Sharing of winter anti-freezing experiences: Anti-freezing and anti-condensation solutions for equipment and facilities

Thread Content

This post was last edited by tianyewei on 2017-11-21 08:42. With winter approaching, proper anti-freezing and insulation measures are essential prerequisites for safe and stable production. In light of the characteristics of our unit’s equipment and the lessons learned from past anti-freezing and insulation efforts, this anti-freezing and insulation plan has been formulated, and all staff members and professionals are required to adhere strictly to it. I. Organizational Structure: The Safety Production Department has established a leadership team for winter anti-freezing and insulation measures, which is responsible for conducting regular inspections of these measures on site on a daily basis, as well as addressing any issues that arise promptly. Team Leader: Deputy Team Leader: Members: II. Purpose of the System 1. Conduct thorough inspections and carry out timely repairs: Inspect the insulation and heating systems of equipment and pipelines; repair or modify those areas where the heating is inadequate or the insulation is damaged, and add insulation to those areas that lack it but require it. During winter, any areas that require renovation or supplementation are addressed promptly. 2. Strengthen inspections and focus on prevention: Personnel in various teams must carry out regular inspections, and be proactive in anticipating freezing issues related to machinery, pumps, containers, pipelines, instruments, electrical equipment, and other facilities, in order to prevent various freezing-related accidents from occurring. Take measures to address issues as they are identified. Heat exchange equipment, equipment with coils, as well as pumps must be carefully inspected. The readings on the local gauges and those displayed on the DCS for all pressure vessels, storage tanks, and pumps should not deviate significantly. In case of any abnormalities, the crew must promptly go to the site to conduct inspections and take action to address them. Adjust measures such as heat tracing and continuous water flow in a timely manner according to weather changes, while also taking proper personal protective measures to stay warm. 3. Assign responsibilities and implement a reward and punishment system: Each team shall conduct a thorough inspection of the equipment before taking over; if no issues are detected, the person on duty at the time of takeover will be held responsible if problems are found later. During winter, a duty-based system is implemented for anti-freezing and anti-condensation measures; whoever is on duty is responsible. Teams that experience freezing shall be fined as appropriate. Reward the teams that performed well in anti-freezing and anti-condensation work that month (with no pipelines, valves, or equipment freezing). 4. Strengthen management and summarize experiences; in the event of freezing accidents in process pipelines, take timely measures to clear the pipelines, and after clearing them, ensure proper insulation and heat tracing ； When the equipment suffers damage due to freezing, take immediate measures to isolate it and carry out repairs. In the event that freezing occurs in instruments and electrical equipment, it must be reported to professionals promptly for handling. Establish a ledger for freezing and condensation incidents to record such accidents and draw lessons from them. 5. Save energy and reduce consumption to lower costs; pay attention to conserving energy and minimizing power usage, and adjust the settings for heating, continuous water flow, and steam as appropriate based on weather conditions. III. Key Points of Work 1. Moving Equipment 1.1 The cooling water for the pump body, the bearing housing, the supports, and the end faces of the pumps must all be turned on to ensure unobstructed flow; water should be visible in the flow sight glasses or observation windows. It is also necessary to maintain uninterrupted heat supply to the pump equipment. 1.2 The cooling water in idle pumps must be drained completely, the medium inside the pumps should be purged, and any water remaining in the pump bases must be blown away. The standby equipment must have the medium in its pump drained. The standby pump, when not in use, should be rotated periodically as required by the inspection procedures; if the pump cannot be rotated, it shall not be put into use. After switching between the operating pump and the standby pump, measures must be taken promptly to prevent freezing and condensation. 1.3 During operation, the chiller must maintain unobstructed circulation water flow. If it is to be out of use for an extended period, the inlet and outlet valves for the circulation water should be closed to drain all the circulation water from the equipment, while simultaneously activating the circulation water bypass line. 1.4 The workshop circulation pump should have its heating maintained and its circulation water pipelines kept unobstructed; it is necessary to rotate the pump shaft before starting it up after a long period of shutdown. 