Pressure Direction
Positive-pressure supply and negative-pressure extraction impose different structural demands. The wrong format can lead to collapse, excessive movement or poor airflow.
Underground Airflow Systems
Mine Ventilation Ducting Built Around the Air Route
Project-configured flexible ducting for fresh-air supply, contaminated-air extraction and temporary underground ventilation—specified by pressure direction, fan duty, route geometry and connection method.
DERFLEX supplies finished mine ventilation duct sections and PVC-coated ducting materials for mines, tunnels, shafts and underground construction. Performance options are confirmed against the project specification and applicable test method before production.
Mine-Specific Product Definition
Flexible Air Distribution for Advancing Underground Work
Mine ventilation ducting forms the temporary or semi-permanent air path between an auxiliary fan and an underground working area. The duct may deliver fresh air toward a heading, draw dust or fumes away from an equipment zone, or connect a changing route where rigid duct would be slow to extend and difficult to store.
The correct construction depends first on airflow direction. A collapsible layflat tube is commonly used for forced-air supply because internal pressure inflates the duct. Suction or exhaust duty generally requires rings or a continuous wire helix so the duct does not collapse under negative pressure. Where headroom is limited, an oval or twin-chamber arrangement can reduce the occupied vertical space.
DERFLEX combines PVC-coated technical textile, welded fabrication, reinforcement and project-defined fittings into finished mine air duct sections. This makes it possible to coordinate the fabric body, seam, suspension, coupling and route details as one purchasing package instead of treating each component separately.
Finished Flexible Mine Duct Section
Collapsible body, fabricated edge and selected connection details can be supplied to project drawings.
What the System Must Control
Six Variables That Shape Underground Duct Performance
Airflow efficiency and service life are influenced by the complete duct system, not by fabric weight alone.
Leakage Management
Weld quality, end cuffs and coupling selection influence how much fan output reaches the active heading over a long duct run.
Route Geometry
Diameter, bends, elevation changes, low-clearance passages and moving work fronts affect the recommended duct type and accessory layout.
Abrasion Exposure
Rock contact, handling and repeated relocation can concentrate wear at the underside, suspension points, couplings and bends.
Site Safety Requirements
Flame-retardant and antistatic options should be matched to the required project standard, test method and operating environment.
Installation Rhythm
Section length, packaging, suspension spacing and connection speed matter when the air line must advance with the mine or tunnel face.
Product Architecture
Select Mine Ventilation Ducting by Airflow Mode
Each product can be configured by diameter, length, coupling, suspension and treatment requirements.
Forced-Air Supply
Layflat Positive-Pressure Ducting
Collapsible air-forcing sections for carrying fresh air along mine headings and advancing tunnel routes. Compact when packed and inflated by the fan during operation.
View layflat positive-pressure duct →
Extraction & Suction
Spiral Wire-Reinforced Ducting
A continuous helix helps the duct retain shape under negative pressure, through bends and at equipment connections. Wear strips and reinforced cuffs are available.
View spiral wire-reinforced duct →
Low Headroom
Oval or Twin-Chamber Ducting
Alternative profiles can be considered where round ducting interferes with vehicles, services or roof clearance. The layout should be reviewed with the available opening and required airflow.
Compare low-headroom selection factors →
System Completion
Transitions, Elbows and Couplings
Reducers, branch pieces, end cuffs, zippers, rings, clamps, suspension points and wear reinforcements can be coordinated around the route and installation method.
Review custom duct accessories →
Material & Fabrication
A Duct Body Engineered as a Working Assembly
DERFLEX can supply coated material or completed duct sections, allowing the product structure to be selected around the intended fabrication and field use.
PVC-Coated Polyester Base
Industrial filament fabric provides the load-bearing structure, while the PVC coating supports air containment, moisture resistance and weldable fabrication.
Welded Longitudinal and End Seams
Hot-air or high-frequency welding can create continuous seams selected for the fabric construction and duct geometry.
Reinforced High-Stress Zones
Suspension points, end cuffs, zipper areas and contact zones can receive extra layers or wear strips where repeated loading is expected.
Project-Specific Surface Treatment
Flame-retardant, antistatic, cold-weather, high-visibility or abrasion-oriented formulations can be discussed against a defined test requirement.
Typical Flexible Duct Construction
The final layer arrangement varies with the selected material, pressure duty and reinforcement system.
Outer PVC SurfaceWeather, moisture and handling protection; optional lacquer or special finish.
High-Tenacity Polyester ScrimControls tensile load, tear propagation and dimensional stability.
Inner PVC SurfaceSmooth air path designed to support containment and welded seam construction.
Optional Structural SupportSteel rings or continuous helix for shape retention under suction or tight routing.
