Product Features

Design Philosophy 

• Fully considering comprehensive benefits, the crane minimizes the overall height, simplifies the structure, reduces deadweight and wheel load, thereby lowering the overall building height, allowing for lighter building structures, and reducing crane operating costs.
• The crane design fully considers improvements in electrical drive and control. It combines automation technology with mechanical transmission technology, applying advanced microelectronics, power electronics, and fuzzy control technology to the drive and control systems of the machinery, achieving automation and semi-automation.
• Optimizes crane mechanisms, improves product appearance, simplifies mechanisms, and enhances manufacturing processes. This results in crane products with novel structures, reasonable layouts, high transmission efficiency, stability, durability, and ease of processing, thereby improving production efficiency.

Applications

Weihua is a professional overhead crane manufacturer, providing one-stop customized solutions for QD double-girder overhead cranes with hooks. Whether it’s customized design for specific working conditions or lifting equipment meeting high safety standards, we can tailor solutions based on actual working conditions and on-site requirements. Free customized lifting solutions are available.

Lifting Hook Type Options

Overhead crane hooks can be divided into 4 types based on structure, application, and industry standards. When customizing a hook crane, please select the appropriate hook according to requirements. Below are the features and applications of each hook type:

• 1. General Purpose Hook (Specification: 3.2t-88t)

          Standard single hook block design, simple structure, low manufacturing cost, complies with DIN/ISO standards, safety factor ≥4 times. Suitable for a wide range of daily lifting operations, covering a broad load range (0.5~300 tons). Optional forged or laminated structure for high durability. Widely used in daily material handling such as factory warehouses, construction sites (hoisting rebar, precast components), and bulk cargo loading/unloading at port logistics centers.

• 2. Swivel Hook (Specification: 10t-400t)

        Built-in precision bearings allow 360°自由 rotation, preventing wire rope twisting. Utilizes double-row angular contact bearings with strong axial and radial load capacity. Some models are equipped with servo control for precise positioning (±0.5°), suitable for high-precision lifting or anti-rotation requirements for long materials. Widely used in shipbuilding (steel plate, pipe lifting), wind power (blade installation), automated production lines (requiring precise alignment), etc.

• 3. New Type Hook (Specification: 5t-600t)

        Made of high-strength alloy steel with optimized structural design, weight reduced by 15%~20% while maintaining strength. Complies with the latest FEM/ISO standards with higher safety factors. Widely used in high-end manufacturing (aerospace, automotive assembly), intelligent warehousing and logistics (automated lifting systems), heavy machinery (requiring high-strength, lightweight hooks), etc.

• 4. Specialized Hook (Specification: 5t-600t)

        Designed for electric/manual hoists with standardized interfaces; compact design suitable for small spaces; optional quick-release design for easy spreader更换. Widely used in light lifting in workshops (1~20 tons), maintenance work (equipment disassembly), material transfer on production lines (with hoists), etc.

Advantages & Features

Applications

•  QD overhead cranes are widely popular in numerous fields such as indoor and outdoor industrial and mining facilities, chemical industry, ferrous metallurgy, railway transport, ports and terminals, and logistics warehouses.  
•  In industrial and mining enterprise workshops, double-girder hook overhead cranes can lift raw materials, semi-finished products, and finished products. This greatly facilitates the efficient operation of the production process.
• For steel and chemical plants, it can move heavy equipment, steel, and chemical raw materials.
• In railway transport, it can assist in loading and unloading goods. At ports and terminals, it is a powerful tool for loading, unloading, hoisting, and transporting containers and bulk cargo. In logistics warehouses, it can efficiently handle the storage and transfer of various types of goods.

Main Functions

• Waste Grabbing and Handling: The grab bridge crane is equipped with a hydraulic or electric grab, enabling it to effectively grab loose materials such as waste, scrap metal, and waste plastic.

• Sorting and Stacking: Used in waste sorting lines, potentially equipped with magnetic separators or manual sorting stations, to separate recyclables from waste. Feeding and Landfill: In incineration plants or landfills, waste is fed into processing equipment or compacted in layers for landfill.

Advantages & Features

Working Principle

       The QZ Grab Bridge Crane is a type of overhead crane specifically designed for handling bulk materials. Its core function is to grab, lift, transport, and discharge materials using an electrically or mechanically driven grab. Its working principle can be broken down into the following key stages:

Structural Components

The grab crane mainly consists of the bridge, electric trolley, electrical equipment, and the grab itself. The bridge provides a stable support structure for the entire crane, bearing the weight of each component and the load during lifting.

