manufacturers listed on CNFX commonly emphasize Galvanized steel wire construction to support stable, high-cycle operation across diverse manufacturing scenarios.

A flexible, bendable duct used in HVAC systems to connect rigid ductwork sections and navigate around obstacles.

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Product Specifications

Technical details and manufacturing context for Flexible Duct

Definition
A flexible duct is a key component within ductwork systems that provides adaptable connectivity between rigid duct sections. It allows for installation in confined spaces, accommodates misalignments, and enables routing around structural obstacles while maintaining airflow. Typically constructed with a helical wire core and flexible insulation layers, it serves as a transitional element in ventilation, heating, and air conditioning applications.
Working Principle
Flexible ducts function by maintaining an open, continuous passage for air movement while allowing bending and compression. The helical wire reinforcement provides structural integrity to prevent collapse during airflow, while the flexible outer jacket accommodates directional changes without restricting flow. Air pressure differentials drive movement through the duct, with minimal resistance due to the smooth interior lining.
Common Materials
Galvanized steel wire, Aluminum foil, Polyester insulation, PVC or polymer outer jacket
Technical Parameters
  • Diameter range typically from 75mm to 600mm, with standard lengths of 3-10 meters (mm) Per Request
Components / BOM
  • Helical wire core
    Provides structural support and prevents collapse during airflow
    Material: Galvanized steel
  • Inner liner
    Creates smooth airflow surface and provides thermal insulation
    Material: Aluminum foil with polyester backing
  • Outer jacket
    Protects against environmental factors and provides vapor barrier
    Material: PVC or polymer
Engineering Reasoning
0-2500 Pa pressure differential, -40°C to 120°C temperature range, 0-25 m/s airflow velocity
Collapse at 3000 Pa negative pressure, rupture at 5000 Pa positive pressure, permanent deformation at 150°C for 30 minutes
Design Rationale: Plastic deformation of helical wire reinforcement exceeding yield strength (typically 250 MPa for galvanized steel wire), polymer jacket degradation via Arrhenius equation kinetics with activation energy of 80 kJ/mol for PVC materials
Risk Mitigation (FMEA)
Trigger Helical reinforcement wire corrosion reducing cross-sectional area below 70% of original
Mode: Duct collapse under normal operating pressure (500-1500 Pa)
Strategy: Galvanic protection with zinc coating thickness ≥85 μm, or substitution with 316L stainless steel wire (minimum 11% chromium content)
Trigger Polymer jacket UV degradation reducing tensile strength below 7 MPa
Mode: Longitudinal tearing along wire helix path at bend radii <2× duct diameter
Strategy: Carbon black additive at 2-3% concentration for UV absorption, or fluoropolymer coating with 50 μm minimum thickness

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Flexible Duct.

flexible HVAC duct for machinery manufacturing galvanized steel wire flexible duct aluminum foil insulated flexible duct polyester insulation flexible duct connector PVC jacket flexible duct for industrial HVAC

Applied To / Applications

This component is essential for the following industrial systems and equipment:

Ductwork
View system integration details

Industrial Ecosystem & Supply Chain DNA

Complementary Systems
Downstream Applications
Specialized Tooling

Application Fit & Sizing Matrix

Operational Limits
pressure: Up to 2.5 in. w.g. (0.09 psi) static pressure
other spec: Air velocity: Up to 4000 FPM (20 m/s), Bend radius: Minimum 1x duct diameter
temperature: -40°F to 250°F (-40°C to 121°C)
Media Compatibility
✓ Conditioned Air ✓ Ventilation Air ✓ Low-Pressure Exhaust Gases
Unsuitable: Corrosive Chemical Fumes or High-Particulate Slurries
Sizing Data Required
  • Required Airflow (CFM)
  • Available Space/Length
  • Static Pressure Drop Allowance

Reliability & Engineering Risk Analysis

Failure Mode & Root Cause
Material fatigue and cracking
Cause: Repeated flexing beyond design limits, vibration-induced stress cycles, and exposure to temperature fluctuations causing polymer degradation and metal fatigue at connection points.
Internal liner delamination and erosion
Cause: Abrasive particulate flow, chemical attack from conveyed media, moisture accumulation leading to microbial growth, and improper installation creating turbulent flow patterns that accelerate wear.
Maintenance Indicators
  • Visible sagging or distortion of duct sections indicating structural weakening or internal blockage
  • Audible flapping or whistling noises during operation suggesting liner separation, holes, or loose connections
Engineering Tips
  • Implement proper support spacing and avoid sharp bends - maintain minimum bend radius per manufacturer specifications to prevent stress concentration and material fatigue.
  • Install inspection ports at strategic locations and conduct regular internal visual inspections using borescopes to detect early signs of liner wear, corrosion, or buildup before catastrophic failure occurs.

Compliance & Manufacturing Standards

Reference Standards
ISO 10380:2012 (Metallic flexible hoses, assemblies and joints) ASTM C1338 (Standard Test Method for Determining Fungi Resistance of Insulation Materials and Facings) EN 13103 (Railway applications - Wheelsets and bogies - Non-powered axles - Design method)
Manufacturing Precision
  • Bore diameter: +/- 0.5 mm
  • Length: +/- 1.5% of total length
Quality Inspection
  • Leakage Test (Pressure test at 1.5 times working pressure)
  • Flexibility Test (Minimum bend radius verification)

Factories Producing Flexible Duct

Verified manufacturers with capability to produce this product in China

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✓ 93% Supplier Capability Match Found

P Project Engineer from Germany Feb 18, 2026
★★★★★
"Standard OEM quality for Machinery and Equipment Manufacturing applications. The Flexible Duct arrived with full certification."
Technical Specifications Verified
S Sourcing Manager from Brazil Feb 15, 2026
★★★★★
"Great transparency on the Flexible Duct components. Essential for our Machinery and Equipment Manufacturing supply chain."
Technical Specifications Verified
P Procurement Specialist from Canada Feb 12, 2026
★★★★★
"The Flexible Duct we sourced perfectly fits our Machinery and Equipment Manufacturing production line requirements."
Technical Specifications Verified
Verification Protocol

“Feedback is collected from verified sourcing managers during RFQ (Request for Quote) and factory evaluation processes on CNFX. These reports represent historical performance data and technical audit summaries from our B2B manufacturing network.”

6 sourcing managers are analyzing this specification now. Last inquiry for Flexible Duct from USA (42m ago).

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Frequently Asked Questions

What materials are used in flexible ducts for industrial applications?

Our flexible ducts feature a helical galvanized steel wire core, aluminum foil inner liner, polyester insulation layer, and durable PVC or polymer outer jacket for maximum durability in industrial environments.

How do flexible ducts help in machinery manufacturing facilities?

Flexible ducts provide essential airflow solutions by connecting rigid HVAC ductwork sections and navigating around machinery, equipment, and structural obstacles while maintaining efficient air distribution.

What are the key components in a flexible duct BOM?

The bill of materials includes three main components: helical wire core for structural support, inner liner for smooth airflow, and outer jacket for protection against environmental factors and mechanical damage.

Can I contact factories directly on CNFX?

CNFX is an open directory, not a transaction platform. Each factory profile provides direct contact information and production details to help you initiate direct inquiries with Chinese suppliers.

Data Specifications verified by CNFX Industrial Index (v2.6.03) for Machinery and Equipment Manufacturing sector.

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