【Weekly Topic】Discussion on decommissioning equipment (second week of July)
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This post was last edited by zxf760718 on 2015-7-6 08:35. As the market remains weak and the economic downturn continues, some manufacturing enterprises have gone bankrupt under severe economic pressure, while others continue to operate at a partial capacity. Faced with such circumstances, the pressure on equipment workers is also increasing, mainly due to the maintenance issues related to the decommissioned equipment. Some equipment, as specified in their manuals, only requires appropriate protection when it is not in use – such as nitrogen filling for protection. However, many manuals recommend removing the oil seals as a form of protection for equipment that will be left unused for an extended period. Since it’s unclear when the economic situation will improve, managing equipment with removed oil seals becomes rather complicated. This leads to this week’s topic: This week’s topic: Does your company have any equipment that is not in use? What kind of protection is used for devices that are taken out of service on a long-term basis? How are devices that require disassembled protection managed? Everyone is welcome to engage in in-depth discussions! 【Collection of Essential Knowledge in the Mechanical Field】http://bbs.hcbbs.com/thread-1389197-1-1.html Solicitation for weekly topics and daily questions (prizes for participation) http://bbs.hcbbs.com/thread-1373282-1-1.html Summary post of weekly topics: http://bbs.hcbbs.com/thread-1404940-1-1.html
Moving equipment: 1. To prevent deformation and sticking of the shafting in moving equipment, it is necessary to turn them regularly. For large units, this should be done once a month for no less than half an hour each time; for small pumps, it should be done once a month, turning them 180 degrees each time. 2. Large units should be operated with oil once a month; the operation time should be no less than 6 hours in winter, no less than 2 hours in summer, and no less than 3 hours in spring and autumn. 3. All moving parts of the lifting equipment should be inspected once a year, with maintenance carried out as appropriate. Electrical and instrumentation equipment: Electrical cabinets and instrumentation cabinets are cleaned once a year, while UPS units are charged once per quarter. During winter, necessary anti-freezing measures should be taken to prevent damage to the power supply due to freezing. Equipment exterior: 1. The shaft shoulders of the pumps, the exposed valve stems, and the steel cables of lifting equipment should be coated with grease once a year. When greasing the valve stem, first ensure the valve is in the fully open position; after greasing the threaded part of the valve stem, then close the valve completely. After lubricating the steel wire rope and valve stem, wrap them promptly with thick plastic film. 2. The electrical components of outdoor lifting equipment, the valve heads of various other types of valves (such as electronically controlled valves and pneumatically controlled valves), the on-site control panels, the surface-mounted instruments, the machine body, and the associated motors are all covered with thick plastic film. 3. Based on the corrosion condition of the equipment and the outer surfaces of steel components, take feasible measures for anti-corrosion treatment. 4. Move key, precise, and valuable electrical instruments back to the warehouse for secure storage. 5. The floor, equipment surfaces (or covers), and the factory premises should be cleaned weekly. Ensure the floor is free of debris, the surfaces of equipment are mostly free of dust and oil stains, the factory premises are clean and tidy, items are arranged neatly, and waste is collected promptly. Maintenance of pneumatic diaphragm pumps: No lubricant is required before or during use of the pump. However, when reassembling after disassembly, appropriate lubricant should be applied between the central shaft and the copper sleeve; a layer of lubricant can also be applied on the inner side of the outer pressure plate when installing the diaphragm pressure plate. This helps with proper alignment and makes sealing as well as disassembly easier. When removing the valve spool and sleeve of the main air valve, it is absolutely forbidden to use hard tools in contact with them, as the fit between the valve spool and sleeve is extremely precise. A small amount of grease should also be applied when installing the gas valve and guide valve to ensure proper lubrication. Before inserting the valve into the valve housing, apply a small amount of grease to the O-ring outside the housing, and then push it in by hand; do not strike it. Before installing the pump, clean and dry the inside of all components (the air intake area), and check that all seals are in good condition (referring mainly to the U-shaped seals on the shaft) ； O-ring on the ejector pin ； O-ring on the pilot spool ； Compaction and sealing of the inner and outer pressure plates of the diaphragm ； Compaction and sealing of inner and outer chambers ； Ball seat ball valve sealing ； For the pilot valve, intake cover, and air valve gasket sealing, it is also possible to install them while checking and applying grease at the same time.
The second floor covers everything in detail; additionally, it’s important to keep good maintenance records. When it is time to apply blind flanges to the system components, such flanges should be installed, and a list of these blind flanges should be created. Ensure proper fire and theft prevention measures; it’s best not to turn off the fire alarm system, and so on
What was said upstairs is quite comprehensive. Additionally, in summer, the main things to check are static electricity grounding, lightning and static protection measures, as well as flood prevention
Before 1996, prolonged shutdowns involved pressure relief, catalyst deactivation, inert gas purging, installation of blind flanges, along with proper recording and on-site labeling. There were also routine inspections and overhauls of the equipment, as well as daily rotation of the machinery. Later on, this practice was discontinued; by not replacing the catalyst and instead simply relieving pressure in the tower and installing blind flanges, costs associated with heating and reduction processes could be saved. Do the rest as needed.
Everything has been thoroughly explained upstairs; we just remove it, clean it thoroughly, keep records of it, and then store it in a sealed condition.
Does your company have any equipment that is not in use? Device shutdowns fall into three categories: temporary (for reversal use, maintenance, or technical upgrades), long-term disuse, and irregular (due to operational needs). We have devices that are temporarily disabled. What kind of protection is used for devices that are taken out of service on a long-term basis? Static equipment: Sealed after being purged with nitrogen. Moving equipment: Left stationary after maintenance. How are devices that require disassembled protection managed? The removed parts are coated with rust preventive oil, then wrapped in plastic film and stored.
For moving equipment, fill the oil regularly and run it without a load for a short period each week； For static equipment, after shutdown, clean it thoroughly and fill it with nitrogen to maintain pressure
For moving equipment, perform regular turning and oiling； For static equipment, after shutdown, clean it thoroughly and fill it with nitrogen to maintain pressure
The methods are mostly similar; the key lies in whether they can actually be implemented and whether there are any supervision and inspection measures in place.