• Bridge: Spans the working area, allowing the trolley to travel horizontally along the rails.
• Hoisting Trolley: The trolley travels along the bridge for horizontal movement and is equipped with a hoisting mechanism and a closing mechanism.
• Grab: Typically adopts a double-shell or multi-shell clamshell structure. Its opening and closing are controlled by wire ropes or chains, suitable for bulk materials like coal, ore, grain, etc.

Working Process

• Grabbing Material: The grab is lowered onto the material pile via the closing mechanism. When closing, it relies on its own weight or hydraulic/electric drive to clamp the material.
• Lifting and Transporting: The hoisting mechanism lifts the loaded grab to the required height. The main and cross travel mechanisms coordinate to transport the material horizontally to the target location.
• Unloading: The grab opens again at the unloading point, releasing the material and completing one cycle.

Grab Selection

     Waste handling cranes can be equipped with different types of grabs based on material characteristics, such as light-duty grabs (for grain), medium-duty grabs (for coal), heavy-duty grabs (for ore), and special grabs (for waste, scrap steel, etc.). Common types of grabs include the following two:

1. Orange Peel Grab

• Structural Features: Composed of 4-6 curved jaws, resembling an “orange peel,” forming a closed space when closed.
• Suitable Materials: Scrap steel, waste, irregular bulk materials (e.g., metal scrap, construction waste).
• Advantages: Wide grabbing range, adapts to materials with complex shapes, good leakage prevention.

2. Clamshell Grab

• Structural Features: Composed of two symmetrical shells, resembling a “clamshell,” controlled by wire ropes or hydraulic cylinders for opening and closing.
• Suitable Materials: Bulk materials with good flowability such as coal, ore, gravel, grain.
• Advantages: Simple structure, easy maintenance, uniform gripping force.

Applications

       Waste handling cranes are widely used across various bulk material handling industries. With their efficient loading and unloading capabilities, they are key equipment in sectors such as ports, power generation, metallurgy, construction materials, chemicals, grain, and waste treatment. As the characteristics of materials handled differ across industries, matching grabs of the corresponding type is essential to ensure operational efficiency and safety.

       The QY insulated overhead crane consists of a robust bridge, crane travel mechanism, hoisting mechanism, electrical equipment, crane hook block, and insulation settings. For electrical insulation purposes, special insulating materials are used in the bridge sections. Insulating layers are installed between metal components to ensure current does not propagate through the bridge crane structure. The hoisting mechanism also requires insulation to guarantee safety when lifting live materials.

       Weihua utilizes efficient insulation materials and technologies, such as ceramics and glass fiber reinforced plastic, for insulating components. Alternatively, we add insulating gaskets between metal contact surfaces to ensure electrical insulation performance between parts.

Advantages & Features

Applications

• Non-ferrous metal smelting: The insulated hook bridge crane is suitable for the smelting processes of non-ferrous metals such as aluminum, magnesium, lead, and zinc.
• Electronics industry: Relevant workplaces such as semiconductor manufacturing workshops and electronic component production workshops.
• Power industry: Safely moving and installing large transformers and other electrical equipment in environments with high voltage, such as power plants and substations.
• Chemical industry: Suitable for electrolytic workshops and chemical material storage areas.
• Other industrial fields: Any location with potential electrical safety hazards, such as material handling in certain machining operations or assembly lines.

Specifications

        The lifting capacity of the electromagnetic overhead crane ranges from 5 tons to 32 tons (including the electromagnetic suction cup). The working classes are A5 and A6. The magnetic holding time ranges from 10 to 30 minutes. It is commonly used in steel plants, ports, scrap yards, and other locations requiring large-scale lifting and handling of ferromagnetic materials.

Working Principle

• Electromagnetic Adhesion Principle

When the crane’s electromagnetic lifting magnet is energized, the internal coil generates a powerful excitation current, forming a high-strength closed magnetic field circuit. This magnetic field effectively penetrates the ferromagnetic workpiece, establishing a stable magnetic adhesive connection between the workpiece and the magnet surface. The load capacity ranges from 0.8 to 1.5 tons.

• Material Lifting and Handling

The electromagnetic crane uses a frequency-controlled hoisting mechanism to lift the electromagnetic lifting magnet attached to the workpiece to a designated position, and then performs the handling operation.

• Power-off Unloading (using a dual-mode unloading system)

Active Demagnetization Mode: Achieves rapid demagnetization through reverse current pulses, enabling instantaneous unloading.

