Reliability Improvement Analysis of Pump Liquid O2 P-805A USING THE FMECA, MTBF, and MTTR Approaches To Reduce Downtime at PT. Gresik Gases Indonesia

Abstract

Pump Liquid O2 P-805A is a critical equipment in the liquid oxygen production process at PT. Gresik Gases Indonesia, functioning to transfer liquid oxygen from tank T-80C to T-80D. Recurring failures, especially in the mechanical seal component, have caused downtime that disrupts production continuity. This study aims to determine the pump's critical component and evaluate its reliability level by integrating three methods sequentially: Failure Mode Effect and Criticality Analysis (FMECA), Mean Time Between Failure (MTBF), and Mean Time To Repair (MTTR). Data were obtained from the pump's failure and repair history during the 2022-2026 period, consisting of eight failure events. The FMECA stage was used to identify failure modes, calculate the Risk Priority Number (RPN), and classify the risk level through a risk matrix, while the MTBF and MTTR stages were used to measure the reliability and maintainability of the identified critical component. The FMECA results show that among three identified failure modes, mechanical seal leak/leakage has the highest RPN of 512 and is classified as “High” risk, making it the critical component. Further calculation for this critical component results in an MTBF of 2,702.4 hours, an MTTR of 18.67 hours, and an availability of 99.31%. As a comparison, the pump's overall reliability (all failure modes) results in an MTBF of 5,033.14 hours, an MTTR of 15.5 hours, and an availability of 99.69%. The results of this FMECA-MTBF-MTTR integration form the basis for scheduling mechanical seal preventive maintenance at an interval of 2,000-2,500 operating hours to reduce downtime and continuously improve pump reliability.