Regarding night inspections of hydrogen-related systems

I. Core Laws, Regulations, and Standard References The management of night-time inspections for hydrogen systems is primarily governed by the following **laws, regulations, standards, and industry best practices: 1. \"Technical Regulations for Safe Use of Hydrogen\" (GB 4962): This is the most fundamental **standard. It explicitly requires the establishment of a system for conducting regular nighttime inspections with lights turned off to check for hydrogen leaks. This is almost a mandatory technical requirement that all petrochemical companies involved in hydrogen handling must comply with. 2. The “Regulations on Hydrogen Safety Management” and the ten regulations regarding the production and use of hydrogen: These regulations require that, in order to produce and use hydrogen, it is necessary to establish comprehensive “technical safety procedures for hydrogen production” based on the characteristics of the production processes and the actual needs of safe production. It often also includes requirements for inspecting the hydrogen-handling systems. 3. The Regulations on the Safety Management of Chemical Hazardous Materials (Decree No. 344 of the State Council): As a higher-level regulatory framework, it establishes the basic guidelines for safety management throughout all stages of handling chemical hazardous materials – including production, storage, use, distribution, and transportation – for substances such as hydrogen. It requires enterprises to assume their primary responsibilities and to establish comprehensive safety management systems. 🔍 II. Key aspects and requirements of night inspections Night inspections, especially those conducted with the lights turned off, are an effective way to detect hydrogen leaks. Inspection Categories: Key Contents and Requirements 🔥 Dark-Light Inspection: Regularly turn off the lighting at night and, in darkness, check whether there are pale blue flames (indicating minor hydrogen leaks and combustion) or \"white smoke\" (resulting from the condensation of high-pressure hydrogen leaks) at static sealing points such as high-temperature and high-pressure hydrogen flanges, valves, and pipes. 🧰 Routine inspections: Even when there is lighting, night inspections should include checking whether the equipment’s operating parameters (temperature, pressure, flow rate) are within normal ranges, as well as looking for any abnormal noises, vibrations, or unusual odors. 📝 Recording and Disposal: All inspection findings must be recorded in detail. Upon detecting potential issues such as leaks, report them immediately according to the established procedures (such as notifying the control room), and take action promptly in line with the emergency plan, thereby achieving \"early detection, early identification, and early resolution\". 📋 III. Inspection Frequency and Personnel Requirements · Frequency: Companies usually incorporate light-off inspections as part of their regular maintenance schedule. Some companies require at least 2-4 sessions per week (for example, on Mondays, Wednesdays, Fridays, and Sundays evenings), while others hold them at fixed times each month. The specific frequency must be determined based on the characteristics of the device, the risk level, and the condition of the equipment. · Personnel: · The inspection work must involve technicians in process engineering, equipment management, and safety, as well as the operators on duty, who shall carry out a thorough check in accordance with their respective areas of expertise. · Before starting work, one must receive specialized training on the flammable and explosive nature of hydrogen as well as relevant safety techniques; only after passing the examination can they begin working. · According to the Labor Law, night shifts (usually defined as from 22:00 to 6:00 the following day) are entitled to a night shift allowance. ⚠️ IV. Other Key Safety Management Provisions The safety management of hydrogen-handling systems is a systematic effort; night inspections are just one part of it. You also need to pay attention to the following: 1. Equipment management and material requirements: · Conduct regular technical analyses for hydrogen corrosion and hydrogen embrittlement in high-pressure hydrogen-handling equipment, as well as systematic leak checks. · The connection pipes for filling hydrogen cylinders must be made of copper and copper fittings; the use of rubber products is strictly prohibited to prevent accidents caused by static electricity or material incompatibility. 2. Operating safety regulations: · It is strictly prohibited to release hydrogen directly inside the equipment or factory building. Purging and displacement must be safely vented through the flare network. · Before introducing hydrogen or filling the device with hydrogen, it must be purged and replaced with an inert gas such as nitrogen until system sampling and analysis show satisfactory results. · During hydrogen filling, collisions and impacts are strictly prohibited; hydrogen cylinders must not be placed near heat sources, and protection from sunlight is required in summer. 3. Emergency response: · In the event of a large-scale leak or accumulation of hydrogen, immediately cut off the hydrogen supply, use steam to create a shielding effect or implement forced ventilation; any operation that could generate sparks must be strictly avoided. 💎 Summary and Recommendations: The key to managing hydrogen systems at night is the regular nighttime inspection with lights turned off, as required by the \"Technical Regulations for Safe Use of Hydrogen\" (GB 4962). To ensure safety, it is recommended that your company: 1. Institutionalize the process: Clearly include nighttime light-shutoff inspections in the company’s safety procedures, specifying the frequency, responsibilities of personnel, and the relevant processes. 2. Training: Ensure that all relevant personnel are trained to properly identify signs of leaks and understand the emergency response procedures. 3. Documentation and improvement: Record in detail the results of each inspection and the actions taken to address any identified issues, conduct regular evaluations, and pursue continuous improvement.

GB 4962-2008 – Safety Technical Regulations for the Use of Hydrogen: 3 chapters have been read; no information regarding night inspections was found, nor is there any explicit requirement to establish a system for conducting regular nighttime inspections with lights turned off to detect hydrogen leaks. Could the expert please point out which specific part it is?