Protection and Management Plan for Shutdown Equipment

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1. Purpose: To ensure that the company’s installations and equipment remain in good condition during periods of shutdown, thereby providing a solid physical foundation for resuming production in the future. 2. Responsibilities 2.1 Each production workshop is responsible for anti-freezing and anti-condensation measures, as well as the inspection, maintenance, and management of on-site equipment. 2.2 The Electrical and Instrumentation Workshop is responsible for the operation, maintenance, and protection management of electrical and instrumentation equipment during shutdown periods. 2.3 Kaisen Company is responsible for the protection and management of rotating equipment. 2.4 The Maintenance Department is responsible for managing the company’s shut-down equipment, formulating plans, implementing specific protection measures, and overseeing their execution. 2.5 The Production Department is responsible for anti-freezing and anti-condensation management. 2.6 The Security Department is responsible for the security management of on-site equipment. 3. Management Plan 3.1 Maintenance Plan for Rotating Equipment 3.1.1 Remove all materials from the equipment during shutdown to prevent condensation; it is prohibited to empty the pumps during shutdown to avoid seal leaks. The maintenance of equipment includes scheduling, recording, and inspection. 3.1.2 Reset inspection cycle: First week. 3.1.3 Turning the pump: The pump should be turned once a day, with white for odd days and red for even days. Directly connected disc motor fan for magnetic pump ； If the coupling guard prevents the machine from being rotated, the coupling guard can be removed and stored in the workshop, with proper record-keeping to be maintained ； The marking requirement for vertical equipment specifies white on the east side for a single day. 3.1.4 Equipment involving oil circulation for turning the shaft: Perform this operation once a week, for no less than 30 minutes each time; the shaft should be turned while oil is circulating, and in the case of manual oil injection, 10 turns downward are required ； With a heater that can raise the temperature to above 20°C, it is possible to start the oil pump ； Power is restored during normal outages or oil leaks. 3.1.5 Principles for refueling equipment: The bearings should be able to come into contact with the lubricating oil during shaft rotation. The amount of lubricating oil can be increased appropriately; it is recommended to fill the pump to the maximum level, with the oil level 10–20 mm above the marked level line in the case of a column-type oil level indicator. Apply grease before the equipment stops operating. 3.1.6 Pumps in carbon steel systems: The protection of turbine equipment is carried out together with the system. Thanks to the shut-off function of the pump’s check valve, the turbine’s emergency shut-off valve, and the speed control valve, it is ensured that all areas are protected during chemical dosing. The compressor and hydrogen press are protected by nitrogen filling, with a nitrogen pressure of 1 Kpa to 5 Kpa. 3.1.7 Removal of the existing belt on the equipment ； For areas prone to rust, apply paint or oil for protection ； Drain any liquid that has accumulated at the mechanical seal of the pump. 3.1.8 Inspection of key equipment: Every Thursday, the Maintenance Department organizes inspections of key equipment, requiring the participation of professionals from mechanical, electrical, and instrumentation fields to conduct inspections on the company’s key equipment and fill out relevant records. 3.1.9 Special maintenance for the units: The Maintenance Department organizes a special maintenance activity on every Monday, with participation from personnel involved in machinery, electrical systems, instrumentation, piping, and operation; the focus is on checking the readiness of the equipment, and a summary of the special maintenance work on these devices is prepared on a monthly basis. 3.1.10 Protection Measures for Critical Equipment
Sequence Number | Equipment Type | Equipment Tag Number | Protection Measures
1 | Special-care equipment | – | Oil circulation for rotation, addition of corrosion inhibitors
2 | Special-care equipment | – | Oil circulation for rotation
3 | Special-care equipment | – | Oil circulation for rotation with nitrogen filling
4 | Special-care equipment | – | Oil circulation for rotation with nitrogen filling
5 | Special-care equipment | – | Oil circulation for rotation
6 | Special-care equipment | – | Oil circulation for rotation, addition of corrosion inhibitors
7 | Special-care equipment | – | Rotation
8 | Special-care equipment | – | Oil circulation for rotation
9 | Special-care equipment | – | Oil circulation for rotation, addition of corrosion inhibitors
10 | Special-care equipment | – | Oil circulation for rotation
11 | Special-care equipment | – | Oil circulation for rotation
12 | Special-care equipment | – | Oil circulation for rotation
13 | Special-care equipment | – | Oil circulation for rotation
14 | Special-care equipment | – | Oil circulation for rotation
15 | Refrigeration unit | Rotation
16 | Reciprocating compressor | Oil circulation for rotation
17 | Centrifugal pumps, reciprocating pumps, screw pumps, gear pumps, vertical pumps, centrifugal fans, magnetic pumps | Rotation
18 | Agitators | Rotation
19 | Submersible pumps, submersible agitators | Extraction, lubrication, vertical placement
20 | Expander | Protection, air supply to bearings
21 | Equipment prone to oil leakage | Oil circulation for rotation
22 | Sulfur pumps, agitators | Removal
23 | Vertical acid pumps | Not removed; protected together with the system
24 | Management of spare equipment | Rust prevention, lubrication, rotation

