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Equipment preventive maintenance primarily aims to avoid failures through planned maintenance methods, including regular inspections and repairs. Generally, preventive maintenance requires the establishment of annual maintenance or repair plans. The **Guiding Opinions of the State Administration of Work Safety on Strengthening the Safety Management of Chemical Processes** (An Jian Zong Guan San [2013] No. 88) specifies, in regard to the \"safe operation management of equipment,\" the requirement to \"carry out preventive maintenance on equipment.\" The emphasis on carrying out preventive maintenance stems from the fact that monitoring and routine inspections during equipment operation cannot uncover all potential issues with the equipment. For example, defects such as wear and cracks in the components of rotating equipment, as well as problems like aging or failure of gaskets in stationary equipment, can only be detected through planned maintenance and inspections. Secondly, wear-prone parts of rotating equipment and gaskets of stationary equipment have a service life, and they should be inspected and replaced before that life expires. Currently, many hazardous chemicals companies fail to carry out proper preventive maintenance on their equipment, or they do not conduct such maintenance in a systematic manner. The reasons for this include issues related to awareness and understanding, as well as technical factors. At the technical level, it’s unclear how to proceed in order to truly avoid both equipment deterioration and over-maintenance of the equipment. Recently, the author went to a petrochemical enterprise in Shandong to provide standardization guidance and found that their practices are worth recommending; they are introduced below. The specific practices of this company can be summarized in three main points. First, different maintenance strategies are developed for various devices, resulting in the establishment of \"Equipment Maintenance Technical Standards,\" which define relatively scientific maintenance cycles for these devices ； Secondly, when formulating the annual maintenance plan, the \"Equipment Maintenance Technical Standards\" should be used as an important reference to ensure the effective implementation of preventive maintenance for the equipment ； Third, requirements are set to ensure the effective implementation of the maintenance plan. In summary, the company has scientifically implemented preventive maintenance for its equipment. I. Formulating the \"Equipment Maintenance Technical Standards\": A key reason for the poor implementation of preventive equipment maintenance is the inaccurate and unscientific determination of maintenance intervals, which often leads to neglect in maintenance tasks. In light of its own specific circumstances, this company first established practical \"Equipment Maintenance Technical Standards\" (maintenance strategies) based on the following maintenance principles. Companies follow the principle of equipment classification, formulating different maintenance strategies for equipment at various levels ； For equipment whose failures cannot be predicted through trend forecasting and quantitative analysis, failure prevention is mainly achieved through planned maintenance methods, including regular inspections and repairs, which are collectively referred to as preventive maintenance strategies. It is characterized by repairs or replacements being carried out in advance, rather than because the usage period of a certain component in the facility has expired, but rather due to the fact that its service life has not yet ended. Preventive maintenance requires the establishment of an annual maintenance or repair plan ； For devices that can predict the occurrence of failures based on trend data from their operation along with corresponding quantitative diagnostic techniques, predictive maintenance strategies are employed. It also stipulates that \"during the operation of the device, no maintenance or internal calibration work may be carried out until the conditions for such tasks are met; major repairs to the device are not permitted at this time.\" ； During equipment maintenance (major overhauls of the equipment), only those maintenance tasks that cannot be carried out on a daily basis are performed. ”The \"Equipment Maintenance Technical Standards\" cover rotating equipment, stationary equipment, electrical equipment, and instrumentation equipment. Taking moving equipment as an example, the \"principles for the maintenance of moving equipment\" mainly include the following: the modification and upgrading of components involved in the overall maintenance of moving equipment or in technical renovation projects falls under the category of maintenance ； The maintenance of movable equipment with spare units should be included in the regular maintenance plan, and not included in the major repair plan (plant overhaul plan); in special cases, approval from the Equipment Health Management Department is required ； Class A equipment is subject to reliability management; the local workshops develop annual plans, and by using the FMEA tool and conducting analyses of potential failure modes and their consequences, they establish actionable measures to improve the reliability of the equipment ； The maintenance records for the operation support workshop must be filled out completely as required for future reference. Regarding the basis for compiling the \"Technical Standards for Equipment Maintenance\" for mechanical equipment, the author consulted Engineer