Configurable Technical Range
Reference Specifications for Quotation
The values below describe common project options. Final selections depend on pressure calculations, route layout, required tests and production confirmation.
| Specification Item | Typical Project Options | Selection Considerations |
|---|---|---|
| Product Form | Finished layflat duct, ring-supported duct, spiral-wire duct, oval/twin duct or coated fabric roll | Choose by positive or negative pressure and required field assembly |
| Duct Body Material | PVC-coated polyester technical textile; project-selected weight and yarn construction | Pressure, abrasion, handling frequency, flame/antistatic requirement and service life |
| Diameter | Approximately 300–3000 mm; custom sizes subject to engineering review | Required airflow, available headroom, fan curve and route losses |
| Section Length | 5–100 m common fabrication range; longer sections can be discussed | Installation rhythm, handling weight, storage and coupling frequency |
| Reinforcement | None, periodic rings, continuous steel-wire helix, reinforced wear strip | Pressure direction, bends, suction duty and contact exposure |
| Connections | Zipper, hook-and-loop, steel ring, clamp, eyelet, sleeve or drawing-based interface | Leakage target, installation speed, compatibility and maintenance access |
| Suspension | D-rings, eyelets, reinforced fin, cable clips or custom hanger spacing | Duct weight, route curvature, ceiling condition and dynamic movement |
| Performance Options | Flame-retardant, antistatic, cold-resistant, high-visibility, abrasion-oriented and custom color | Must be linked to a written project requirement and agreed test method |
| Pressure Capability | Defined by completed duct construction rather than fabric weight alone | Confirm fan duty, diameter, seam, reinforcement, coupling and section length |
| Inspection Documents | Dimensional, material and agreed performance records available by order requirement | Specify documentation and third-party testing needs before quotation |
Engineering note: fan power or static pressure alone is not sufficient to select a duct. The quotation should consider airflow volume, total run length, diameter, bend count, elevation, leakage allowance, connection style and local project requirements.
Fast Selection Guide
Layflat, Spiral or Low-Profile?
Use this comparison as a purchasing starting point, then confirm the completed duct design against the fan and route.
Layflat Duct
Designed primarily for positive-pressure air supply.
- Collapses flat for transport and storage
- Suitable for long, advancing fresh-air lines
- Lower structural weight than continuous-helix duct
- Requires fan pressure to retain its operating shape
Spiral-Reinforced Duct
Selected where the duct must resist collapse or route through bends.
- Supports suction and extraction duties
- Useful at fans, equipment and curved connections
- Can include wear strips and reinforced cuffs
- Bulkier to store than layflat sections
Oval / Twin Duct
Considered where vertical clearance is restricted.
- Reduces the height occupied by the air line
- Can help preserve equipment and vehicle clearance
- Requires coordinated suspension and coupling design
- Should be reviewed against actual opening geometry
Underground Applications
Mine Air Ducting for Changing Work Zones
Flexible systems are especially useful where ventilation routes move, clearances vary or rapid installation is important.
Manufacturing Control
From Coated Fabric to Packed Duct Section
Inspection points can be aligned with the purchased product form and agreed project documentation.
Requirement Review
Airflow direction, fan data, run length, route, diameter, safety options and coupling interface are clarified.
Material Matching
Base fabric, coating, weight, surface treatment and reinforcement are selected for the intended duty.
Cutting & Welding
Panels, seams, cuffs, suspension zones, zippers, rings and wear patches are fabricated to confirmed dimensions.
Inspection
Dimensions, visual seam quality, connection details and agreed tests are checked according to the order plan.
Project Packing
Sections can be labeled by diameter, length, route or installation sequence to simplify site identification.
Information to Send with Your RFQ
A more complete project brief allows the quotation to address the system rather than only a unit price per meter.
Mine or tunnel type and intended ventilation objective
Positive or negative pressure, fan model and operating point
Required airflow, total run length, diameter and route drawing
Straight sections, bends, branches, reducers and equipment connections
Preferred section length, suspension method and coupling style
Required flame, antistatic, cold, color or abrasion specification
Documentation, labeling, packaging and inspection requirements
Related DERFLEX Resources
Continue the Selection Process
These pages cover adjacent product formats, construction details and application options.
Buyer FAQ
Mine Ventilation Ducting Questions
Answers are provided as general selection guidance; final performance should be confirmed for the completed duct and project requirement.
What is the difference between positive-pressure and negative-pressure mine ducting?
Positive-pressure ducting is inflated by air pushed from the fan and is commonly supplied as a collapsible layflat tube. Negative-pressure ducting must resist collapse while air is extracted, so it normally uses steel rings or a continuous wire helix. A project using both airflow modes may require different duct constructions in different parts of the system.
Which diameter should be used for a mine ventilation duct?
Diameter should be selected from the required airflow, air velocity, pressure loss, fan curve, route length, bend count and available clearance. A larger diameter may reduce friction loss but requires more installation space. DERFLEX recommends reviewing these inputs together rather than selecting diameter from fan power alone.
Yes. DERFLEX can quote fabricated duct sections with welded seams, end cuffs, suspension points, coupling details and optional reinforcement. PVC-coated ducting fabric can also be supplied for customers that fabricate locally.
Are flame-retardant and antistatic options available?
These options can be discussed for defined project requirements. The required standard, test method, acceptance value and documentation should be identified before production because terminology and thresholds vary by market and mine type.
How can air leakage be reduced along a long duct run?
Leakage control depends on seam construction, coupling overlap, zipper or ring design, section alignment and installation practice. Fewer connections may reduce potential leakage points, while shorter sections can be easier to handle and replace. The preferred balance should be set by the route and maintenance plan.
What information is required for a custom quotation?
Please provide airflow direction, fan data, required airflow, duct diameter, total route length, section length, bends or branches, coupling preference, suspension method, operating environment and any specified flame, antistatic, cold-weather, color, labeling or inspection requirements.
Project-Based Quotation
Specify the Air Route. DERFLEX Will Configure the Duct.
Send the fan data, route length, diameter, airflow mode, connection preference and project performance requirements. The DERFLEX team will review suitable material and fabrication options for your mine ventilation ducting program.
Useful RFQ Attachments
Fan curve or model, route sketch, installation photos, existing duct sample, connection drawing, required test specification and expected order quantity.