Passive Demagnetization Mode: Progressive power-off design prevents impact loads; equipped with a residual magnetism detection device to ensure complete workpiece detachment, with an optional vibration-assisted unloading module.

Features & Advantages

Applications

          The QC electromagnetic overhead crane offers advantages such as strong magnetic adhesion, efficient handling, and adaptability to harsh environments, making it an ideal choice for industries like steel, machinery, ports, and scrap recycling. Different industries can select traditional electromagnetic suction cups, electro-permanent magnetic (EPM) suction cups, or scrap-specific models according to their needs to optimize work efficiency. Below are applications across various industries:

1. Steel & Metallurgical Industry: Used for handling and stacking ingots, steel plates, structural steel (e.g., H-beams, I-beams), as well as the recovery and transport of pig iron, scrap steel, and iron chips. Also used for hoisting continuous casting billets and hot-rolled/cold-rolled coils. Designed to withstand high-temperature environments and suitable for frequent loading/unloading operations.

2. Machinery Manufacturing & Processing Industry: Used for handling large castings and forgings (e.g., machine tool bases, engine housings), positioning and installing steel beams and plates in metal fabrication workshops, and recovering scrap (e.g., machining chips, stamping waste). Suitable for indoor workshops or outdoor yards.

3. Ports, Terminals & Logistics Warehousing: Used for loading/unloading steel and metal coils onto/from ships, transferring scrap metal within container terminals, sorting and storing steel products in large warehouses; equipped with rainproof and corrosion-resistant designs (outdoor models include protective devices).

4. Scrap Metal Recycling Industry: Used for grabbing and sorting scrap steel, iron, and metal from dismantled vehicles, transporting metal waste on shredding lines; uses scrap-specific electromagnetic grabs with reinforced impact-resistant housings; suitable for irregular materials (e.g., scrap iron, metal chips).

5. Shipbuilding & Heavy Equipment Manufacturing: Used for hoisting hull steel plates, large steel structural components, assembling and moving heavy machinery parts, etc. Some models can be equipped with underwater electromagnetic suction cups for salvage operations.

6. Power & Energy Industry: Used for installing power plant boiler steel frames, pressure vessels, hoisting large metal components in nuclear power equipment, etc., requiring multiple safety devices such as emergency power-off magnetic adhesion.

The explosion-proof performance of all motors and electrical components of the QB explosion-proof bridge crane complies with GB3836.2-2000 “Electrical Apparatus for Explosive Gas Atmospheres Part 2: Flameproof Enclosure ‘d’,” and the overall performance complies with the regulations of JB/T5897-2006 “Explosion-proof bridge cranes.” It has passed inspection by a nationally designated explosion-proof product inspection authority and obtained the “Explosion-proof Certificate.” The explosion-proof markings are ExdⅡBT4 and ExdⅡCT4.

Components

• Main Girder and End Carriages: Double-girder structure, welded from high-quality steel, optional anti-corrosion coating treatment;
• Explosion-proof Electric Hoist or Lifting Mechanism: Core components comply with explosion-proof specifications, lifting capacity up to 5~100 tons or more;
• Travel Mechanism: Includes explosion-proof drive motor, explosion-proof brake, reducer;
• Electrical Control System: Explosion-proof electrical control box, cables, explosion-proof switches, explosion-proof lighting system;
• Safety System: Explosion-proof limiter, anti-collision device, load limiter, etc.

Explosion-proof Hoist Selection

Based on the actual application environment of the lifting equipment, we recommend the most suitable type of explosion-proof electric hoist to help your enterprise improve operational efficiency and maintenance convenience.

• Explosion-proof Wire Rope Electric Hoist: Uses high-strength steel wire rope, offering good stability and durability. With two-speed switching function, fast and slow modes can be switched during lifting as needed, suitable for applications requiring precise positioning and flexible lifting, such as precision equipment installation, handling easily swayed materials, etc.

• Low Headroom Explosion-proof Electric Hoist: Designed specifically for factories with limited lifting space or work areas with restricted structural height. The compact structure effectively reduces the overall machine height and improves lifting height utilization. Suitable for special environments like cleanrooms, laboratories, and underground pipeline corridors.

• New Chinese Style Explosion-proof Electric Hoist: Adopts a modular design featuring intelligent monitoring, variable frequency drive, and automatic fault diagnosis. This hoist offers advantages such as high protection等级, low noise, and long service life, widely used in heavy-duty, high-frequency operations or smart factory scenarios.

