Special thread on safety measures against freezing and condensation in chemical plants

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This post was last edited by Shutong on 2015-10-15 at 11:10. It is a dedicated thread for discussing safety measures to prevent freezing and condensation in chemical plants, focusing mainly on the challenges faced by such plants during winter. I’ll start the discussion; those who mention things I haven’t covered will be rewarded for their contributions. A few days ago, I sent out some guiding suggestions regarding prevention of freezing and condensation to various production units, but I’m not entirely satisfied with them. Those who provide additional suggestions will be rewarded, and everyone is welcome to raise questions so we can solve them together. 1. Conduct inspections along the prescribed routes and according to the specified procedures, and address any issues found as soon as possible. 2. The functional departments of each branch factory supervise and assist the workshops in carrying out anti-freezing and anti-condensation measures. 3. Check for any water or oil remaining inside disabled equipment, pipelines, containers, coolers, etc., and ensure that they are thoroughly purged. 4. Outdoor cast-iron equipment and accessories must be insulated; equipment that is in use should be covered to prevent rain, snow, and water from entering and causing freezing damage ； Regularly check that the cast-iron valves and steam valves on the pipe racks, as well as the areas in the dead corners of the pipelines, are properly insulated to prevent freezing and cracking. 5. For important pipelines used for transporting liquid media and chemical materials, it is necessary to regularly check whether the heat tracing is unobstructed to prevent freezing. 6. Regularly check the instrument air (purified air), utility air (unpurified air), and nitrogen pipelines for water accumulation. Also, drain any remaining water at the lowest point of the gantry, as well as in the tanks for purified and unpurified air; if necessary, use steam heating to prevent water from being present in the air, which could cause instrument failure. 7. When temperatures drop significantly, increase the processing volume and cooling temperature appropriately, and check the instruments indicating processing failures. 8. All water pipelines should always have water flowing through them; small relief valves should be installed in areas where flow is restricted to prevent freezing. It is also important to monitor changes in water pressure to ensure it remains at an adequate level, thereby preventing the pipelines, valves, and equipment from being damaged due to frozen water. 9. On steam pipelines without steam traps, a slight opening in the vent valve should be provided to prevent freezing, but discharge under pressure is not allowed. 10. All heat tracing lines are in use to prevent freezing ； Regularly check whether the steam trap used for heat tracing is functioning properly to prevent freezing and cracking. 11. Slightly open the inlet and outlet valves as well as the connection valve of the standby hot oil pump to maintain a proper preheated standby state and prevent condensation. 12. For pumps that will not be in use for an extended period, the relevant valves should be closed. Blind flanges should be installed at the connections between the equipment and pipelines that will not be used for a long time and the production system. Any water or oil remaining in the pipelines, pump bodies, and pump base tanks should be removed, followed by cleaning with purified air. 13. The insulation of all equipment and pipelines must be in good condition, with no exposed areas or damage. 14. Ensure proper insulation and protection against freezing for fire hydrants, fire steam pipelines, and fire-fighting equipment. 15. Regularly check the steam pipeline system, pressure, and control the steam consumption properly. 16. For equipment left outdoors, prevent water and snow accumulation to avoid damaging it due to freezing. 17. In snowy weather, the snow accumulated on towers, platforms, and ladders should be cleared promptly to prevent slipping. 18. Each production team should discuss the anti-freezing work status at the shift handover meeting. 19. Regularly inspect the heating system of glass plate level gauges to prevent freezing and cracking. 20. Ice slush under pipe racks and platforms must be removed at all times to prevent injuries from falls. 21. The venting of utility system pipelines, valves, and heat tracing within the scope of each workshop should be checked regularly, and any issues found must be addressed promptly. 22. It is necessary to ensure that the device is protected against freezing and condensation, while also avoiding excessive discharge. During the day, when temperatures are high, the various discharge points should be adjusted to a lower level, and then reopened to a higher level at night. Difficult issues related to mechanical equipment – submit here