Dongqi 10t HD Explosion-Proof Crane 9m Lift Varnish Workshop Sale South Africa

The HD model explosion-proof single girder overhead crane from Dongqi Crane is a lifting system engineered for a single, uncompromising requirement: operate safely where a spark is not an inconvenience but an ignition source. The crane works in flammable, explosive and corrosive media environments, and is widely deployed in factories, warehouses, and material yards across military, chemical, coal washing, and pharmaceutical operations.

The HD platform combines Dongqi’s European-spec lightweight single girder architecture with a full explosion-proof electrical and mechanical package, designed to FEM and GB production standards. Every motor, control panel, limit switch, brake, and wiring element in the lifting and travel systems is selected or enclosed to prevent ignition of the surrounding atmosphere—not merely protected against dust and moisture.

The result is not a standard crane with an “explosion-proof” label applied to the hoist. It is a coordinated Ex-rated system in which the structure, coatings, wheels, hook, electrical enclosures, and control logic are matched to the hazardous zone classification of the workplace.

Explosion Protection: What “Explosion-Proof” Means on This Crane

Explosion protection on an overhead crane operates through containment and prevention, not through detection alone. The HD model applies both principles:

Flameproof enclosure (Ex d). Electrical components that could produce a spark or arc—motors, control panels, junction boxes—are housed in enclosures designed to contain an internal explosion and quench the flame before it can escape into the surrounding atmosphere. The enclosure joints are engineered to cool escaping gases below ignition temperature.

Increased safety (Ex e). Terminal boxes, wiring, and connection points are designed with enhanced insulation, clearance, and protection to eliminate the likelihood of sparking or excessive temperature under normal operation and specified fault conditions.

Non-sparking mechanical contact. Crane wheels are produced in stainless steel or nylon to avoid frictional sparking at the runway interface. Hooks and other exposed contact components are supplied in anti-sparking materials to prevent mechanical ignition during load engagement or impact.

Explosion-proof grades and zone suitability

The HD explosion-proof single girder crane is available in the following classifications:

Temperature class T4 corresponds to a maximum surface temperature of 135°C, suitable for atmospheres with ignition temperatures not lower than T4. Dongqi confirms the final grade against the client’s hazardous area classification drawing; the crane is not selected on capacity alone.

Technical Specifications

Working class note. A3/A4 reflects the duty expected in hazardous-area maintenance, batch handling, and intermittent production environments. For continuous or heavy-cycling hazardous duty, Dongqi reviews the hoist group, motor temperature rise, and duty classification together; explosion-proof motors are typically supplied with Class F insulation and Class B temperature rise to maintain thermal margin under Ex enclosure conditions.

Design and Construction

Hoisting and travel: BNR explosion-proof hoist platform

The HD crane uses the BNR-type explosion-proof electric hoist as its lifting mechanism. The BNR platform is designed for flammable and explosive industrial environments, with a compact, low-headroom structure that preserves hook height under the girder. Key mechanical design points include:

• Explosion-proof shell design that contains potential internal explosions and prevents flame escape.

• Key components in spark-resistant materials, including motor parts, wiring, and switches, to reduce ignition risk on contact.

• Sealing structure that blocks the ingress of flammable gases, vapours, or dust into electrical and mechanical enclosures.

• Modular arrangement, allowing the hoist to be configured for single girder low-headroom mounting while keeping the explosion-proof boundary intact.

The crane travels on a single box-type girder. Crane wheels are stainless steel or nylon, and end carriage components are selected to avoid frictional sparking at the runway interface.

Surface protection: epoxy zinc-rich primer + chlorinated rubber topcoat

Hazardous environments are frequently corrosive as well as explosive—chemical plants, coal washing facilities, and pharmaceutical units expose the crane structure to moisture, acidic vapours, and process dust. The HD explosion-proof crane is coated with an epoxy zinc-rich primer for cathodic protection at the steel surface, followed by a chlorinated rubber topcoat that provides a chemically resistant barrier against corrosive media. This coating system is part of the crane’s fitness for the combined explosive + corrosive service condition, not an aesthetic finish.

VFD and motion control

Frequency conversion is available for lifting, cross travelling, and crane travelling, providing soft start/stop, reduced load swing, and stable operation. In explosion-proof applications, VFD control also allows lower mechanical shock at start and stop, reducing wear on brake components and travel wheels—both of which are ignition-relevant interfaces in a hazardous zone. Hoisting may be configured with dual-speed pole-changing control where VFD is not specified, with inverter control recommended for trolley and bridge motions for smooth, precise positioning.

