Dongqi 20t QDX Explosion-Proof Crane 15m Lift Refinery Sale Spain

The QDX model explosion-proof double girder overhead crane from Dongqi Crane is built on the proven QDX European-spec double girder platform, with all motors and electrical components adopting explosion-proof measures for service in flammable and explosive locations. It is designed for explosion-proof levels IIB, IIC, and dust environments, making it suitable for the hazardous-area lifting requirements of military, chemical, coal washing, pharmaceutical, and other process industries.

Explosion-proof overhead cranes work in environments where flammable, explosive, and corrosive media are present. They are widely used in factories, warehouses, material yards, and similar facilities where ignition prevention is a continuous operational requirement, not an occasional precaution. The QDX explosion-proof configuration addresses this by combining a heavy-duty double girder structure with an Ex-rated drive and control package, so the crane can deliver the capacity and stability of a European-spec double girder machine without introducing an ignition source into the classified area.

The crane is manufactured to FEM and GB production standards, with a coating system of epoxy zinc-rich primer and chlorinated rubber topcoat for corrosion resistance in chemically aggressive atmospheres.

Explosion Protection: How the QDX Is Made Ex-Rated

Explosion protection on this crane is a system-level design decision, not a label applied to the hoist alone. The QDX Ex configuration applies containment and prevention across the structural, mechanical, and electrical systems.

Flameproof enclosure (Ex d). Motors, brakes, control panels, and junction boxes that could produce a spark or arc are enclosed in housings designed to contain an internal explosion and quench the flame before it reaches the surrounding atmosphere. Explosion-proof motors and electrical components are selected and enclosed to maintain this boundary across the full duty cycle.

Increased safety (Ex e). Wiring, terminals, and connection points are designed with enhanced insulation, clearance, and protection to eliminate sparking and excessive temperature under normal operation and specified fault conditions.

Non-sparking mechanical interfaces. Crane wheels are supplied in stainless steel or nylon to prevent frictional sparking at the runway contact. Buffer materials and hook contact surfaces are selected to avoid mechanical ignition during load engagement or end-of-travel impact.

Explosion-proof grades and zone suitability

The QDX explosion-proof crane is available to suit the following hazardous-area classifications:

Temperature class T4 corresponds to a maximum surface temperature of 135°C, suitable for atmospheres whose ignition temperature is not lower than T4. Electrical enclosures are supplied to a minimum of IP55, with higher IP ratings available on request. Dongqi confirms the final grade against the client‘s hazardous area classification drawing before manufacture; the crane is not selected on capacity and span alone.

Technical Specifications

Capacity note. The standard explosion-proof double girder range is commonly supplied in the 5–75 t band with A4/A5 working class. The QDX platform itself extends to much higher capacities; applications approaching 300 t are reviewed individually for wheel load, explosion-proof boundary integrity, and runway support capacity before quotation.

Design and Construction

QDX double girder platform

The QDX is a European-spec double girder crane designed to FEM standards, with box-type welded main girders and a tight structure and light dead weight relative to conventional double girder machines. The twin-girder configuration places the hoist trolley between the girders, distributing load across two beams and supporting stable travel and positioning under heavy capacity.

Coating system: 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 structure to moisture, acidic vapours, and process dust. The QDX 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 selected for the combined explosive + corrosive service condition, not as a decorative finish.

Electrical and drive

All motors and electrical parts adopt explosion-proof measures. Electrical components are selected and enclosed to maintain the Ex boundary, with minimum IP55 protection and thermal protection for pole-changing and inverter drive configurations. The crane is available with frequency conversion for lifting, cross travelling, and crane travelling, providing soft start/stop, reduced load swing, and lower mechanical shock at brake and wheel interfaces.

Safety and Protection

The QDX explosion-proof crane is supplied with a comprehensive protection set matched to hazardous-area service:

• Overload limiter — prevents lifting beyond rated capacity.

• 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, maintaining the Ex boundary.

• Non-sparking wheels — stainless steel or nylon, preventing frictional ignition at the runway interface.

• Warning indicators — audible and visual alarms as configured.

Customized overhead crane solutions are available for special industries where the standard Ex configuration does not fully cover the zone, gas group, dust type, or corrosion profile.

Control Options

The QDX 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 an Ex-rated transmitter where the zone requires it.

• 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 QDX explosion-proof double girder crane is specified where flammable gases, vapours, combustible dusts, or corrosive media are present and the lifting duty requires the capacity and stability of a double girder machine. Typical environments include:

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

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

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

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

• Oil refineries, paint industries, 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.

The QDX Ex model is particularly appropriate for facilities that need double girder capacity and span but cannot compromise the explosion-protection boundary—where a single girder Ex crane would be capacity- or span-limited, and a standard double girder crane cannot be installed.

Selection Guidance

Dongqi reviews the hazardous area classification, gas/dust group, temperature class, corrosion profile, duty cycle, and capacity together rather than quoting a crane on tonnage 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 QDX explosion-proof double girder overhead crane as a FEM/GB-based Ex-rated lifting system, integrating the QDX European-spec double girder structure, explosion-proof motors and electrics, non-sparking travel components, and corrosion-resistant coating as a matched hazardous-area solution. Dongqi supports configuration review, hazardous-area interface checking, and customized configurations for special industries whose zone or process conditions fall outside the standard catalogue.

Request a Configuration

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

1. Capacity required (t, standard Ex range 5–75 t; higher capacities reviewed to 300 t)

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

3. Lifting height (m, hook travel required)

4. Hazardous area classification — Zone (1/2 or 21/22), gas/dust group (IIB/IIC or dust type), 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