4-72 Series Centrifugal Fan - Explosion-proof & Corrosion-resistant with High-Efficiency Impeller for Industrial Ventilation

The 4-72 series centrifugal fan is the earliest and most widely used industrial ventilation equipment in China, available in three specialized versions to meet diverse application needs:

• Standard 4-72: For general indoor ventilation and air exchange in factories and large buildings, conveying non-flammable, non-toxic, non-corrosive gases
• B4-72 Explosion-proof: Designed for conveying flammable and volatile gases
• F4-72 Corrosion-resistant: Manufactured with stainless steel, FRP or other corrosion-resistant materials for handling corrosive gases

All versions are engineered to convey gases with no viscous substances, dust and hard particle content ≤150 mg/m³, and maximum gas temperature ≤80℃. This versatile fan series is found in applications ranging from high-rise buildings and subway systems to boiler blowers and factory ventilation across all regions.

• Equipped with 10 backward-curved airfoil-shaped blades welded between a curved wheel cover and flat back disk
• Standard impellers made of high-quality steel plates; B4-72 impellers use cast aluminum alloy for explosion protection
• All impellers undergo strict static and dynamic balancing correction as well as overspeed operation tests
• Delivers high efficiency, smooth and reliable operation with excellent aerodynamic performance

• Volute-shaped casing with robust structural strength
• Integrated non-detachable casing for models No.2.8~12 for compact installation
• Three-part split casing for models No.16~20 (divided horizontally and vertically), allowing easy insertion/removal of the impeller during installation and maintenance

• Integral structure with a curved axial cross-section
• Ensures smooth airflow entry into the impeller with minimal pressure loss

• Type A (Direct Drive): For models No.2.8~5, impeller and casing directly mounted on motor shaft
• Type C (Belt Drive): For models No.6~12, pulleys located outside bearings for easy speed adjustment
• Type D (Coupling Drive): For models No.8~12, rigid coupling connection for high transmission efficiency
• Type B (Belt Drive): For models No.16~20, pulleys positioned between bearings for stable operation of large fans

• Main shaft made of high-quality steel for long service life
• Complete transmission system includes bearing housing, rolling bearings, pulleys or couplings as appropriate

Note: Parameters are based on standard conditions (air temperature 20℃, atmospheric pressure 101325Pa, air density 1.2kg/m³). Performance conversion is required for non-standard working conditions.

• Rotation Direction: Right-hand (clockwise when viewed from motor end) / Left-hand (counterclockwise when viewed from motor end)
• Air Outlet Angle:
  • No.2.8: 0°~225° adjustable in 45° increments
  • No.3.2~6: 0°~225° adjustable in 22.5° increments
  • No.8~12: 0°~225° adjustable in 45° increments
  • No.16~20: Fixed at 0°, 90°, 180° (must be specified when ordering)
• Material Versions: Standard steel (4-72), Explosion-proof aluminum alloy (B4-72), Corrosion-resistant stainless steel/FRP (F4-72)

• Standard 4-72: General factory ventilation, large building HVAC systems, warehouse air circulation, boiler air supply, workshop exhaust
• B4-72 Explosion-proof: Chemical plants, oil refineries, gas stations, paint shops, mines and other environments with flammable/explosive gases
• F4-72 Corrosion-resistant: Electroplating factories, chemical processing plants, wastewater treatment facilities, acid/alkali gas exhaust systems

• Type A Drive: 1* fan unit, 1* matching motor, 1 set of anchor bolts
• Type B/C Drive: 1* fan unit, 1* matching motor, 1 set of motor slide rails, 1 set of anchor bolts, 1* motor pulley, 1 set of V-belts
• Type D Drive: 1* fan unit, 1* matching motor, 1 set of anchor bolts, 1 set of coupling
• Customized supply scope available according to customer agreements

When placing an order, please clearly specify the following information:

1. Fan model number (No.) and version (4-72/B4-72/F4-72)
2. Required air flow (m³/h) and full pressure (Pa)
3. Air outlet angle and rotation direction
4. Motor model, rated power (kW) and rated speed (r/min)
5. Any special requirements for materials, coatings or accessories

If the standard model, transmission method or outlet angle does not meet your production needs, our factory can provide customized modification and design services to your satisfaction.

Established in 1999, Hunan Xinhongyuan Hi-Tech Co., Ltd. illuminates the industrial landscape with its pioneering spirit and profound expertise in industrial blowers and centrifugal fan equipment. As a distinguished national high-tech enterprise, we masterfully navigate the entire spectrum of research and development, production, sales, and service. Our extensive product range spans axial fans, centrifugal fans, and silent fans, all supported by a seamless and integrated customer service system that fuses R&D, production, and sales into a harmonious whole.

Driven by an unwavering commitment to technological advancement, we embody the 'brand enterprise' philosophy. Our collaborative ventures with illustrious institutions, including Central South University, Zhejiang University, Huazhong University of Science and Technology, and Changsha University of Science and Technology, foster ongoing technical exchange and cooperation. Together, we are empowered to continually push the frontiers of fluid dynamics and engineering excellence.

Our steadfast dedication to groundbreaking independent research and development has led to the formation of a top-tier R&D team. By employing state-of-the-art technologies such as 3D modeling, CFD flow field simulation, FEA finite element analysis, and CAD computer-aided design, we consistently redefine the parameters of fan technology. By seamlessly integrating these cutting-edge methodologies with our vast practical expertise, we persistently innovate and elevate our product offerings, establishing new standards for performance and efficiency in the industry.

We have advanced technology, high-quality products, a complete after-sales service system, and rich industry experience. In terms of technology, we continue to innovate and continuously introduce products with better performance; in terms of product quality, we strictly control every link to ensure the reliability and stability of the products; in terms of after-sales service, we respond promptly and comprehensively protect the rights and interests of customers; our rich project experience enables us to quickly and accurately meet the diverse needs of different customers, and has established a good reputation in the industry.

We offer fan-related products, as well as customized solutions on demand, and are always available for consulting services.

Our team members are professionals in the wind turbine application industry, the company was established for 30 years, focusing on product research and development, and has rich experience in manufacturing process and production management.