3.2 Protection and Management of Process Equipment
3.2.1 Ensure proper shutdown, material removal, and purging procedures are followed. After this shutdown, pipeline cleaning and purging must meet the standards for major maintenance operations. During purging, the pipeline containing the material is first flushed with nitrogen and then with steam. After purging, all water must be completely removed; if necessary, it is flushed again with air or nitrogen to ensure that there are no residual materials or water inside the equipment and pipelines, thereby preventing localized corrosion. 3.2.2 Protection scheme for carbon steel equipment. The HL-911 type gas-phase protective agent for decommissioned equipment is used; this agent is a volatile gas-phase corrosion inhibitor that forms a protective film on the equipment surface. Within its shelf life, the metal surface of the equipment remains virtually free from corrosion and rusting. It can also remove existing rust layers and prevent corrosion beneath scale, with an effective corrosion inhibition efficiency of over 99%. We designed the deployment plan by subsystem and process; the deployment points were chosen at locations that are easy to disassemble and assemble, and the amount of medication used was calculated as the volume to be protected multiplied by the rate of 1 kg/m3, resulting in a total of 2.5 tons of medication to be used. 3.2.3 Protection scheme for sulfuric acid plant 3.2.3.1 Nitrogen protection scheme for the acid conversion and production areas: ① After the system has been purged, blind flanges are installed at the fan outlet, at the chimney, and on each tank used for acid production (see Blind Flange Table) to isolate the system from the outside world. Then nitrogen is filled in to provide slight positive pressure protection. ② A nitrogen pipeline (size 11/2 inch) is installed at the sight glass of the sulfur incineration furnace. ③ Nitrogen is pressurized daily, with a pressure of 2~5 KPa (G). ④Pressure control: Two pressure gauges are installed on-site; the control room is equipped with a remote pressure reproducer. 3.2.3.2 Protection plan for the acid tank area: ① Shut down system W-0801 and empty it. ②The vacuum breather valves of each tank, the silicone tanks, and the outlets of the vapor lines are covered and isolated with plastic sheeting. ③Remove, clean, and store in the warehouse; a blind flange is used here for isolation. 3.2.4 Arrangements for corrosion monitoring 3.2.4.1 Special thickness measurements shall be carried out on equipment internals that cannot be monitored during operation, pipelines of jacketed equipment, as well as high-temperature areas where thickness measurement errors are significant during operation. 3.2.4.2 Hang test pieces inside carbon steel equipment to monitor the anti-corrosion effect of the gas-phase protective agent and the corrosion status of the equipment. 3.2.4.3 Measure the thickness of equipment and pipelines every two months to check for corrosion during periods of downtime. 3.2.5 Protection of non-metallic equipment: The non-metallic equipment in our unit consists mainly of fiberglass-reinforced plastic equipment, which is not susceptible to corrosion by the atmosphere or water; it is sufficient to clean the materials thoroughly. After regular shutdowns, conduct internal and external inspections of the equipment, and promptly record any abnormal issues. During this shutdown inspection and assessment, corrosion was detected in some of the lining anti-corrosion coatings during operation; therefore, anti-corrosion treatment was carried out again: the surface of the fiberglass substrate was thoroughly sanded to achieve a smooth, rough, and dry surface — 2 layers of chopped fiber mat were applied — the surface was impregnated with resin — bubbles were removed by rolling firmly — the material hardened into a gel — burrs were removed — the above process was repeated 2 more times (2 additional layers of glass fiber mat were applied in the second round) — finally, 2 coats of resin coating with a thickness of 400 g/m2 were applied. 3.3 Electrical Equipment Maintenance and Operation Plan 3.3.1 Power Supply System Operation Plan during Downtime. 3.3.1.1 Ensure proper power supply for all electrical equipment, as well as adequate power for daily living needs. 3.3.1.2 Adjust the power supply method to reduce the power consumption of the power supply system itself, thereby minimizing energy use. Apply to the power supply department to shut down the two main transformers at the main station; the company’s electricity supply will be provided through the refinery interconnection line ； This way, the basic electricity fee can be avoided ； Turn off half of the company’s transformers to reduce losses associated with those transformers. 3.3.2 Power supply operation management during shutdown periods. 3.3.2.1 When power outage is required for electrical maintenance, an application must be submitted to the company’s dispatch department and the units that use electricity. 3.3.2.2 The operations for adjusting the power supply method must be carried out in strict accordance with the requirements of safety regulations. 3.3.2.3 The electrical workshop shall prepare an emergency operation plan for single-power supply across the entire plant, keep the external power supply lines in cold standby, and promptly restore power supply in case of emergencies in accordance with the plan. 3.3.2.4 The workshop shall establish the routine inspection tasks for the power supply system during shutdown periods, and these inspections shall be carried out on a daily basis as specified. 3.31.3 Protection plan during the shutdown of electrical equipment. 3.3.3.1 All substations shall be supplied with power normally, and inspections shall be carried out twice a day as required during normal operation to ensure the safe functioning of the equipment. 