Explore our certified explosion-proof and high-performance AC motors designed for petrochemical, mining, and industrial process requirements.
In explosive hazard environments where combustible gases, vapors, or mists are continuously or intermittently present, safety standards demand uncompromising containment. An Ex D Motor (technically defined under the global standard IEC/EN 60079-1) employs a "flameproof" methodology.
Unlike types of protection that prevent hot spots or sparks from occurring (Ex e or Ex n), an Ex D motor is specifically designed to withstand an internal explosion of a flammable mixture. Should explosive gases penetrate the enclosure and ignite, the heavy-duty enclosure contains the pressure. Furthermore, the escape path (the flamepath gap) is carefully calculated to cool the escaping hot combustion gases below the ignition temperature of the surrounding atmosphere.
The global demand for high-efficiency flameproof motors is undergoing a significant transformation driven by energy policies and digital transition parameters. The integration of IE4 and IE5 efficiency levels into explosion-proof platforms has moved from a premium custom choice to a baseline operational requirement.
Moreover, the modern deployment of Variable Frequency Drives (VFDs) requires special consideration for Ex D motors, especially regarding stator voltage insulation spikes (dV/dt) and high-frequency bearing currents. Global industrial systems demand robust solutions that combine explosion protection with smart diagnostics, enabling remote status monitoring within Zone 1 and Zone 2 hazardous areas without compromising local containment integrity.
Shaanxi Nanfang Motor Technology Co., Ltd serves as the authorized distributor of Wolong, delivering premier industrial solutions to international markets. Wolong Electric Drive Group Co., Ltd was established in 1984 and listed on the Shanghai Stock Exchange in 2002 (code SH600580). Over more than three decades of strategic expansion, Wolong has solidified its role as a premier powerhouse in electric motor manufacturing, boasting 3 manufacturing bases, 39 factories, and 4 dedicated R&D centers worldwide.
Focusing continuously on the research, manufacture, and deployment of electric motors and advanced electronic control systems, Wolong executes a global brand strategy. This long-term commitment translates to a dominant presence in technology, global process consistency, high-redundancy manufacturing, and responsive local services across international trade corridors.
Combining regulatory conformity with modern efficiency to solve demanding industrial system tasks.
We provide full compliance models for hazardous zone applications worldwide. Our motors carry certifications including ATEX, IECEx, EAC (CU-TR), SABS, and TestSafe to ensure quick local commissioning.
Transition your facilities to IE3, IE4, or IE5 premium efficiency classes. Wolong provides standard induction and advanced permanent magnet synchronous motor (PMSM) systems to optimize energy expenditure.
Our catalog covers low-voltage, medium-voltage, and high-voltage three-phase asynchronous motors designed for pumps, ventilation, compressors, and high-shock operations across heavy industry.
Strategic acquisitions that unify historical craftsmanship with modern electrical design technologies.
Wolong has established motor and drive control R&D centers in China, Europe, and Japan, complemented by a Central Research Institute in Shanghai. Through these resources, the group researches technology innovations in material science, magnetic design, and high-integrity explosion-proof structures, securing a leading position in industrial electrical drives.
By integrating domestic expertise with historic international manufacturers, Wolong offers a broad portfolio. The brand family includes Nanyang Explosion, Brook Crompton, Morley, Laurence Scott, Schorch, ATB, and OLI. This combined legacy supports specialized configurations across oil and gas, petrochemicals, energy, and mining operations.
Acquired in 2011. ATB is one of Europe's premier motor manufacturers, providing bespoke, highly specialized motor solutions for core processing plants.
With nearly 130 years of history, Morley specializes in heavy-duty underground coal mining motors, recognized globally for mechanical durability.
Renowned for low starting current systems, Laurence Scott historically supplied generators and motors to nuclear power facilities and naval defense forces.
An established participant with over a century of design expertise, leading energy-efficient developments with its "W" and "10" series for harsh environments.
Established in 1882, Schorch delivers heavy-duty custom driving systems for global oil, gas, chemical, water treatment, and steel projects.
A global manufacturer of industrial vibration motors (MVE) and sensors. Wolong initiated this joint venture in China in 1999.
Joined Wolong in 2015. CNE operates as a large explosion-proof motor research and manufacturing base in China, focusing on hazardous process protection.
Partnered with Wolong in 2018 for commercial and industrial motors. The cooperation supports heavy industry sectors like metallurgy, pulp, and materials processing.
