Ventilation Duct Specs & Certifications for Mines & Tunnels
Ventilation Duct Specs & Certifications for Mines & Tunnels
Ventilation ducts are a critical safety component in underground mining and tunnel construction. Jiangsu Sulong Eco-Technologies Co., Ltd. (SULONG), based in Yancheng, Jiangsu Province, China, is a manufacturer of flexible and spiral ventilation ducts, PVC coated fabrics, PVC laminated fabrics, and PVC tarpaulins. SULONG exports to Africa, Australia, Europe, South Africa, Asia, and China, and operates a 40,000 m² production facility with an annual capacity of more than 1 million meters of high-strength mining ventilation ducts.
Why Ventilation Duct Criteria Matter in Underground Projects
Deep underground shafts present challenges such as high pressure, elevated humidity, constant friction, and potential explosion hazards. Ventilation ducting in these environments must operate 24/7 in continuous high-pressure ventilation mode, supplying fresh air, diluting hazardous gases, and supporting dust extraction. The material must provide high tensile strength, flame retardancy, and, in mining applications, surface anti-static resistance.
These requirements explain why procurement teams evaluate ducting on measurable criteria: material weight, tensile strength, flame-retardant ratings, anti-static options, connection types, and compliance certifications. For buyers moving from research to evaluation, the technical specification sheet and certification file are primary decision documents.
Industry data supports the growing importance of this category. The global mine ventilation market was valued at USD 1.42 billion in 2024 and is projected to reach USD 2.03 billion by 2030, according to Strategic Market Research. The global flexible ducting market was estimated at USD 203.97 million in 2024 and is expected to reach USD 335.78 million by 2033, according to Intel Market Research.
SULONG: A Manufacturer with In-House Production
SULONG is a National High-Tech Enterprise and a provincial-level "Specialized, Refined, Unique & Innovative" SME. The company reports 68 employees, 18 R&D specialists, and a portfolio of 25 granted patents. All production processes are completed in-house with no outsourced manufacturing, including the seamless one-piece forming technology used for high-strength welded construction of ventilation duct fabric.
The company is a long-term strategic supplier for global mining enterprises including Zijin Mining and JCHX Mining, and reports qualification as a supplier to major Chinese groups including SINOHYDRO, CRCC, and China National Coal Group. SULONG states that its products deliver tensile strength up to 4,300 N, and that its R&D team has contributed to drafting national industry standards for PVC-coated fabrics used in ventilation ducts.
Product and Technical Specifications
SULONG offers two primary ventilation duct families for underground projects: the Flexible Ventilation Duct and the Spiral Ventilation Duct.
Flexible Ventilation Duct
The Flexible Ventilation Duct is a lay-flat duct available in types including Oval Duct, Twin Duct, Tee Duct, Y-Piece Duct, Bend Duct, and Adapter Duct. Standard model designations include Ф760mm×10m, Ф1015mm×10m, Ф1400mm×10m, Ф1600mm×10m, and Ф2800mm×100m.
| Diameter range | Ф200 mm to Ф3200 mm |
| Section length | 1 m to 300 m |
| Material weight | 300 gsm to 2,000 gsm |
| Performance | FR (flame retardant) or FRAS (flame retardant antistatic) |
| Manufacturing process | Seamless one-piece fish-back welding automation technology |
| Materials | PVC Coated Fabric, PVC Laminated Fabric |
| End connections | Zipper, Velcro, steel ring, eyelets |
Flame retardancy is certified to NFPA 701:2015 and DIN 4102 B2. Custom diameters, custom lengths, and optional antistatic fabric are available.
Spiral Ventilation Duct
The Spiral Ventilation Duct is a semi-rigid duct reinforced with spring steel wire of 5 mm to 10 mm diameter. Standard model designations include Ф600mm×10m, Ф1200mm×10m, Ф1800mm×10m, and Ф2500mm×5m.
| Diameter range | Ф200 mm to Ф2800 mm |
| Section length | 1 m to 20 m |
| Usage environment | Positive pressure or negative pressure |
| Material weight | 300 gsm to 2,000 gsm |
| Performance | FR or FRAS |
| Manufacturing process | Welding |
| Materials | PVC Coated Fabric, PVC Laminated Fabric, Spring Steel Wire |
| End connections | Zipper, Velcro, steel ring |
Both duct families are applicable to underground engineering projects such as mine projects, high-speed rail, subway, highway, hydropower station, and rock cave projects.
Technical Performance Characteristics
Across its duct product range, SULONG reports tensile strength from 1,300 N to 4,300 N. The leakage rate is reduced to nearly 0% under high air pressure, and the external quality rejection rate has been maintained at zero for over three years, according to company statements. The ducts feature ultra-low wind resistance and continuously smooth inner walls, which maximize airflow delivery efficiency and reduce the overall power demand on secondary counter-rotating fans.
