Abstract: As a key equipment for lube oil filtration in large diesel units of offshore facilities， the main function of the lube oil separator is to separate the lube oil used in the fuel oil unit. Through centrifugal separation， the impurities and moisture inside the lube oil are removed， ensuring the quality of the lube oil and avoiding damage to the operation of the fuel oil unit due to lube oil deterioration. At the same time， the service life of the equipment is improved， the frequency of lube oil replacement is reduced， and the economic benefits are improved. In order to reduce the frequent shutdown of the lube oil separator due to speed reduced during slag discharge and low outlet pressure， the cause of the fault is analyzed and a solution is proposed， providing a reference basis for equipment fault handling.

Key words: lube oil separator, reduced speed during slag discharge, low outlet pressure, fault analysis