Du, the person in charge of mechanical equipment at the company. Mr. Du explained that currently, the basis for compilation mainly relies on the regulations for petrochemical equipment and the equipment manuals provided by specific manufacturers, taking into account the historical operating conditions of the equipment as well as the actual replacement frequency. In addition, the replacement cycles of various vulnerable components are also considered (attempting to keep them synchronized where possible). In addition, companies are currently organizing equipment managers from various workshops to conduct FMEA (Failure Mode and Effects Analysis) regarding the operational risks of rotating equipment. This year, 209 pieces of equipment are scheduled to be analyzed, including 185 key pumps and 12 centrifuge units. Next, the \"Equipment Maintenance Technical Standards\" will be further refined by taking into account the results of FMEA (Failure Mode and Effects Analysis), in order to make them more scientific and accurate. Conventional equipment inspection and maintenance procedures are general in nature, but they do not take into account the specific conditions of a company’s equipment; the \"Equipment Maintenance Technical Standards\" established by companies are more scientific and reasonable than ordinary maintenance procedures. Currently, the maintenance strategies formulated by many companies serve the same purpose. II. Formulating annual maintenance plans At present, a direct manifestation of the fact that many hazardous chemicals companies fail to carry out preventive maintenance effectively is their failure to develop preventive maintenance plans for their equipment in accordance with the equipment maintenance procedures (maintenance strategies). Let’s take a look at what this company does. To ensure that equipment performance always meets design specifications and that its condition remains within safe limits, thereby satisfying production requirements and maintaining product quality, and to avoid safety risks and economic losses resulting from equipment failures, the enterprise’s equipment department requires each workshop to conduct assessments of the equipment’s condition and operational performance, and to develop annual inspection, testing, and preventive maintenance plans in accordance with the principles of hierarchical equipment management. 1. Principles for formulating the annual maintenance plan: (1) Meeting the requirements of laws and regulations regarding regular inspection and testing items ； (2) Comply with the periodic inspection, testing, and regular maintenance tasks recommended by the equipment manufacturer ； (3) Regular inspection, testing, and maintenance tasks required due to the periodic decline in equipment performance to the point where it can no longer meet economic and production requirements ； (4) Includes corrosion inspection plan ； (5) Equipment-based scheduled work plan ； (6) Maintenance and repair plan formulated based on previous inspection and testing results ； (7) In accordance with the Equipment Maintenance Technical Standards. 2. Requirements for formulating the annual maintenance plan: (1) It shall be organized by the local workshop, with the participation of professionals from various fields such as mechanical, electrical, and instrumentation in the operation support team in formulating it ； (2) Break down the annual maintenance plan into monthly tasks ； (3) The relevant plans shall be reviewed by the heads of various workshops and the supervisors of each specialty, approved in writing by the head of the Equipment Health Management Department, and then implemented after being recorded in the Equipment Health Management Center; this process must be completed by December 25th of the same year ； (4) The plan shall be formulated in strict accordance with the company’s template and content format requirements, with particular attention paid to specifying: the OS system (enterprise management system) code, maintenance type, and maintenance contents. In terms of the timeline, sorting and compiling data will begin in September, while discussions, finalization, and distribution will take place in November and December. When formulating the annual maintenance plan, the information regarding the equipment’s previous maintenance history and actual operating time are the most crucial basic data. On this topic, Du, the supervisor in charge of mechanical equipment at the company, explained to the author that, on one hand, emphasis is placed on digitizing the records related to equipment maintenance; at the same time, efforts are made to ensure that maintenance work orders are automatically linked to the relevant maintenance records. In carrying out these tasks, full use is made of the equipment’s interconnectivity and intelligent management platforms ； On the other hand, based on current levels, work orders, spare parts inventory, etc., device \"profiles\" are developed, with particular emphasis on utilizing the data on device operation currents in the DCS to calculate the operating time (in days) of spare devices. III. Implementation of the maintenance plan: Based on the annual maintenance plan, the enterprise ultimately relies on monthly maintenance plans to ensure that preventive maintenance tasks are carried out. When implementing the company’s annual maintenance plan, pay attention to the following matters. (1) After the annual maintenance plan is imported into the equipment health management system, monthly maintenance plans generate maintenance work orders based on the annual plan. For the temporary plan