Applications

 The QB explosion-proof double-girder bridge crane, with its excellent explosion-proof performance and reliability, is an ideal solution for material handling in hazardous areas. It is widely used in various industrial environments requiring high safety levels. Below are its typical application industries and scenarios:

• Oil Refineries: Used for hoisting crude oil storage tanks and refining equipment.
• Chemical Production Workshops: Handling containers and equipment for flammable gases and chemicals.
• Natural Gas Stations and Filling Stations: Installation work for pressure vessels or pipelines.
• Pharmaceutical Industry: Used in cleanrooms where dust or organic solvents may be present.
• Military and Ammunition Warehouses: High-risk material handling environments requiring strict explosion-proof requirements.

 Explosion-proof double-girder bridge cranes can be further divided into various types based on different structural forms, usage scenarios, and control methods. Different types of explosion-proof bridge cranes can adapt to different loads, operating frequencies, and environmental risks. Weihua can customize the structure, explosion-proof等级, protection design, operation mode, etc., according to customer working conditions. Below are the classifications, features, and typical application scenarios of the main types, facilitating reasonable selection based on actual needs. Please check the following types:

Advantages & Features

Product Types

The double-hoist overhead crane can be divided into two main types based on the main girder structure: single-girder and double-girder. They have significant differences in structural design, load capacity, and application scenarios.

1. Single-Girder Double-Hoist Overhead Crane

The single-girder double-hoist overhead crane uses one box girder or I-beam as the main load-bearing structure, with two electric hoists (usually wire rope or chain hoists) installed on the same main girder. The load capacity is typically 5~20 tons (single hoist) or 10~32 tons (dual-hoist combined lifting), with a span range of 5~22 meters.

Advantages & Features

• Lower Cost: Simple structure, lower manufacturing and maintenance costs compared to double-girder structures.
• Light Deadweight: Suitable for situations with limited plant height or weak load-bearing capacity.
• Easy Installation: Suitable for small to medium-sized workshops or light material handling.
• High Flexibility: The two hoists can work independently or collaboratively to adapt to different working conditions.

Applications

• Light Manufacturing Industry: Such as auto parts, metal processing, small machinery assembly.
• Warehousing and Logistics: Handling packaging boxes, pallets, and light steel structural parts.
• Maintenance Workshops: Situations requiring dual lifting points, such as equipment maintenance, mold changing.

2. Double-Girder Double-Hoist Crane

The double-girder double-hoist crane utilizes two box girders or truss girders to provide greater rigidity and load capacity. It is suitable for heavy loads ranging from 20 to 500 tons or even higher (e.g., in metallurgy, shipbuilding industries). The span range is 10~35 meters, suitable for large plants. Common types include the LH double-girder overhead crane and the NLH European-type double-girder overhead crane.

Advantages & Features

• Higher Stability: Double-girder structure, better torsional resistance, suitable for precision lifting (e.g., wind turbine blade installation).
• Stronger Expandability: Magnetic spreaders, grabs, C-hooks, and other specialized spreaders can be integrated.

Applications

• Heavy Industry: Steel plants (ladle handling), shipbuilding (section lifting), mines (large equipment installation).
• Energy Industry: Wind turbines, hydraulic turbines, nuclear power pressure vessel lifting.
• Large-Scale Logistics: Port containers, heavy machinery transport.

The explosion-proof performance of all motors and electrical components of the QB type explosion-proof hook bridge crane complies with GB3836.2-2000 “Electrical apparatus for explosive gas atmospheres – Part 2: Flameproof enclosure “d”,” and the overall performance complies with the provisions of JB/T5897-2006 “Explosion-proof overhead cranes”. It has been inspected and approved by the national designated explosion-proof product inspection unit and has obtained the “Explosion-proof Certificate”. The explosion-proof markings are ExdⅡBT4 and ExdⅡCT4 respectively.

Components

• Main Girder and End Carriage: Double-girder structure, welded with high-quality steel, optional anti-corrosion coating treatment;

• Explosion-proof Electric Hoist or Hoisting Mechanism: Core components comply with explosion-proof specifications, lifting capacity from 5 to over 100 tons;

• Travel Mechanism: Includes explosion-proof drive motor, explosion-proof brake, reducer;

• Electrical Control System: Explosion-proof electrical control box, cables, explosion-proof switches, explosion-proof lighting system;

• Safety System: Explosion-proof limiter, anti-collision device, load limiter, etc. Selection of Explosion-proof Electric Hoist Type

Weihua can recommend the most suitable type of explosion-proof electric hoist based on the customer’s actual application environment, helping your enterprise improve operational efficiency and maintenance convenience.