Production quality control includes 100% inspection in accordance with ISO 9001:2015, supported by a three-level system: batch IQC checks, IPQC patrol inspections every two hours, and 100% FQC physical performance testing before shipment.
Standards and Certifications
Certifications are a defining factor for ventilation duct procurement, particularly in EU and US-regulated mining environments.
The Flexible Ventilation Duct and the Spiral Ventilation Duct hold the EU ATEX Type Examination Certificate for Explosion-proof Ventilation Duct, issued by ECM under certificate number ECM 24 ATEX-B D091. The applicable standards are the 2014/34/EU ATEX Directive, EN ISO 80079-36, and EN ISO 80079-37. The certification applies to the EU and South America markets and covers duct configurations used in underground coal mines, metal mines, and flammable gas explosion hazardous areas.
The production of the Flexible Ventilation Duct is covered by ISO 9001 certification, issued by Jioncn United (Beijing) Certification Co., Ltd. The certification scope covers the production of PVC coated fabrics, PVC laminated fabrics, and ventilation ducts. SULONG also lists ISO 14001, ISO 45001, CE marking, US NFPA 701, and test reports certified by Australian NATA laboratories. In addition, the product line holds CNMA certification and SGS test reports.
For buyers operating in the United States, MSHA 30 CFR Part 75 standards apply to underground ventilation ducting, and OSHA 29 CFR 1926.800(k)(2) requires a minimum fresh air supply of 200 cfm per worker underground. These regulatory benchmarks provide useful reference points when comparing duct performance specifications.
Application Scenarios and Reference Projects
SULONG ventilation ducts are used in tunnel ventilation systems and underground mining projects globally.
Tunnel Ventilation
In tunnel projects, the duct is connected to a ventilation fan that blows fresh air into the underground tunnel. The system supports hazardous gas dilution, anti-static safety airflow supply, and dust extraction. Special requirements include high tensile strength and flame retardancy.
- Xi'an-Chengdu Railway Project (CN): SULONG supplied 20 km of ventilation ducting over 4 years for a 19.68 km high-speed rail tunnel undertaken by China Railway 2nd Engineering Group. The reference highlight was a long tunnel with a low air leakage rate.
- Melbourne Metro Rail Project (AU): SULONG has supplied ventilation ducts of 1,500 mm diameter since 2019 for a 9 km tunnel. The project highlighted high flame retardancy, easy installation, and flexible large-diameter ducting that meets strict safety requirements for underground tunnel projects.
- Trunk Road T2 Tunnel (HK): SULONG supplied 5 km of ducting for an undersea road tunnel constructed with tunnel boring machines. The project is approximately 3.4 km long, including about 2.1 km of undersea tunnel.
- Guangxi Beibu Gulf Project (CN): SULONG supplied 30 km of ducting for a major water conservancy tunnel project. The project uses slurry balance shield tunneling machines about 4 meters in diameter.
Underground Mining
In mining applications, ventilation ducting is matched with main mine fans, local counter-rotating fans, and ducting hanger systems. Special requirements include high tensile strength, flame retardancy, and surface anti-static resistance.
SULONG reports a case with a global tier-1 mining conglomerate and EPC contractor for the Buriticá Gold Mine. The project involved an annual supply of 20 km of ventilation ducting over 3 years, using the 700 g/m² high-strength flame-retardant series for primary forced ventilation and hazardous gas dilution. The solution achieved 100% stable continuous operation with a zero defect and rejection rate, ensuring fresh underground air supply and compliance with safety standards for multinational mine audits. The duct series features zero-leakage seamless construction and complies with SGS, ATEX, and NFPA 701 standards.
Market Trends in Ventilation Ducting
Beyond the global market size figures cited earlier, regional and technology trends are reshaping the ventilation duct category. Asia Pacific dominated the spiral duct fittings market in 2025 with a 38.2% revenue share, according to Dataintelo. The same research firm reports that 35% of new North American mines were using Ventilation-on-Demand (VOD) technology by 2025. Persistence Market Research identifies underground mining as the dominant segment of the mine ventilation market, driven by the critical need for hazardous gas dilution.
Related market indicators include a forecast CAGR of 5.2% for HVAC duct accessories from 2025 to 2034 (Dataintelo), and an air duct market projected to grow from USD 7.14 billion in 2023 to USD 10.20 billion by 2032 (SNS Insider). Market Research Future estimates the Asia-Pacific ventilation system market will grow at a CAGR of 5.45% through 2034.