Safety and Protection

The HD explosion-proof crane is supplied with a protection set configured to the working conditions and the explosion-proof boundary:

• Overload limiter — prevents lifting beyond rated capacity, with warning horn.

• Lifting height limiter — limits upper and lower hook travel.

• Cross-travelling limiter — limits trolley motion at extremities.

• Crane long-travel limiter — limits bridge travel at runway ends.

• Automatic power-off protection — isolates power on fault or emergency stop.

• Explosion-proof electrical enclosures — IP55 minimum, IP65 available, matching the zone classification.

• Non-sparking wheels and hook — stainless steel / nylon wheels; anti-sparking hook material.

• Asbestos-free brake lining — brake activates automatically on power failure.

• Buffer devices — protect trolley and bridge travel extremities; surface resistance of buffer materials controlled within specified limits.

• Warning indicators — anti-collision devices, flashing lights, and audible alarms as configured.

Optional crane black box with recorded analysis functions is available on request, providing operating data capture for hazardous-area maintenance planning and incident review. Customized overhead crane solutions are available for special industries where the standard configuration does not cover the zone, gas group, or corrosion profile.

Control Options

The HD explosion-proof crane supports multiple control configurations to suit operator positioning and zone requirements:

• Pendant control — suspended station for ground-level operation, with explosion-proof enclosure and IP-rated handle.

• Remote control — wireless operation for flexible positioning, with Ex-rated transmitter where required by the zone.

• Cabin control — available for larger spans or where an operator station is preferred, with the cabin and its electricals integrated into the explosion-protection scheme.

All control interfaces are selected or enclosed to maintain the crane’s explosion-proof integrity; the control method does not create an unprotected ignition path into the hazardous area.

Applications

The HD explosion-proof single girder overhead crane is specified where flammable gases, vapours, combustible dusts, or corrosive media are present in the working atmosphere. Typical environments include:

• Chemical plants — handling of raw materials, intermediates, and finished products in solvent, gas, and corrosive service.

• Pharmaceutical units — lifting in solvent-handling, synthesis, and material transfer areas where flammable vapours may be present.

• Coal washing plants and coal handling facilities — lifting coal, coke, and mining equipment in dust-classified areas.

• Military and explosive-material facilities — where ignition prevention is a mission-critical requirement.

• Paint shops, oil refineries, gas power plants, and wastewater treatment plants — Dongqi’s explosion-proof range is applied across these hazardous industrial environments.

• Warehouses and material yards storing or handling flammable or explosive goods.

• Maintenance shops and workshops supporting hazardous-process equipment.

The HD model is particularly appropriate for facilities that need European-spec single girder economy and low headroom without compromising the explosion-protection boundary—in other words, where a standard crane cannot be installed but a heavy double girder Ex crane would be over-specified for the duty.

Selection Guidance

Dongqi reviews the hazardous area classification, gas/dust group, temperature class, corrosion profile, and duty cycle together rather than quoting a crane on capacity and span alone. The explosion-proof grade is confirmed against the client’s zone drawing before manufacture.

Manufacturer: Dongqi Crane

Dongqi Crane designs and manufactures the HD explosion-proof single girder overhead crane as a FEM/GB-based Ex-rated lifting system, integrating the single girder structure, explosion-proof BNR hoist, non-sparking travel components, Ex electrical package, and corrosion-resistant coating as a matched hazardous-area solution. The explosion-proof crane range is applied across chemical, gas power, paint, refinery, coal, and pharmaceutical environments, with customized configurations available for special industries whose zone or process conditions fall outside the standard catalogue.

Request a Configuration

To receive a matched HD explosion-proof crane proposal from Dongqi Crane, please provide:

1. Capacity required (t, up to 20 t)

2. Span (m, centre-to-centre of runway rails)

3. Lifting height (m, hook travel required)

4. Hazardous area classification — Zone (0/1/2 or 20/21/22), gas/dust group (IIA/IIB/IIC), temperature class (T1–T4 or higher)

5. Corrosive media present (chemical type, concentration, humidity, washdown)

6. Working environment (indoor/outdoor, ambient temperature, ventilation)

7. Duty cycle (hours per day, shifts, load spectrum)

8. Control preference (pendant, remote, cabin)

9. Any special industry requirement requiring a customized Ex solution