Selection of Explosion-proof Electric Hoist Type

Weihua can recommend a suitable type of explosion-proof electric hoist based on the customer’s actual application environment, helping your enterprise improve operational efficiency and maintenance convenience.

• Explosion-proof Wire Rope Electric Hoist: Uses high-strength steel wire rope, good stability, durable, with two-speed switching function. During lifting, fast and slow modes can be switched as needed, suitable for precise positioning and flexible lifting in application scenarios with high requirements, such as precision equipment installation and handling of easily swaying materials.

• Low Headroom Explosion-proof Electric Hoist: Specifically designed for workshops with limited lifting space or work areas with restricted structural height. Compact structure effectively reduces the overall height of the machine and improves lifting height utilization. Suitable for special environments such as cleanrooms, laboratories, and underground pipeline corridors.

• New Chinese Style Explosion-proof Electric Hoist: Adopts modular design, featuring intelligent monitoring, variable frequency drive, and automatic fault diagnosis. This hoist has the advantages of high protection level, low noise, and long service life, widely used in heavy-duty, high-frequency operations or smart factory scenarios.

Features & Advantages

Applications

The QB explosion-proof overhead crane has excellent explosion-proof performance and reliability, making it an ideal solution for material handling in hazardous areas. It is widely used in various industrial environments requiring high safety levels. Below are its typical application industries and scenarios:

• Oil Refineries: Used for lifting crude oil storage tanks and refining equipment.

• Chemical Production Workshops: Handling containers and equipment with flammable gases and chemicals.

• Natural Gas Stations and Filling Stations: Pressure vessel or pipeline installation operations.

• Pharmaceutical Industry: Used in cleanrooms where dust or organic solvents are present.

• Military and Ammunition Warehouses: High-risk material handling environments requiring strict explosion-proof requirements.

Advantages & Features

• Compact structure, high space utilization
  The crane adopts a compact design with a low building headroom requirement, making it particularly suitable for workshops or warehouses with strict space limitations, helping you maximize the use of plant space.
• Lightweight design, low wheel load
  The equipment features light deadweight and low wheel load, which means lower requirements for the plant structure, helping to reduce your investment in plant civil construction.
• Stable operation, safe and reliable
  1. Strong load-bearing capacity and a rationally designed structure ensure the crane meets the lifting demands of heavy objects in various industrial environments.
  2. Weihua emphasizes product safety and reliability, and this crane inherits these characteristics.
• Flexible operation, convenient control
  1. The electric hoist operates quickly and responsively. Combined with the bridge system’s wide-range mobility, the crane achieves highly flexible operation within the work area.
  2. Offers multiple operation modes, including ground control, cabin control, and remote control, allowing you to flexibly choose the most convenient method based on actual working conditions.
• Easy maintenance, economical and durable
  The product’s components are designed rationally, making them easy to inspect and maintain. This helps reduce your equipment maintenance costs and downtime.

Applications

The LH double-girder overhead crane is widely used in the following locations:

• Machinery manufacturing & processing workshops: For the transfer and assembly of components.
• Warehouses & logistics centers: Efficiently handles loading, unloading, and transportation of materials.
• Metallurgical plant auxiliary workshops: Serves lifting tasks in auxiliary processes.
• Power stations: Used for equipment inspection and maintenance.
• Light textile & food industry workshops: Can replace standard double-girder overhead cranes to meet the production needs of these industries.

Two operation forms are available: floor operation and cab operation. The cab comes in open and enclosed types. It can be installed on the left or right side according to the actual situation. There are three entry directions: side, end, and top, allowing users to choose according to various needs.

Structural Composition

The NLH型 electric hoist double-girder crane has a scientific and stable structure, mainly composed of four core parts:

Advantages & Features

The advantages of Weihua LHB型 explosion-proof bridge crane are mainly reflected in the following aspects:

Specifications

Applications

Thanks to its compact, flexible, and efficient characteristics, Weihua LH型 electric hoist overhead cranes are widely used in the following industries and fields:

• Machinery Manufacturing and Processing Workshops: For transfer and assembly operations of components.
• Metallurgical Industry: Mainly used in auxiliary workshops of metallurgical plants for material lifting.
• Warehousing Logistics and Stockyards: Efficiently completing loading, unloading, and handling of materials in warehouses, stockyards, etc.
• Power Industry (Power Stations): For maintenance and overhaul work of power station equipment.
• Light Industry and Food Industry: Can replace ordinary double-girder overhead cranes for use in production workshops of the light textile and food industries.