3.3.3.2 Some of the equipment in the production facility needs to be operated regularly in accordance with safety requirements; electricians turn the power on and off based on production demands to ensure the proper operation of the equipment. 3.3.3.3 Seal the motor bearing section, which is prone to water ingress, with grease to prevent the aging of the motor bearing lubricant. 3.3.3.4 Check that the transformer oil level is within the normal range, to prevent a drop in the oil level during winter shutdowns from affecting the transformer’s insulation ； Check that the oil seal of the transformer breather is in good condition and that the silica gel is effective, to prevent moisture from affecting the insulation properties of the transformer oil. 3.3.3.5 Ensure proper security measures for electrical equipment. Check that the doors and windows of each substation are in good condition, conducting inspections twice a day. 3.3.3.6 During shutdown periods, maintenance and renovation work on substations must be carried out in strict accordance with electrical safety regulations regarding power isolation and restoration, as well as the work order system. 3.3.3.7 Inspect facilities such as water pipes in the vicinity of the substation, and take protective measures in accordance with the company’s requirements for preventing freezing and condensation, so as to avoid ice damage and water leakage that could affect the operation of electrical equipment. 3.4 Maintenance and Operation Plan for Instrumentation Equipment: The instrumentation workshop focuses on providing protection in two areas: field instruments and DCS/PLC/large-scale unit controls. 3.4.1 Field Instruments 3.4.1.1 Establish a “Transmitter Out of Service Registration Form”, a “Control Valve Out of Service Registration Form”, and an “Instrument Inventory Registration Form” to ensure that each instrument has a record of when it was taken out of service, with responsibility assigned to specific individuals, thereby ensuring safe standby status for these instruments. Keep proper records of the stopped times and organize them in a clear and straightforward manner. 3.4.1.2 Based on the instrument heat tracing diagram and the distribution station diagram, use factory air for purging to remove any remaining water in the heat tracing lines, thereby preventing the pipelines from freezing. 3.4.1.3 Control valves and on/off valves: Disconnect the pipeline at the low point for venting and purging. Check whether the instrument air line contains water, drain the sediment tank of the pressure relief valve, and then close the instrument primary air valve. Medium-duty flange bolts; the valve stems of control valves are treated and lubricated to prevent corrosion ； 3.4.1.4 Differential pressure transmitter/pressure transmitter: Close the primary sampling valve, open the positive and negative vent valves; after cleaning the pressure guiding tubes, disconnect them at the five-valve assembly. Clean the instrument itself using an instrument-specific blower, and for critical parts of the instrument, inject ethylene glycol as an antifreeze using a pressure pump or spray bottle ； 3.4.1.5 Double flange for flanged transmitters: Close the primary valve, remove the flanges to drain the contents, take the instrument back for calibration, and then reinstall it. Perform zero-point adjustment for the double flanges; once the primary valve is opened again at the next start-up, the device can be put into operation. 3.4.1.6 Float level gauges and level switches: These are primarily used for external floats; they are purged together with the process equipment, the upper and lower vent valves are opened, while the positive and negative pressure tapping valves as well as the vents are closed. Top screw plug. 3.4.1.7 pH meters and other analytical instruments: A tank has been set up in the workshop to keep the removed pH meters and other analytical instruments submerged in water, thereby enabling unified management ； For analytical instruments that cannot or need not be disassembled, the measuring elements and sampling chamber are cleaned on-site, after which the instrument is taken out of service and sealed for maintenance. 3.4.1.8 Mass flow meter: The flow tube was purged with hot water or steam during shutdown, and finally purged and flushed with instrument air or nitrogen for storage. 3.4.1.9 Flow tubes for rotameters/orifice plate flow meters/electromagnetic flow meters/vortex flow meters: Purged along with the process pipeline. 3.4.1.10 Ensure that the detectors for flammable gases and toxic/hazardous gases are in proper operation, and strengthen routine inspections. 3.4.2 DCS/PLC/large-scale unit control: 3.4.2.1 Ensure proper software backups for DCS/PLC and large-scale unit control systems; keep two copies of the software backups, one in the workshop and another in the team area, and also create a final BACKUP on the hard drive of the engineer station ； 3.4.2.2 Once all maintenance work on the equipment has been completed, cut off power to those control systems for which it is possible to do so; seal the cabinets that have had their power turned off ； 3.4.2.3 Disconnect all terminals connected to the site and substation MCCs, and keep detailed records ； 3.4.2.4 All operations and changes during the shutdown period must be recorded in detail and comprehensively, to be preserved as original evidence in preparation for power restoration upon resuming operation. 3.4.2.5 After the shutdown, unsafe factors in various control rooms were inspected; all doors and windows were checked to ensure they were in good condition and locked. Special attention was paid to preventing rats and other small animals from entering, and daily inspections of the main control rooms were carried out to ensure the safety of the DCS equipment.