Chemistry Q&A | Can liquid chlorine cylinders be lifted with metal chain ropes?

[Question] Can liquid chlorine cylinders be lifted using metal chain ropes? [Answer] No, metal chain ropes should not be used for lifting liquid chlorine cylinders. This is a safety regulation based on the characteristics of liquid chlorine and the risks associated with lifting operations. The fundamental reason is that metal chain ropes introduce multiple high risks that could lead to accident consequences. First, direct risks: 1. Over time, metal chain ropes experience friction and wear at the contact points, leading to a decrease in their strength. 2. Liquid chlorine cylinders (especially those weighing 500kg or 1000kg) are heavy, and during lifting, they may sway or collide, exacerbating the fatigue and damage to the chain ropes. 3. If the chain rope suddenly breaks or deforms severely during lifting, a cylinder weighing hundreds of kilograms could fall from a height. This could result in damage or fracture of the cylinder valve, causing a massive leak of liquid chlorine or rupture of the cylinder itself, potentially leading to physical explosions and chemical leaks. Second, deeper risks: If the environment is humid, the acid generated when chlorine gas comes into contact with water vapor is corrosive. This can accelerate the corrosion of metal chain ropes (especially ordinary carbon steel), reducing their strength and posing a safety hazard.

Reaction equation: Cl₂+H₂O=HCl+HClO.

III. Specification requirements and lifting-related requirements
1. Article 6.2.6 of the "Technical Code for Safety of Chlorine in Chemical Enterprises" (GB 11984-2024) states: "The lifting machinery used for lifting liquid chlorine cylinders shall meet the following requirements: a) the lifting capacity shall be more than 1 times the weight of the full cylinder; b) the overhead crane shall be equipped with travel and height limit protection, and bridge and gantry cranes shall be installed with two different types of height limit devices; c) the anti-unhooking facilities of the lifting machinery shall be intact and dual braking devices shall be used; d) electromagnetic cranes and metal chain ropes shall not be used for lifting." 2. The "First Batch of Key Monitored Hazardous Chemicals Safety Measures and Emergency Response Principles" states: "During lifting, cylinders shall be placed in dedicated baskets that meet safety requirements for lifting. It is prohibited to use electromagnetic cranes, chain ropes for bundling, or use the cylinder valve as the lifting point." Dedicated lifting baskets can stably support the cylinders, avoiding localized stress and preventing collisions. 3. Article 6.2.7 of the "Technical Code for Safety of Chlorine in Chemical Enterprises" (GB 11984-2024) states: "Forklifts shall not be used for loading and unloading cylinders." 4. Article 7.1.4 of the "Safety Regulations for Handling, Loading, Unloading, Storage, and Use of Gas Cylinders" (GB/T 34525-2017) states: "If lifting is required during the handling of gas cylinders, electromagnetic lifting equipment shall not be used. When lifting bulk gas cylinders with mechanical lifting equipment, the cylinders shall be loaded into bundles or baskets and properly secured. Chain ropes, steel wire ropes, bundling, or hooking the cylinder cap shall not be used to lift gas cylinders."

For safety regulations related to cylinder baskets, please refer to the "Technical Specification for Filling Safety of Cylinder Baskets" (T/CCGA 10007-2021).

Fourth, as a final note, accidents caused by the improper use of lifting devices, resulting in the falling and collision of steel cylinders, have occurred from time to time in history. This regulation is a summary of industry lessons, solidifying practice into mandatory requirements. The prohibition of using metal chain ropes to lift liquid chlorine cylinders is a safety requirement based on risk.