Analisis Kegagalan Compressor 35k6 Pada Compressed Air System Menggunakan Metode Fault Tree Analysis Pada Industri LNG Kalimantan

Alfiansyah, Muhammad Difi Alfiansyah (2026) Analisis Kegagalan Compressor 35k6 Pada Compressed Air System Menggunakan Metode Fault Tree Analysis Pada Industri LNG Kalimantan. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Keandalan sistem udara bertekanan (compressed air system) merupakan faktor penting dalam mendukung kontinuitas operasi kilang LNG karena berfungsi sebagai pemasok instrument air dan service air. Berdasarkan data historis work order periode 2012–2024, Air Compressor 35-K-6 menunjukkan frekuensi corrective maintenance dan breakdown maintenance yang tinggi sehingga diperlukan analisis untuk mengidentifikasi penyebab kegagalannya. Penelitian ini bertujuan mengidentifikasi basic event penyebab Compressor 35-K-6 System Failure menggunakan metode Fault Tree Analysis (FTA) secara kualitatif dan kuantitatif serta memvalidasi failure mode dominan melalui analisis data vibrasi dan simulasi harmonic response. Analisis kuantitatif dilakukan dengan menghitung failure rate, confidence interval, dan Probability of Failure (PoF) berdasarkan data historis pemeliharaan. Hasil analisis menunjukkan bahwa struktur FTA menghasilkan 22 Minimal Cut Sets (MCS) yang masing-masing terdiri dari satu basic event. Probabilitas kegagalan top event sebesar 0,998303584 per tahun, dengan basic event yang memiliki kontribusi terbesar adalah Excessive Vibration sebesar 0,536330312. Analisis spektrum getaran (Fast Fourier Transform/FFT) menunjukkan dominasi komponen frekuensi 1×RPM yang mengindikasikan rotor unbalance. Hasil simulasi harmonic response menunjukkan bahwa kondisi aktual menghasilkan amplitudo getaran yang melebihi kondisi permissible unbalance, sehingga memvalidasi rotor unbalance sebagai penyebab Excessive Vibration. Berdasarkan hasil tersebut, disusun rekomendasi aktivitas pemeliharaan menggunakan pendekatan Reliability Centered Maintenance (RCM II) untuk mendukung peningkatan keandalan Air Compressor 35-K-6.
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The reliability of the compressed air system is a critical factor in supporting the continuous operation of an LNG plant, as it serves as the primary source of instrument air and service air. Based on maintenance work order records from 2012 to 2024, Air Compressor 35-K-6 experienced frequent corrective and breakdown maintenance, indicating the need for a comprehensive failure analysis. This study aims to identify the basic events contributing to Compressor 35-K-6 System Failure using qualitative and quantitative Fault Tree Analysis (FTA) and to validate the dominant failure mode through vibration data analysis and harmonic response simulation. The quantitative analysis was conducted by calculating the failure rate, confidence interval, and Probability of Failure (PoF) using historical maintenance data. The qualitative analysis produced 22 Minimal Cut Sets (MCSs), each consisting of a single basic event due to the Fault Tree structure being composed entirely of OR gates. The quantitative results showed that the top event had a Probability of Failure (PoF) of 0.998303584 per year, while Excessive Vibration was identified as the dominant basic event with a PoF of 0.536330312. Fast Fourier Transform (FFT) analysis revealed a dominant 1×RPM frequency component, indicating rotor unbalance. Furthermore, harmonic response simulation demonstrated that the vibration amplitude under the existing operating condition exceeded the amplitude corresponding to the permissible unbalance condition, thereby validating rotor unbalance as the primary cause of excessive vibration. Based on these findings, maintenance recommendations were developed using the Reliability Centered Maintenance (RCM II) approach to improve the reliability of Air Compressor 35-K-6.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Air Compressor , Fault Tree Analysis, Harmonic Response , Reliability Centered Maintenance, Rotor Unbalance. Air Compressor , Fault Tree Analysis, Harmonic Response , Reliability Centered Maintenance, Rotor Unbalance.
Subjects:	T Technology > TJ Mechanical engineering and machinery > TJ990 Compressors T Technology > TS Manufactures > TS174 Maintainability (Engineering) . Reliability (Engineering)
Divisions:	Faculty of Vocational > Mechanical Industrial Engineering (D4)
Depositing User:	MUHAMMAD DIFI ALFIANSYAH
Date Deposited:	31 Jul 2026 07:45
Last Modified:	31 Jul 2026 07:45
URI:	http://repository.its.ac.id/id/eprint/139191

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