Perancangan Strategi Inspeksi Berbasis Risiko Pada Reaktor Urea DC 101 Menggunakan API 581 dan Validasi Fitness For Service

Ridandi, Diavanka Triayu Lestari (2026) Perancangan Strategi Inspeksi Berbasis Risiko Pada Reaktor Urea DC 101 Menggunakan API 581 dan Validasi Fitness For Service. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Reaktor urea DC-101 (UDC-101) di PT X merupakan peralatan kritikal yang beroperasi pada tekanan tinggi hingga 155 kg/cm² dan temperatur sekitar 182°C, serta berada dalam lingkungan proses yang sangat korosif akibat keberadaan NH₃, CO₂, dan larutan karbamat. Kondisi tersebut menyebabkan terjadinya penipisan dinding (thinning) pada lining internal reaktor akibat korosi umum, yang berpotensi meningkatkan risiko kebocoran dan kegagalan operasi. Penelitian ini bertujuan untuk merancang strategi inspeksi berbasis risiko menggunakan metode Risk-Based Inspection (RBI) mengacu pada API 581 serta melakukan validasi kelayakan operasi reaktor melalui metode Fitness-For-Service (FFS) Level 1 berdasarkan API 579. Analisis dilakukan pada dua kelompok segmen lining, yaitu segmen 4–5 sebagai pelat lama menggunakan data ketebalan periode 2007–2021, dan segmen 1–3 sebagai pelat baru pasca relining menggunakan data periode 2022–2024. Hasil analisis menunjukkan bahwa segmen 1–3 memiliki laju korosi relatif rendah, berkisar antara 0,02–0,035 mm/tahun, dengan nilai probabilitas kegagalan akibat thinning (Pf_thin) pada orde 10⁻⁶ sehingga dikategorikan pada tingkat risiko menengah (1E). Sebaliknya, segmen 4–5 menunjukkan laju korosi yang lebih tinggi, yaitu 0,174–0,212 mm/tahun, dengan nilai Pf_thin sebesar 0,126–0,188 dan tingkat risiko tinggi (3E–4E), serta memiliki umur sisa terpendek yaitu sekitar 1,5–4,1 tahun. Evaluasi Fitness-For-Service menggunakan API 579 Level 1 menunjukkan bahwa seluruh segmen masih memenuhi kriteria kelayakan operasi, meskipun segmen 4 memerlukan perhatian lebih lanjut melalui evaluasi Remaining Strength Factor (RSF). Berdasarkan hasil tersebut, strategi inspeksi yang diusulkan memprioritaskan segmen 4–5 dengan interval inspeksi ≤1–2 tahun, sementara segmen 1–3 cukup dilakukan pemantauan berkala. Pendekatan ini diharapkan mampu meningkatkan keandalan, keselamatan, dan efisiensi pengelolaan integritas reaktor urea.
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Urea reactor DC-101 (UDC-101) at PT X is a critical unit in the urea synthesis process operating at high pressure up to 155 kg/cm² and temperature of approximately 182°C. The aggressive process environment containing NH₃, CO₂, and ammonium carbamate solution promotes corrosion, leading to wall thinning of the internal lining. This degradation increases the risk of leakage, potentially affecting operational safety, reliability, and economic performance. This study aims to develop a risk-based inspection strategy using the Risk-Based Inspection (RBI) methodology in accordance with API 581 and to validate the operational fitness of the reactor using Fitness-For-Service (FFS) Level 1 assessment based on API 579. The analysis was conducted on two groups of lining segments: segments 4–5 representing the old plates evaluated using thickness data from 2007–2021, and segments 1–3 representing relined plates assessed using data from 2022–2024. The results indicate that segments 1–3 exhibit relatively low corrosion rates ranging from 0.02 to 0.035 mm/year, with thinning probability of failure (Pf_thin) on the order of 10⁻⁶, corresponding to a medium risk level (1E). In contrast, segments 4–5 show significantly higher corrosion rates of 0.174–0.212 mm/year, Pf_thin values of 0.126–0.188, and high risk levels (3E–4E), with the shortest remaining life estimated at 1.5–4.1 years. Fitness-For-Service evaluation confirms that all segments remain acceptable for operation; however, segment 4 requires additional attention through Remaining Strength Factor (RSF) assessment. Based on these findings, the proposed inspection strategy prioritizes segments 4–5 with inspection intervals of ≤1–2 years, while segments 1–3 require periodic monitoring. This integrated RBI–FFS approach is expected to enhance reactor integrity management, operational safety, and inspection efficiency.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Risk-Based Inspection, Urea Reactor, API 581, Risk-Based Inspection, Reaktor Urea, API 581
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA418.75 Corrosion-resistant materials T Technology > TS Manufactures > TS156 Quality Control. QFD. Taguchi methods (Quality control) T Technology > TS Manufactures > TS173 Reliability of industrial products
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Material & Metallurgical Engineering > 28201-(S1) Undergraduate Thesis
Depositing User:	Diavanka Triayu Lestari Ridandi
Date Deposited:	02 Jul 2026 07:14
Last Modified:	02 Jul 2026 07:14
URI:	http://repository.its.ac.id/id/eprint/134211

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