work orders of the next month, the online submission process on the information platform must be completed by the 25th of that month. Mechanical, electrical, and instrumentation components must be reviewed by the supervisors of the respective departments in the operation and maintenance workshop, while static equipment needs to be examined by the department heads of that workshop. Only after approval from the supervisors of the Equipment Health and Operation Department can they be incorporated into the system. Tickets generated during the remaining time are handled as unplanned maintenance. To initiate a temporary work order, it is necessary to provide detailed explanations for the reasons behind the maintenance effort and the specifics of the maintenance work; such cases are included in the assessment of unplanned maintenance, and efforts are made to analyze the causes of these unplanned repairs. (2) If the equipment inspection, testing, and preventive maintenance work plans cannot be carried out on schedule, the relevant workshop must submit an application for delaying and modifying the planned maintenance work order, and continue to monitor the subsequent handling process until the maintenance is completed. The application for a delay in the maintenance schedule must specify the planned maintenance date, the requested date for the delay, the previous maintenance date, the reasons for the delay and the change, the criticality level of the equipment, as well as the risks associated with failure to carry out maintenance on time and the measures taken to address these risks. Such applications must be submitted to the supervisors of relevant departments in the Equipment Health Management Department for approval. In principle, delays caused by force majeure circumstances may exempt the equipment from undergoing maintenance; all other cases are included in the assessment of the maintenance schedule compliance rate. (3) Planned maintenance is carried out strictly in accordance with work orders, adhering to the principle of \"starting on the same day, recording on the same day, completing on the same day, and verifying on the same day\"; maintenance data is recorded in real time to ensure that it can be analyzed and summarized regularly. Any instances of fraud such as early submission, non-submission, late submission, or supplementary submission of work orders will result in strict evaluation for that month. (4) Any abnormalities or defects identified during the implementation of planned maintenance should be brought under control, and a DingTalk form titled \"SH-JCSS-024 Equipment Exception Analysis Report Approval Form\" should be used to document and analyze them. (5) Temporarily added work order attachments must follow the OS system (Enterprise Management System) template attachments. At the same time, the company also released a \"Template for Applying for Delayed Maintenance Work Orders.\" During operation, the company also analyzed the performance of over a thousand reciprocating compressors and found that 30% of the failures were caused by poor lubrication. Since the existing oil injection systems were unable to monitor or control the amount of oil injected, the company collaborated with a specialized manufacturer to develop and install China’s first cylinder lubrication system based on injectors and controlled by PLCs in two new hydrogenation units. This system enables real-time monitoring and precise control of the oil injection volume at each point, thereby enhancing the safety, reliability, and flexibility of the lubrication system and preventing abnormal damage to the compressors due to lubrication issues. Next, taking into account the current status of their existing equipment, the company formulated a plan to further enhance the safe and stable operation of these devices. This includes implementing load warning systems, collaborating with electrical specialists, and accessing data on the operating loads of key devices in order to enable load warnings. Based on an analysis of the devices’ operating conditions, the company determines their operational lifespan ； Another example is the health rating, which uses various dimensional parameters and indicators to assess the health of a device, thereby enabling the visualization of its operational health status. IV. It is recommended that, regarding preventive maintenance of equipment, the most important thing is to have a proper understanding. Firstly, from a technical perspective, it should be understood that planned preventive maintenance is not synonymous with over-maintenance; rather, it is essential to ensure that maintenance is not neglected and to keep the equipment running safely ； Secondly, at the management level, the equipment management system must effectively oversee the entire life cycle of equipment, rather than functioning merely as a \"maintenance department\" that waits for things to break before fixing them. Given the importance of preventive equipment maintenance, the author also suggests that hazardous chemicals companies should make careful decisions when extending the overhaul cycle of their facilities. They should seek input from the equipment management department and thoroughly consider whether the equipment operating in a single series – including pumps, vessels (especially heat exchange equipment), and safety accessories – is capable of functioning safely and stably throughout one overhaul cycle. In other words, the overhaul cycle for a facility should be determined based on the safe and stable operation period of each piece of equipment within that facility.