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Recently, the Third Refining Unit of Guangdong Petrochemical successfully overcame the persistent problem of excessive vibration in the motor of P-0102B, the feed pump for the hydrocracking unit, through independent technical efforts. The vibration level on the non-drive side was reduced from 118 μm to 38 μm, with all parameters meeting or exceeding the manufacturer’s requirements. This eliminated potential operational risks and saved nearly one million yuan in costs associated with equipment replacement. The feed pump is a core and critical equipment in hydrocracking units, and the problem of excessive motor vibration has existed for a long time. Since June 2023, the vibration level at the non-drive endⅥ-7105BY of this pump motor has frequently exceeded the specified limits and fluctuated, posing a high risk of bearing burnout and rotor scoring. Despite multiple repairs and efforts to get the manufacturer to address the issue, and even facing difficult choices such as having to send the equipment back to the factory for 20 days of repairs without a backup pump available and the high cost of replacing it at a cost of millions, the problem was never fully resolved. “The problem is at the site; solve it right there! ”In February this year, Gao Renpeng, the manager of Refining Department 3, took the lead in forming a special task force to conduct a comprehensive inspection of the equipment. By analyzing operation and maintenance data and taking into account the monitoring results from Lanzhou Weida, the technical team accurately identified the root cause: wear of the main motor shaft bearings and excessive original installation clearance. Upon disassembly inspection, it was found that the babbitt layer of the lower bearing shell on the non-drive side had suffered fatigue spalling, and the clearances of the bearings at both ends exceeded the specified upper limit of 0.25 mm. The task force innovatively adopted a \"precise gap regulation\" approach, adjusting the bearing shell gap from its upper limit to near the lower limit, while simultaneously replacing the damaged bearing shells. Through the joint efforts of all involved parties and the strong support of the Maintenance and Operation Department, after multiple measurements to adjust the bearing clearance, as well as several trial runs of the motor alone and under load, the shaft vibration levels at both ends of the feed pump motor were significantly reduced during its final trial run. These levels met all the requirements set by the manufacturer and relevant regulations, enabling the motor to be in good condition for use. “This is equivalent to providing double protection for high-risk equipment. ”Sun Zhongxin, an equipment engineer at Refining Department 3, said that this independent effort not only avoided the risk of operating without backup pumps but also established technical standards for precise assembly, providing a new approach for the maintenance of similar equipment. According to statistics, this solution reduces the project duration by 16 days compared to returning the equipment to the factory for maintenance. (Zhou Shiwen)