Explosion-Proof Crane Selection for Petrochemical Plants

The petrochemical industry is the largest market for explosion-proof cranes—refineries, ethylene plants, coal chemical facilities, fine chemical plants, and fertilizer units all require lifting equipment for maintenance, equipment installation, and routine operations. Because explosive gases or combustible dust are commonly present throughout these facilities, standard cranes cannot be used. Only specially certified explosion-proof equipment is permitted. This article starts with the hazardous area classification system used in petrochemical plants, matches crane types, explosion protection classes, and configuration solutions to each facility type, and provides technical parameters, price ranges, and a step-by-step selection process.

Hazardous Area Classification and Explosion Protection Matching

Explosive hazardous areas in the petrochemical industry are classified per GB 50058 (Code for Design of Electrical Installations in Explosive Atmospheres) and GB/T 3836.15. The areas where cranes are installed typically fall into Zone 1, Zone 2 (gas), and Zone 21, Zone 22 (dust). Zone 0—where explosive gas is present continuously—does not permit any electrical equipment; material handling in these areas must rely on fully pneumatic or fully enclosed systems.

Zone 1 Gas Atmospheres: Explosive gas atmospheres may occur under normal operation. Typical locations: near reactors in refining units, sampling points in chemical plants, and around tank farm breather valves. Zone 1 requires an Ex dⅡCT4 (highest rating) or Ex dⅡBT4 (depending on gas group) explosion-proof crane. Note that hydrogen (minimum ignition energy 0.019 mJ) and acetylene fall under Group IIC and require Ex dⅡCT4; ethylene, propane, and other Group IIB gases can use Ex dⅡBT4.

Zone 2 Gas Atmospheres: Explosive gas atmospheres are unlikely under normal operation and, if they do occur, exist only briefly. Typical locations: non-release areas within petrochemical units and areas more than 2 m from equipment exteriors. Zone 2 permits Ex dⅡBT4 or Ex nA (Increased Safety, Zone 2 only), but the crane industry typically standardizes on Ex dⅡBT4 for interchangeability. Ex dⅡBT4 is the most widely used explosion protection class in petrochemical applications, covering roughly 85% of crane configurations in this sector.

Zone 21/22 Dust Atmospheres: Areas with combustible dust, such as coal preparation workshops in coal chemical plants, plastic powder packaging rooms, and sulfur forming units. Zone 21 requires Ex tD A21; Zone 22 requires Ex tD A22 (A21 is commonly used as a universal configuration). The core of a dust explosion-proof crane is an IP65-rated enclosure plus surface temperature control (≤T135°C or T85°C). For a technical comparison of explosion protection classes and price differences, refer to the explosion-proof bridge crane model parameters and explosion protection class comparison table.

Explosion-Proof Crane Configurations by Plant Type

Refinery FCC Units: The core process unit in a refinery. During maintenance of the reactor and regenerator, internals (cyclone separators, distribution plates, etc.) must be lifted, with individual loads of 5–30t. Recommended configuration: QB Type explosion-proof bridge crane, lifting capacity 16–32t, span determined by building width (standard 22–31 m), explosion protection class Ex dⅡBT4 (the unit's flammable materials are primarily Group IIB gases such as propane and butane), work duty A5 (concentrated use during annual turnarounds). Operation mode: floor remote control + cabin dual control, with an intrinsic safety type Ex ib IIB T4 remote control. Reference price: 16t approx. $44,500–$81,600; 32t approx. $74,200–$126,100.

Coal Chemical Coking Plants: Coal chemical facilities present a unique challenge—both hydrogen (Group IIC gas) and coal dust (Zone 21) are present, so the crane must carry dual certification for both gas and dust explosion protection. Recommended: QBZ Type explosion-proof metallurgical bridge crane with Ex dⅡCT4 + Ex tD A21 dual certification. Lifting capacity 20–50t, span 22–31 m, work duty A6 (frequent operation at coke ovens). Configuration essentials: IIC-grade cast steel flameproof motors, a thermal insulation layer on the main girder to protect against coke oven radiant heat, copper alloy anti-static crane wheels, and reliable rail grounding. Reference price: 20t approx. $71,200–$111,200; 32t approx. $100,800–$170,500.

Chemical Raw Material Warehouses / Tank Farms: Warehouses and tank farms are Zone 2 gas environments with low lifting frequency and small individual loads (pipe valves and fittings ≤2t). Recommended: BZD Type explosion-proof jib crane or explosion-proof electric hoist underslung crane. The BZD explosion-proof jib crane offers lifting capacities of 0.5–5t, jib lengths of 3–6 m, explosion protection class Ex dⅡBT4, and is priced at approx. $7,400–$37,100. The explosion-proof electric hoist underslung crane (running on an I-Beam rail) handles 0.5–10t and is ideal for multi-point coverage, equipped with an explosion-proof remote control. Comparing the two: the jib crane covers a smaller area (270° rotation circle) but requires no runway beam and is simpler to install; the underslung crane covers a linear range but requires an I-Beam rail of sufficient strength at the building roof level.