1.5 When pumps such as exhaust gas absorption pumps, sewage pumps, and circulation water pumps are taken out of use, the working fluid inside the pumps must be completely drained. 1. When the 1.6-slitting machine’s material trough is not in use for an extended period of time, the heating should be turned up slightly or the fluid within it should be drained, to prevent the heating jacket from freezing damage. 1.7 During each inspection, the refrigerated dryer must be manually operated to open the drain valve in order to remove the condensed liquid; the refrigerated dryer should be shut down first before the air compressor is stopped ； 2. Static equipment 2.1 Equipment body: Keep the heating pipelines unobstructed for regularly used equipment; for equipment that is not in use, the heating coils can be vented ； 2.2 For unheated water-containing containers such as vacuum systems, liquid should be drained from the lowest point in a timely manner ； In particular, for equipment that uses circulating water for cooling, it is essential to turn on the circulating water bypass when cooling is not required. At the same time, the inlet and outlet valves for the circulating water must not be closed simultaneously to prevent them from cracking due to thermal expansion ； 2.3 For decommissioned coolers, the water circulation must be maintained; alternatively, close the upper and lower inlet/outlet valves to prevent air from entering the medium inside the cooler. The drain valves at the top and bottom of the cooler should be kept open, while the connecting valves for the upper and lower water lines should be slightly opened ； 2.4 Safety spraying: The safety spraying systems in **tank areas** should drain any remaining liquid from the pipes promptly when the water supply is stopped, so that no liquid remains inside the pipes ； 2.5 Safety accessories: Strengthen the inspection of safety valves and rupture discs. For pressure gauges, temperature gauges, and level indicators on pressure vessels, while ensuring proper insulation, regular inspections must also be carried out. Pay attention to comparing the readings of on-site gauges with those transmitted remotely; any discrepancies should be addressed promptly and relevant professionals notified to prevent accidents. 2.6 When the cooling tower is out of use, the water stored in the tower’s pipelines must be drained, as well as the water in the makeup water pipelines ； During use, in case of low-temperature weather, it is necessary to keep the water supply pipeline flowing continuously. 3. Building Facilities 3.1*** When the water heater is not in use for an extended period or during extremely cold weather, drain all water from the system to prevent freezing damage ； 3.2 The floors and stairs must be made slip-resistant; ensure that there is no water accumulation on them. After rain or snow, take action promptly to prevent freezing and avoid falls. In areas where it is difficult to deal with the issue, felt can be laid on the steps to prevent ice formations. 4. Material pipelines 4.1 Valves that cannot be opened or closed during winter production should not be forced to do so; frozen valves should be thawed using warm water or slowly heated with a small amount of steam, to prevent damage caused by sudden heating. 4.2 During the production process, for pipelines carrying materials that tend to condense, they should be purged as thoroughly as possible when conditions permit; in particular, discharge pipelines and loading pipelines should be manually purged to prevent condensation of materials within them. 4.3 The focus is on the discharge route for easily solidifying products: finished product discharge, slicing, and loading ； 5. Utility Systems 5.1 Circulating Water System: The temperature of the circulating water should not be kept too low; the pipelines must remain unobstructed, and cross-connections should be established as appropriate. Special attention should be paid to the water supply pipelines and valveless filters. After the circulating water pumps are switched regularly, the standby pump must be drained completely ； The critical area is the circulating cooling water for the pumps. 5.2 Compressed air system: It is necessary to control the water content in the compressed air system; to prevent damage to pneumatic equipment or production accidents, it is required that during inspections, the drain valves at the lowest points of the instrument air buffer tanks **** as well as those at the lowest points of various instrument air distribution stations in the production area be opened sequentially. 5.3 Steam system: Ensure that all steam trap devices at the lowest points within the installation are functioning properly; any malfunctions should be addressed promptly. The steam traps located at the lowest points of the steam pipes at the ends of the pipe trays should be opened as appropriate, in order to allow for proper drainage and to maintain flow in the steam pipes. For fire protection systems, steam vents at the highest points as well as traps at the lowest points should be used to keep the flow ongoing ； Key areas include the low-point condensate drains in steam pipelines at steam**,** tank farms, ** tank farms, ** tank farms, and between **car platforms**, etc. 5.4 Nitrogen system: During inspections, nitrogen is randomly released from the system pipelines via drain lines to check for moisture content. 