National Administration of Quality Supervision: Notice on Opinions Regarding the Rectification Work for Metallurgical Lifting Machinery

　　To the Quality and Technical Supervision Bureaus of各省, Autonomous Regions, and Directly-Administered Municipalities:

　　On April 18, 2007, a catastrophic accident occurred at Qinghe Special Steel Co., Ltd. in Tieling City, Liaoning Province, when a molten steel ladle overturned, tragically resulting in the deaths of 32 workers at the scene. In accordance with the requirements outlined in the "Notice on Launching Special Inspections for Hidden Hazards in Special Equipment and Targeted Rectification Actions for Lifting Machinery" (Guo Zhi Jian Te Han [2007] No. 355) issued by the General Administration, local authorities have already begun implementing relevant measures. Preliminary findings indicate that more than 2,000 non-metallurgical lifting machines originally intended for use in the metallurgical industry have been identified in just two provinces—Liaoning and Jiangsu alone. To ensure the safe operation of these equipment types, and taking into account the specific production and business conditions of enterprises, after careful consideration, we hereby issue the following notice regarding the rectification efforts for metallurgical lifting machinery:

　　I. Requirements for the Remediation of Non-Metallurgical Lifting Equipment Used in Handling Molten Metals

　　(1) For facilities already using general-purpose bridge cranes to lift molten metal, these should be replaced with casting cranes that meet the requirements of JB/T 7688.15—1999, "Technical Specifications for Metallurgical Cranes — Foundry Cranes." If, due to factors such as plant layout or foundation limitations, a unit is unable to replace its crane with a casting model, it must not only comply with the relevant regulations, codes, and standards applicable to general-purpose bridge cranes but also undergo modifications to ensure the original crane satisfies the following basic technical requirements:

　　1. Use a metallurgical crane-specific electric motor; in environments where the temperature exceeds 40°C, an H-class insulated motor should be selected.

　　2. Equipped with two independently operating brakes (dual braking system);

　　3. A load-limiting device must be installed;

　　4. Equipped with dual limit switches (double-limit devices) featuring different types of mechanisms—typically combining a weight-based and a rotary design—and each switch should activate a separate circuit-breaker. Additionally, cranes with a lifting height exceeding 20 meters must also be fitted with a descent-limit switch as needed.

　　5. Lifting mechanisms employing thyristor stator voltage control, eddy-current brakes, regenerative braking systems, thyristor-based power supplies, DC generator-driven speed control, and other speed-regulating methods that could potentially lead to overspeed—along with general-purpose bridge cranes rated at 20 tons or more designed for handling molten metal—must be equipped with overspeed protection.

　　6. The lifting mechanism should feature positive and reverse contactor fault protection to prevent the motor from losing power while the brake remains energized, which could otherwise lead to stalling.

　　7. The protection levels of all electrical equipment must comply with the relevant standard specifications.

　　8. Lifting machinery operating continuously in high-temperature environments requires protective measures for their electrical control systems.

　　9. Select steel cables suitable for high-temperature applications and ensure they have an adequate safety factor.

　　10. Cast iron pulleys must not be used;

　　11. Cranes originally rated below A6 (excluding A6) must be operated at reduced load capacities, with the extent of reduction determined based on actual working conditions. However, after reducing the load, the specified lifting capacity must not exceed 80% of the original rated lifting capacity.

　　(II) For all types of lifting machinery already equipped with electric hoists as lifting mechanisms and having a rated lifting capacity exceeding 10 tons, the lifting of molten metals is prohibited.

　　(III) For all types of lifting machinery already equipped with electric hoists as lifting mechanisms, where the rated lifting capacity is 10 tons or less and used to handle molten metal, the original crane must be replaced or retrofitted to meet the following basic technical requirements:

　　1. Ordinary electric hoists must not be used as lifting mechanisms;

　　2. Equipped with a support brake and a safety brake;

　　3. Features dual limiters of different designs for upward movement (cranes with a lifting height exceeding 20 meters must also be equipped with a limit switch for the lower extreme position).

　　4. Equipped with a load-limiting device;

　　5. Electric hoist with high-temperature thermal insulation protection;

　　6. Must have an adequate safety factor suitable for lifting molten metal, with a service level of M5 or higher (including M5).

　　7. Select steel cables suitable for high-temperature applications and ensure they have an adequate safety factor.

　　8. Whenever possible, use remote control methods that keep operators away from heat sources; otherwise, a safe passage for personnel must be established.

　　(4) The modification of the aforementioned crane must be carried out by a qualified unit holding the necessary renovation permit. Before proceeding with the modification, notification procedures must be completed. After the renovation is finished, the crane must undergo supervised inspection by a certified inspection and testing organization, following the requirements outlined in the "Supervisory Inspection Rules for Lifting Machinery" and as specified in this document. Only after passing the inspection can the crane be put into operation according to regulations.

　　(5) The retrofitting of cranes used for lifting molten metal must be completed by June 30, 2008. Units currently using these cranes should immediately develop replacement plans or retrofitting schemes and promptly begin implementation; otherwise, the equipment must be taken out of service. During the retrofitting process, users are required to maintain close supervision and must implement effective measures to ensure the safe operation of the equipment at all times.

　　(6) The periodic inspection interval for cranes used to lift molten metal has been shortened from 2 years to 1 year.

　　II. Requirements for Newly Manufactured Cranes Installed to Lift and Transport Molten Metal

　　Newly manufactured and installed cranes designed for lifting molten metal refer to lifting equipment intended for this purpose that has been produced and installed starting from the date of this document’s publication. This excludes cranes used for molten metal handling that have undergone major overhauls, modifications, or relocation.

　　(1) Requirements for newly manufactured cranes installed to lift molten metal are as follows:

　　1. Cranes with a rated lifting capacity of 75 tons or more must use casting cranes that meet the requirements specified in JB/T 7688.15—1999, "Technical Specifications for Metallurgical Cranes — Casting Cranes."

　　2. For cranes with a rated lifting capacity of less than 75 tons, a general-purpose bridge crane with a working duty class of A7 (including A7 and above) should be selected. However, their configuration and other requirements must meet all 11 basic technical conditions and corresponding standards outlined in Article 1(i) for the upgraded crane described earlier.

　　3. Cranes equipped with electric hoists as lifting mechanisms for handling molten metal must be used only in applications where the rated lifting capacity is 10 tons or less. Additionally, their configuration and other requirements must meet the revised basic technical conditions and corresponding standards outlined in Article 1(3) above. Notably, the operating duty category of the electric hoist must be upgraded from M5 (including M5) and higher to M6 (including M6) and above.

　　(II) Cranes used for lifting molten non-metallic materials (at temperatures lower than molten metals) and hot, solid metals may have their requirements appropriately relaxed based on the level of hazard in the workplace; alternatively, they can also be handled according to the above-mentioned guidelines.

　　Local bureaus of quality and technical supervision should promptly implement effective measures to rectify the use of non-metallurgical cranes in the metallurgical industry, ensuring that similar accidents do not recur. Any issues encountered during this process should be reported without delay to the Bureau of Special Equipment Safety Supervision under the General Administration.