Winter anti-freezing and anti-condensation plan for chemical plants

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Comprehensive inspections for anti-freezing and anti-condensation measures in various workshops are carried out, with timely rectification of any issues identified, in order to prepare for the arrival of cold weather... To ensure the safe and stable operation of various units during winter, the following anti-freezing and anti-condensation measures are implemented in the vacuum distillation workshop. I. Principles for winter anti-freezing and anti-condensation measures: 1. Supervise, inspect, and assist various teams in carrying out anti-freezing and anti-condensation tasks, conducting inspections of relevant lines and areas as specified in the routine inspection protocol. 2. All insulation equipment and pipelines must be properly insulated, with no exposed areas or defects; all heat tracing systems should provide heating, and regular inspections should be carried out to prevent condensation in the pipelines. (Activate the companion heat line after receiving the workshop notification.) 3. For the vent valve on the steam pipeline, open it slightly to allow steam to emerge and to discharge condensate water; open it a little as well for the mixture of water and steam, in order to prevent freezing. 4. The equipment that is in use should be properly covered to ensure there is no water left inside and to prevent water from entering and causing cracking. Regularly check the drain valves and steam valves located on the pipe bridges; in addition to insulation, other anti-freezing measures can also be taken. 5. Regularly check the purified and unpurified air lines for water and oil accumulation; make sure that the condensate water in the air tanks is drained, and if necessary, slightly open the vent valves of the air tanks to prevent water from freezing. 6. All water pipelines should always have water flowing through them; if necessary, the drain valves should be slightly opened to prevent freezing. Pay constant attention to changes in water pressure to avoid situations where the pressure is too low, resulting in no flow of water and damage to pipelines, valves, and equipment. 7. Slightly open the inlet and outlet valves as well as the connection valve of the standby hot oil pump to maintain a proper preheating state. When the temperature drops, drain the water accumulated in the casing of the standby cold oil pump, and keep turning the pump shaft to slightly open the inlet and outlet valves in order to preheat the pump and prevent it from being damaged by freezing. 8. The oil and water accumulated inside equipment, pipelines, containers, coolers, condensers, heaters, and cooling water systems of stationary equipment that are under maintenance or out of use must be thoroughly purged and drained. In those areas where thorough purging and drainage is not possible, the connections should be disconnected to remove all remaining fluid. 9. Ensure proper insulation and protection against freezing for fire hydrants, fire steam pipelines, and fire extinguishing equipment. II. Specific measures for preventing freezing and condensation (For the following areas, the instrument parts are to be inspected by the workshop; in cases of sudden temperature drops or when the temperature is below -10°C, the on-duty staff are responsible for supplying steam manually, while otherwise, instructions from the workshop must be followed.) Atmospheric and vacuum distillation unit: 1. Turn on the heavy fuel oil heating line and the vent line ； Notify the finished product workshop to turn on the heavy diesel heating – should it be turned on fully? The normal slag line is heated, and the outlet temperature and flow rate are ensured in a timely manner. 2. When injecting demulsifier and corrosion inhibitor, keep the heat tracing slightly open to prevent freezing; when the water injection line is not in use, close the main valve and drain it. 3. Open the vent at the dirty oil line purge point. 4. Turn on the steam supply for the electrocutting water line, and activate the heating system for the R102 water cutting package. Regularly check the operation of the water cutting line to prevent freezing. 5. Heat tracing for the glass panels of the stripping tower and water cut tank, as well as for the level gauges, shall be turned on. 6. The heating steam for the atmospheric pressure furnace is vented at one point, while the heating steam for the reduced-pressure furnace is vented at one location. Heating for fuel oil turned on. Preheat the backup fuel pump. The return valve is open. 7. After purging the heat tracing lines that have been taken out of service under reduced pressure, vent them. Also purge any water or oil remaining inside the pumps that are no longer in use; slightly open the water circuits of the coolers under reduced pressure and vent from the lowest points. 8. Slightly open each mixed water column; ensure all rubber hoses are in place. 9. Purge the bottom-reduction pump and vent it; close the root valve on the cooling water line and drain the water. Cooling of vacuum unit: drain and vent the water. 10. Bring the fresh water to a slight boil to prevent freezing, and open the connection valve at the end of the circulating water system. 11. Close the root valve of the electro-dehydration water injection system to drain any remaining water. 12. For the alkaline pump that is not in use, remove the plug, rotate the water pump to clean it out, and then vent it. Gas handling unit: 1. Heat tracing for the water cut tanks V9101, V9102, V9104, and V9105 is turned on; heat tracing for all instruments is also activated to prevent freezing and malfunction. For V9101, V9102, V9104, V9105, cut off the water promptly and conduct regular inspections to ensure that the drainage funnels are unobstructed. 2. Heat tracing for the MTBE level gauge and level transmitter should be turned on to prevent failure due to freezing. 3. Turn on the cooling water for each pump; slightly open the outlet of the standby pump to prevent water at the lowest points from freezing. 4. Regularly check and ensure unobstructed drainage of high-pressure and low-pressure gas, and regularly drain condensate from the degassing tank. 5. Regular drainage of condensate from the purification air tank ； The fire steam vent is slightly opened to prevent freezing. 6. When shutting down, the water remaining inside equipment, pipelines, containers, coolers, condensers, heaters, and the cooling water systems for moving equipment must be thoroughly purged and drained. In those areas where thorough purging and draining is not possible, the connections should be disconnected to remove the remaining water. Vent all low points; purge the water line thoroughly and then vent it. 7. Open the mixed water column slightly and ensure all rubber hoses are in place. 300,000-ton gasoline hydrogenation unit: 1. The oil waste line is connected to the coking heat tracing; the heat tracing for V101, V202, and V301’s water separation tanks is activated, as well as the heat tracing for all instruments. For V101, V202, and V301, turn on the heating for the cutwater lines; also turn on the heating for the lean amine solution and rich amine solution. During inspections, pay attention to the glass panel in V206 to prevent freezing. 3. Keep the return line of the injection pump slightly open to ensure an adequate amount of water is injected; during inspections, pay attention to the V205 glass panel to prevent freezing. Keep the outlet of the backup pump slightly open to prevent freezing. 4. Turn on the cooling water supply for each pump, the compressor cooling water, and the cooling water for the light oil station; when shutting them down, drain any remaining water. 5. Heat the oil sludge tank V402 and the vent tank V401, and drain their contents regularly; also drain the contents of V203, the compressor inlet buffer tank, and the waste gas recovery liquid tank on a regular basis. 6. Heat up the corrosion inhibitor ； When shutting down, close the valve at the root of the tower top, purge the pipeline, and open the vent. 7. Check the flow of gas at V201, V202, V101, and V301 through regular venting tests to prevent freezing. 8. Regular drainage of condensate from the purification air tank V406 ； Heat tracing for fuel gas is turned on; the fuel gas buffer tank is drained of condensate regularly ； Slightly open the drain at the end of the steam branch for condensate discharge. 9. During shutdown, the water remaining inside equipment, pipelines, containers, coolers, and the cooling water systems of moving equipment must be thoroughly purged and drained. In those areas where thorough purging and draining is not possible, the connections should be disconnected to remove all remaining water. Empty all low points; blow out and empty the water lines thoroughly.