Equipment Configurations and Price Comparison by Plant Type

Note: Prices are indicative and may vary based on span, lifting height, work duty, and specific configuration requirements. Contact Kelude for a detailed quotation tailored to your project.

Explosion-Proof Crane Selection Process and Key Considerations

Selecting the right explosion-proof crane for a petrochemical application involves a systematic approach. The following steps outline the standard selection process:

1. Define the hazardous area: Identify the zone classification (Zone 1, 2, 21, or 22) for the specific installation location, referencing the plant's area classification drawings.
2. Determine the gas group and temperature class: Identify the specific gases or dusts present and their ignition characteristics to establish the required gas group (IIA, IIB, or IIC) and temperature class (T1–T6).
3. Select the crane type and configuration: Based on lifting capacity, span, and operational requirements, choose between bridge, jib, or underslung configurations, and specify the appropriate work duty classification.
4. Verify certifications and compliance: Ensure the crane and all electrical components carry the required explosion-proof certifications (e.g., CCC Ex) and comply with TSG inspection requirements.

Beyond the selection process, several key considerations are critical for safe and reliable operation in explosive atmospheres:

• Material selection: Use copper alloy or anti-static materials for crane wheels and other components that may generate sparks. Ensure proper grounding of the crane and rail system.
• Thermal protection: In high-temperature environments (e.g., near coke ovens), add thermal insulation layers to the main girder and select motors with appropriate temperature ratings.
• Operation mode: Choose between floor remote control, cabin operation, or a combination based on the application. Explosion-proof remote controls must be certified for the specific hazardous area.
• Installation and inspection: Follow the manufacturer's installation guidelines and ensure all equipment is inspected and certified by authorized bodies before commissioning.

For more detailed technical specifications, model parameters, and configuration options, refer to the explosion-proof bridge crane model parameters and explosion protection class comparison table.

Explosion-Proof Crane CCC Certification & Inspection Requirements

Explosion-proof cranes used in the petrochemical industry must meet the following three compliance requirements:

Explosion-Proof CCC Certification (CCC Ex): Since October 2019, explosion-proof electrical products have been included in the mandatory CCC certification catalog (SAMR Announcement No. 34 of 2019). The explosion-proof motor, electrical control box, junction box, and limit switches fitted to an explosion-proof crane must each hold an individual CCC Ex certificate. The complete crane's Explosion Proof Certificate is issued by the China Quality Certification Centre (CQC) or the Nanyang Explosion-Protected Electrical Apparatus Research Institute (CNEx). The certificate is valid for 5 years and must be renewed upon expiry.

Special Equipment Manufacturing License: Explosion-proof overhead cranes with a lifting capacity of ≥3t fall under the regulatory scope of the Special Equipment Catalog. The complete crane manufacturer must hold the corresponding manufacturing license (Grade A or B). Installation companies must hold an installation license, and the user unit must complete use registration within 30 days before the crane is put into operation. Inspection interval: an annual periodic inspection (including a special inspection of explosion-proof electrical components) is required, carried out in accordance with TSG Q7015-2016.

Specialized Explosion-Proof Maintenance: Per AQ 3009-2007 (Safety Specification for Electrical Equipment in Explosive Atmospheres), an explosion-proof crane must have a device management log and undergo a specialized explosion-proof inspection at least twice a year. The inspection covers: flameproof enclosure sealing surface gaps (≤0.2mm), aging checks on cable entry device seal rings, grounding resistance testing (≤4Ω), and wear inspection of alloy anti-static wheels (copper alloy layer thickness ≥1.5mm). For more details on annual inspections and specialized checks for explosion-proof equipment, refer to Explosion-Proof Overhead Crane Explosion Protection Classes, Parameters & Pricing.

Selection Process and Key Precautions

Step 1: Review the hazardous area classification drawing for the installation site (issued by the design institute or safety assessment agency) to determine if Zone 1/2/21/22 applies. This is the fundamental basis for selecting the explosion protection class.

Step 2: Identify the gas group (IIA/IIB/IIC) and temperature class (T1–T6) of the flammable substances present. The most common temperature classes in petrochemical plants are T3 (≤200°C, e.g., ethylene) and T4 (≤135°C, e.g., hydrogen). Higher temperature classes (up to T6) command a higher equipment price.

Step 3: Determine the lifting capacity based on the maximum load weight × 1.1, the crane span based on the factory building or frame span minus safety distances on both sides, and the work duty based on lifting frequency. Cranes for petrochemical maintenance typically use A5 (medium duty), while continuous operations like coking plants require A6.

Step 4: Verify the scope of coverage and validity period of the supplier's explosion-proof CCC certification. Review the supplier's track record in the petrochemical industry—check if they are an approved supplier for Sinopec, PetroChina, CNOOC, or similar. Kelude Heavy Industry's explosion-proof cranes are listed on the Sinopec EPEC platform and the Yanchang Petroleum supplier system, with products certified by CNEx.

FAQ: Explosion-Proof Crane Compliance & Costs