Synthetic Ammonia Weekly Topic 12/5--12/12: Plant overhaul – share your suggestions on safety management
Thread Content
Synthetic Ammonia Weekly Topics 12/5–12/12: Plant overhauls – share your suggestions regarding safety management. Plant overhauls refer to the periodic maintenance tasks carried out on the plant. The overhaul timing is determined based on factors such as the device’s operating time, equipment issues, catalyst lifespan, feed gas supply, product market conditions, and weather. Overhaul work allows for tasks such as catalyst replacement, cleaning of heat exchangers, and internal inspection of large-scale equipment – maintenance activities that are not possible during normal operation. The quality of major repairs plays a decisive role in the ‘normal, full, optimal’ operation of the installation. At the same time, during the major overhaul, various maintenance tasks are carried out in the plant area. The types include high-risk tasks such as work at heights, concurrent operations, and work in confined spaces. If maintenance personnel lack a proper safety awareness, if various labor protection measures are not in place, and if risk assessment for maintenance plans is inadequate, all these are factors that pose threats to the safety of those performing maintenance tasks. During major repairs, casualties occur from time to time. May I ask: how can the risks associated with maintenance be avoided? Share your suggestions on safety management during major overhauls. (It will be more persuasive to discuss based on one’s own experiences–the accidents that occurred during the major repairs.) We encourage everyone to actively participate in the discussions; those who are proactive will receive higher financial rewards depending on the completeness of their answers. Thank you for your participation!
Key safety considerations for major equipment overhauls are as follows: 1. The system must be thoroughly purged; in particular, tasks involving open flames or work inside towers and tanks must be carried out strictly in accordance with established procedures, without relying on experience. 2. Proper protection measures must be in place for work at heights and other similar tasks, and these tasks must be conducted strictly in line with the requirements specified in the work orders. 3. Proper purification must be ensured when starting up the system; rigorous analysis is required, and further work is prohibited if the analysis results are unsatisfactory. 4. Appropriate personal protective equipment must be used during system maintenance. 5. All maintenance and testing activities must be carried out strictly in accordance with the established maintenance procedures and safety regulations; it is strictly forbidden to carry out work in violation of these rules based on experience.
The precautions for the major overhaul of ammonia synthesis are as follows: 1. Clearly define the contents of the overhaul, list them down for record-keeping, and avoid acting blindly. 2. Tasks for maintenance assigned to a specific person. 3. Thorough replacement, based on analyzed data, with appropriate labor protection equipment in place. 4. Single-person operation is prohibited during maintenance; at least 2 people must be present. 5. When entering the tower or tank, all relevant work permits must be in place, along with personnel from the safety department and emergency response team. 6. Hot work must be carried out with a work permit, a supervisor, and analysis results.
A warning sign should be hung at the open manhole of the tower tank.
1. Maintenance work shall not begin if safety measures are not implemented； 2. Equipment that has been shut down for maintenance must not be put back into use without a thorough inspection ； 3. Working at heights is prohibited without a high-altitude work permit, without wearing safety belts, or when scaffolds and stepping boards are not secure ； 4. Do not proceed with the operation if the system replacement is not thorough ； 5. Protective equipment must be prepared in advance ； 6. In the workplace and when external workers are carrying out tasks, there must be a dedicated person to supervise them
Reply 1# shfuchenko: Comply strictly with the eight requirements for entering a container, the six prohibitions regarding hot work, and the fourteen restrictions; there must be dedicated personnel to supervise, and strict adherence is necessary. 1. An application must be submitted and approved first. 2. Safety isolation must be carried out. 3. The power supply must be cut off, and safety lighting must be used. IV. Replacement and ventilation must be carried out. V. Safety analyses must be conducted according to the specified time requirements. VI. Required protective equipment must be worn. VII. Someone must monitor from outside the device and remain at their post. VIII. Emergency backup measures must be in place
Reply 1# shfuchenko: The six strict prohibitions regarding hot work must be strictly enforced; any instance of such violations must be dealt with immediately, without any leniency. The rules are as follows: 1. Hot work is prohibited without an approved permit. 2. Hot work is prohibited if the area cannot be properly isolated from the production system. 3. Hot work is prohibited if the area has not been properly cleaned or purged. 4. Hot work is prohibited if flammable materials in the surrounding area are not removed. 5. Hot work is prohibited if hot work analysis is not conducted on time. 6. Hot work is prohibited in the absence of appropriate fire safety measures. Previous post: A brief explanation of the six strict requirements for operators
1. Isolate the boundary area and the equipment containing materials using blind flanges. 2. Isolate the area to be overhauled, replace components, and conduct analysis; work may proceed only after approval. 3. Entry into the equipment must be carried out in accordance with regulations; replacement, ventilation are required, and analysis results must be satisfactory. 4. For hot work, a hot work permit must be obtained as required; work shall not proceed without approval. 5. When maintaining equipment, attention should be paid to hygiene to avoid contaminating it. 6. A safety analysis must be conducted for hot work, and it must be supervised by a designated person. 7. For mechanical maintenance, the power supply must be cut off and the equipment replaced.
Simply put, I think the most important aspect of safety is to pay attention to it. Early stage: Necessary plans and responsible persons are required to predict the problems that may arise during the major repair ； During maintenance, conduct more inspections and verifications.
Nitrogen shielding may be used during the catalyst loading process; it is essential to pay attention to the safety of personnel entering and leaving the area to prevent asphyxiation accidents. Proper protection must be worn when entering the equipment, and attention should also be paid to whether there are any damages to the internal structure of the equipment, in order to avoid injuries during maintenance work
1. Conduct hazard identification for the equipment to be overhauled and take necessary measures. 2. Develop appropriate safety and technical measures for major projects (such as catalyst replacement in synthesis systems). 3. The units involved in the major overhauls must possess the required qualifications. 4. Strictly follow operating procedures or work permits (such as those for high-voltage electrical maintenance). 5. For the equipment and pipelines involved in the overhauls, thorough purging is necessary, and sample analysis must be carried out before operations such as welding are performed. And assign a specific person to be in charge. 6. Maintenance work must ensure no combustion, no explosion, no poisoning, no leakage, and no water hammer, in order to guarantee the quality of purging and displacement.