【Daily Question】Question for 20151111

Nitrogen purge pipeline, circulation replacement pipeline, heat tracing system

Insulation, heat tracing, circulation, water cut-off, continuous drainage.

1. Slightly open the vent valve on the steam pipeline to prevent freezing, but discharge under pressure is not allowed. 2. All trace heaters are supplied with steam for heating, to prevent freezing. 3. For the standby hot oil pump, slightly open the inlet and outlet valves as well as the connection valve to keep it in a properly preheated standby state. 4. For pumps that will not be used for an extended period, close the relevant valves and drain any water or oil remaining in the pipes, pump body, pump base, and oil tank. 5. Any water or oil remaining inside equipment, pipelines, containers, coolers, heaters, etc., that are shut down for maintenance must be thoroughly purged.

Timed condensate removal, maintaining circulation, draining, insulation

Venting, heat tracing, displacement method, long-cycle flow

1. Venting, 2. Heat tracing, 3. Displacement method, 4. Long-circulation flow

1. For equipment and pipelines that have been out of use for an extended period in the plant area, blind flanges should be installed at the connections to the production system, and water accumulation should be drained and the areas cleaned thoroughly together with the production staff. 2. Strengthen the routine inspections of the sealing and cooling areas of backup pump equipment; the cooling water or low-pressure steam supplied to the pumps must not be interrupted, and heating systems must remain functional. Pressure gauges and level gauges should be checked regularly, while the joints of steam and water hoses, as well as other related components, must be kept in a state where steam and water flow continuously. 3. Valves with non-functional electrical switches must not be forced to operate; pumps that cannot rotate should not be started. 4. For instruments with a very high freezing point, heat tracing should be provided, and the temperature inside the insulation should be checked regularly. Insulation cabinets for instruments should be checked regularly to prevent the instruments from freezing. 5. For equipment that is kept in standby mode during winter, the insulation system must not be turned off, in order to prevent production staff from taking measures to reduce energy consumption and emissions. It is necessary to communicate promptly with the production manager to explain the reasons, thus avoiding greater losses as a result of minor oversights. 6. Take proper personal protective measures, dress warmly, and ensure slip prevention when going up and down the tower during inspections; felt can be laid on the steps for this purpose. 7. Regarding instruments, pay attention to the angle valves at the top and bottom of the liquid level gauges on site; if one of these valves freezes and gets blocked, it will affect the accurate measurement of the liquid level. A blockage at the gauge unit of the remote-controlled liquid level gauge will impact mechanical transmission as well as current flow. Affects the true liquid level.

What are the winter measures to prevent freezing and condensation? (At least two points) 1. All heat tracing systems should be activated, and a thorough inspection should be carried out to ensure proper drainage at the lowest points. 2. After the pump is taken out of use, it should be purged with nitrogen. 3. Regularly drain condensate from the bottom of the instrument air line air tank. Prevent instrument air from containing water. 4. If the device’s water line cannot be drained, it should be slightly opened to prevent freezing and cracking. 5. When purging the device, the drain bottom valve should be flushed until steam is emitted and no liquid comes out. Source: Safety Management Network (www.safehoo.com) Full source: http://www.safehoo.com/Live/Live/Fire/201310/327189.shtml

1. Any water or oil remaining inside equipment, pipelines, containers, coolers, heaters, etc., that are out of service for maintenance, must be thoroughly purged. 2. Outdoor cast-iron equipment and fittings must be insulated; any equipment that is open should be covered to prevent water from entering and causing cracking. Regularly check that all cast-iron valves, steam valves, and areas in the pipelines where water may accumulate are properly insulated to avoid cracking. 3. For heavy oil pipelines used for transporting crude oil, residue oil, and catalytic feedstocks, it is necessary to regularly check whether the heat tracing systems are functioning properly in order to prevent freezing. 6.6 ~.4 It is also important to regularly check whether there is water present in the purified air and unpurified air pipelines; any water accumulated should be drained at the lowest points of the pipeline structures as well as in the tanks used for storing purified and unpurified air. If necessary, steam heating should be used to prevent water from being present in the air, as this could cause instrument failures. 5 When the temperature drops significantly, increase the processing volume and the cooling temperature appropriately, and check the instruments that indicate processing failures. 6 All water pipelines should always have water flowing through them; valves at the dead ends of the pipelines should be slightly opened to prevent freezing. It is also important to monitor changes in water pressure to avoid situations where the pressure is too low, which could cause the pipelines, valves, and equipment to freeze due to lack of flow. 7 Slightly open the vent valve on the steam pipeline to prevent freezing, but discharge under pressure is not allowed. 8 All bypass lines are heated with steam to prevent freezing. 9. For the standby hot oil pump, slightly open the inlet and outlet valves as well as the connection valves to maintain a proper preheated standby state. 10. For pumps that are not in use for an extended period, close the relevant valves and drain any water or oil remaining in the pipes, pump body, pump base, and oil tank. 11 All insulation equipment pipelines shall be properly insulated, with no exposed areas or defects. 12 Ensure proper insulation and frost protection for fire hydrants, fire steam pipelines, and fire-fighting equipment. 13 Regularly check the flow and pressure in the steam pipeline system, and control the amount of steam used. 14 When the winter installation is shut down, all water remaining in the pipelines and equipment must be drained, and the areas should be cleaned with air. 15 On snowy days, the snow accumulated on towers, platforms, and ladders should be cleared promptly to prevent slips. 16 Each production team should discuss the status of anti-freezing measures during shift handovers. 17 The heating system of glass plate level gauges should be checked regularly to prevent them from cracking due to freezing. 18 Regularly check whether the drain valve of the heat trace trap is unobstructed to prevent freezing and cracking. 19. Keep the fire protection steam anti-freezing line valves slightly open; ensure that all the purge steam, nozzle atomization steam, stripping steam, and loosening steam are in good condition. Steam should be visible at the vent points. After cutting off the material flow, close some of the steam supply valves as appropriate and keep the vents open. Check all 20 platforms for any water accumulation or ice on the escalators, and clean them up promptly. 21 Waste heat boiler water supply lines to prevent pipeline freezing. 22 Anti-freezing for external heat supply water lines. The 23 fuel oil system operates for two hours on a daily basis at scheduled times to ensure it is in good standby condition.

To prevent freezing and condensation in winter, it is necessary to ensure proper assignment of responsibilities, adequate training and education, regular inspections and corrective actions, sufficient provision of necessary materials, and thorough planning and drills.