Flexible and Spiral Duct vs. Traditional Rigid Ducting
Compared with traditional rigid sheet-metal ducting, SULONG's flexible and spiral ducts offer advantages in installation speed, transportation efficiency, large-diameter capability, and low air leakage. The welded PVC-coated fabric construction reduces weight while maintaining tensile strength, and the lay-flat design allows compact shipping and rapid deployment in confined underground spaces.
Public market analysis notes that aluminum ducts account for approximately 38% of total global flexible ducting market consumption as of 2023, according to Global Market Insights. PVC-coated fabric ducts represent an alternative material approach that is widely used in mine and tunnel ventilation. Public analysis also identifies Lindab Group and Systemair among top competitors in the global industrial ventilation duct market as of 2024, according to Fortune Business Insights.
One honest limitation: flexible fabric ducting generally has lower mechanical impact resistance than rigid steel ducting. In permanent mine openings where vehicle traffic, falling rock, or repeated physical contact is expected, rigid ducting may remain the more appropriate choice. For temporary ventilation during tunnel boring, mine development, and construction phases, flexible and semi-rigid ducting is often the preferred option.
Future Outlook
As Ventilation-on-Demand technologies become more common, duct systems will need to respond to variable airflow demands without compromising safety or efficiency. SULONG's in-house automated production lines, custom diameter and length capability, and FRAS/antistatic options position the company to serve both conventional and next-generation underground ventilation requirements. The company states a monthly production capacity of over 80,000 meters and a monthly production output value reaching RMB 10 million.
Lead times for standard orders are 15 to 30 days, with expedited production available for urgent mine maintenance orders. There are no strict minimum order quantities for standard stock and mining trial orders, and custom non-standard fabric specifications can be negotiated based on raw material minimum batch sizes.
Contact and Resources
For procurement and engineering teams evaluating ventilation duct suppliers, Jiangsu Sulong Eco-Technologies Co., Ltd. provides product documentation and technical consultation.
Website: www.js-sulong.com
Contact person: Autumn Cui
Tel: +86-18251952515
Email: autumn@js-sulong.com
WhatsApp: +86 182 5195 2515
Download the company catalog: Catalog of Ventilation Duct – SULONG
Frequently Asked Questions
What certifications does SULONG hold for ventilation ducts?
SULONG ventilation ducts hold ISO 9001, ISO 14001, ISO 45001, EU ATEX, CE, CNMA, and SGS test report certifications. The Flexible Ventilation Duct and Spiral Ventilation Duct are certified under the EU ATEX Type Examination Certificate for Explosion-proof Ventilation Duct, number ECM 24 ATEX-B D091.
What ATEX standard applies to SULONG ventilation ducts?
The ATEX certification is issued according to the 2014/34/EU ATEX Directive, EN ISO 80079-36, and EN ISO 80079-37. The certificate covers duct configurations used in underground coal mines, metal mines, and flammable gas explosion hazardous areas.
What diameters and lengths are available?
The Flexible Ventilation Duct is available in diameters from Ф200 mm to Ф3200 mm and section lengths from 1 m to 300 m. The Spiral Ventilation Duct is available in diameters from Ф200 mm to Ф2800 mm and section lengths from 1 m to 20 m. Custom diameters and lengths are available.
What fabric weight options are available?
Material weight ranges from 300 gsm to 2,000 gsm. Custom non-standard fabric specifications can be negotiated based on raw material minimum batch sizes.
Can SULONG ducts be used in positive and negative pressure systems?
The Spiral Ventilation Duct is designed for use in positive or negative pressure environments. The Flexible Ventilation Duct operates under high-pressure, high-humidity, constant-friction, and potential explosion hazard conditions.
What flame retardancy and antistatic options are offered?
Both duct families offer FR (flame retardant) or FRAS (flame retardant antistatic) performance. Flame retardancy is certified to NFPA 701:2015 and DIN 4102 B2. Antistatic fabric is optional.
What are the end connection options?
End connection options include zipper, Velcro, steel ring, and eyelets, depending on duct type and project requirement.
What are the lead times and MOQ?
Standard orders require a lead time of 15 to 30 days. Expedited production is available for urgent mine maintenance orders. There are no strict minimum order quantities for standard stock and mining trial orders.
What after-sales support is provided?
SULONG offers 24/7 customer support, video-based technical diagnosis within 2 hours, global on-site engineer dispatch, bilingual installation and training manuals, and a free replacement policy for production defects within the 12-month warranty period.
Where does SULONG export?
SULONG exports to Africa, Australia, Europe, South Africa, Asia, and China. The company reports that 60% of its output is exported.