Acquiring historical expertise has allowed Wolong to expand its industrial capabilities. The 2011 acquisition of 97.94% of the Austrian ATB Group brought key technology portfolios under its management, including the Morley mining brand and Laurence Scott.
Morley motors are engineered for underground mining equipment, where machinery must withstand high shocks and wet, explosive environments. Laurence Scott specializes in systems with low starting currents, which protect delicate electrical grids in nuclear plants and marine vessels from high-impact voltage drops.
Similarly, Brook Crompton brought over a century of motor design experience, contributing to Wolong’s development of efficient high-, medium-, and low-voltage motors. Schorch continues to serve heavy-duty industrial sectors with large-capacity motors, while the addition of GE Industrial Motors in 2018 helped expand the group's global support capabilities.
Additionally, Wolong’s partnership with OLI Vibration Motors has expanded its vibration technology line. In the explosion-proof motor sector, the integration of Nanyang Explosion-proof Group (CNE) in 2015 brought together two of the field's major research and production entities. This unified strategy supports a complete manufacturing flow from raw materials and winding insulation to automated final testing.
Inside the high-redundancy structural design of Wolong Ex D Explosion-Proof Motors.
Our rotors feature a robust squirrel-cage design. Cast aluminum rotors are produced using centrifugal casting or high-pressure die-casting, forming a single-piece construction where the rotor bars and end rings are integrated directly into the rotor core slots. This process helps minimize internal voids and delivers consistent starting torque. For larger-capacity machines, copper bar rotors are used, with structural bars secured and end rings welded to handle thermal expansion. The high-speed rotor design also incorporates a protective retaining ring system to ensure stability during dynamic operations.
The stator coil is insulated with polyester film reinforced with glass cloth and high-mica content tape. Following winding, the stator undergo a Vacuum Pressure Impregnation (VPI) process. This process removes air pockets and fully coats the core with epoxy resin. The cured insulation provides protection against moisture, chemical exposure, and thermal cycling, helping extend the operating life of the motor in harsh industrial conditions.
Motor frames are designed using digital multi-physics simulation platforms to model structural stress and thermal dissipation. Cast in high-strength grey iron or fabricated from structural steel, the frames are built with wall thickness margins to contain potential internal gas explosions without outer deformation. Optimized cooling fins help dissipate heat, maintaining lower operating temperatures and protecting bearing systems from thermal stress.
The low-noise ventilation system consists of an engineered fan cover, an internal air guide cylinder, protective entry windows, and sound-absorbing silencer plates. Air is drawn from the sides to minimize turbulence and energy loss along the propagation path. Built-in sound-attenuating linings help absorb high-frequency noise. The system is rated to IP22 protection standards, keeping personnel clear of rotating fan blades while maintaining cooling airflow.
Ensuring compliance with major international safety standards for explosive atmospheres.
Nemko / ATEX
CSA
CE Compliance
CCC Ex
SABS (South Africa)
TESTSAFE (Australia)
Wolong maintains a global certification structure to support export operations and international trade requirements:
Providing drive systems for critical machinery in hazardous and heavy industrial applications.
Wolong provides drive and motor solutions across 39 manufacturing plants and 4 research centers globally. Our Ex D flameproof and heavy-duty industrial motors are configured for standard and custom machinery, including fans, water pumps, compressors, and material handling systems.
We supply drive components to fields such as ventilation, refrigeration, petrochemical processing, coal chemical operations, metallurgy, nuclear power, and marine automation. Our engineering focus is on maintaining system reliability, safety, and energy efficiency for global projects.
The next generation of flameproof drive systems: Decarbonization, Integration, and Intelligence.
We are expanding our range of PM synchronous motors to IE5 efficiency levels, adapting permanent magnet technology for explosion-proof designs to reduce operating losses under continuous duty cycles.
Future Ex D systems are designed to support built-in, intrinsically safe monitoring sensors. These sensors track vibration, temperature, and current in real time, feeding data to control platforms without compromising the physical flamepath.
We focus on refining the electrical design to improve power factor values and reduce motor temperature rise. These optimizations help extend bearing grease service life and lower overall maintenance costs.
Technical answers for engineers, procurement officers, and plant operators.
High-voltage asynchronous motors, positive pressure systems, and heavy-conveyor drive systems.
NANFANG