5.5 Hot water system: The temperature of the hot water system should not be set too low to ensure smooth circulation throughout the system. For sections that are not in use, cross-connections or bypass systems should be activated; in particular, it is essential that the liquid level in the hot water tank never drop below 30%. 6. Activate all heating elements in the heating system, ensure that the heating works properly and that the steam traps function correctly; address any issues promptly if they arise. Keep the low-point drain valves on the steam pipelines and the end valves on the water pipelines slightly open, so that the medium inside the pipes remains in a flowing state. Any leaks detected during inspections must be repaired promptly. The key areas are the heat tracing distribution stations in Building *** and Room ** of the workshop, as well as in the **** tank farm ； 7. Water supply system 7.1 Process water: The pipes of the industrial water supply system are mostly buried underground, with only certain sections extending above the surface. The parts of the pipelines that are above ground must be insulated, especially the valves. When the system is not in use, the shut-off valves should be closed and the drain valves opened to empty any water remaining in the pipes. Measures such as keeping water flowing continuously should be taken as appropriate, depending on temperature changes, to prevent freezing. 7.2 Eye wash stations and fire water: Close the bottom valve to drain the pipes, or maintain a continuous flow of water to prevent freezing. 7.3 Domestic water: A root valve is installed indoors at the water source outside the gatehouse; after use, the indoor root valve must be closed to drain all the water from the outdoor pipes. In extremely cold weather, it may be appropriate to turn on the water supply in the control building to keep it flowing, thereby preventing the domestic water pipes from freezing. 8 Electrical equipment: 9 Instrumentation equipment: Strengthen the inspection of measuring and control instruments such as pressure gauges, temperature gauges, and sensors; report any abnormalities to the relevant technical personnel for handling promptly. 10 Personal protection: Workers working outdoors in winter should keep warm; they need to be careful to avoid slipping during inspections. Those who are working outdoors for extended periods should take regular breaks to stay warm or work in shifts. 11 Specific tasks for anti-freezing and heat preservation during parking: a. Empty all steam pipes and circulation water pipes that do not need to remain in operation. b. Close all inlet and outlet valves of the pumps, open the inlet and outlet drain valves to empty the system, and require the pumps to be rotated manually every 2 hours. c. Drain all pressure gauge flexibles and machine pump cooling water pipes at the site. d. Fire suppression systems, eyewash stations, industrial water pipes, and steam pipes should be kept slightly open as appropriate depending on the actual conditions. IV. Division of Responsibilities 1. The task of preventing freezing and condensation in fire protection, environmental protection, and occupational health facilities is the responsibility of the safety department ； 2. The task of preventing freezing and condensation in instrumentation equipment is the responsibility of the instrumentation team ； 3. The anti-freezing and anti-condensation measures for electrical equipment are the responsibility of the electrical specialty ； 4. The anti-freezing and anti-condensation measures for steam pipelines and building facilities are the responsibility of the equipment department ； 5. The task of preventing freezing and condensation in the dynamic and static equipment as well as pipelines used in production is the responsibility of the operation department and the operating teams, with the support of the equipment specialists ； 6. The anti-freezing and anti-condensation measures for facilities used by other departments are the responsibility of those departments ； V. Evaluation Measures 1. Based on the records and handling lists related to freeze prevention and heat preservation, rewards shall be given to teams and individuals who performed actively in this activity. 2. Those who, as a result of delayed action or negligence during this event, cause equipment (pipelines) to freeze and suffer damage or lead to the shutdown of the installation, will be punished depending on the severity of the circumstances. VI. Precautions for Operation: In line with the principle of saving energy and reducing consumption, the persons in charge of each area should adjust the opening degrees of the valves for continuous water flow and steam condensate drainage in a timely manner according to weather changes.