Analisa kegagalan u-tube economizer SA210- A1 B-1102 di pabrik PT. Petrokimia Gresik

Tajalla, Gusti Umindya Nur (2015) Analisa kegagalan u-tube economizer SA210- A1 B-1102 di pabrik PT. Petrokimia Gresik. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Economizer merupakan komponen penting dalam meningkatkan efisiensi perpindahan panas hingga 4-6% di dalam sistem boiler pipa air. Kegagalan pada pipa u-tube economizer SA210-A1 Boiler-1102 PT. Petrokimia terjadi pada lengkungan dalam pipa. Untuk menanggulangi hal yang serupa, analisa kegagalan pada u-tube economizer ini perlu dilakukan. Beberapa pengujian dilakukan untuk mendukung hasil analisa. Secara visual, terdapat branching di permukaan water-side tube, tidak terdapat lateral corrosion pada perambatan crack, dan morfologi crack yang lebar. Hasil OES menunjukkan bahwa sample material memenuhi standar ASTM A210-A1. Namun perhitungan persentase regangan menunjukkan 33,33%,. Persentase in melebihi standar yang telah ditentukan, yaitu 30%. Selain itu terdapat residual stress di dalam tube akibat proses strain hardening. pH feedwater boiler sempat mengalami penurunan beberapa kali, walaupun tidak begitu signifikan, namun dapat melarutkan lapisan pelindung magnetite [Fe3O4], sehingga reaksi antara Fe dan O mempercepat perambatan crack. Ketiga faktor tersebut merujuk pada stress corrosion cracking (SCC) yang memiliki morfologi campuran intergranular-transgranular (IG-TG). ============================================================================================== Economizer is an important component for improving the efficiency of heat transfer up to 4-6% inside the boiler systems. The failure of u-tube economizer SA210-A1 pipe of Boiler-1102 of PT. Petrokimia happened on the curve of the pipe. To anticipate it from re-occuring, a failure analysis on the u-tube economizer is needed. A few tests were conducted to support the analysis results. Visually, branching was found on the surface of water-side tube, there were no lateral corrosion on crack propagation area, and the wide crack morphology. OES results showed that the sample material had fulfilled the ASTM A210 standard. However, the calculation on strain percentages was resulting in 33,33%. This percentages was above the allowable strain in the standard, which is 30%. Other than that, there was residual stress inside the tube as the aftermath of strain hardening. The boiler’s pH feedwater had dropped a few times even though it wasnn’t to significant, it still could dissolve the magnetite protective layer [Fe3O4], so that reaction between Fe and O exacerbate the crack propagation. These three factors referred to stress corrosion cracking (SCC) that have mix intergranular-transgranular (IG-TG) morphology.

Item Type: Thesis (Undergraduate)
Additional Information: RSMt 620.112 Taj a
Uncontrolled Keywords: u-tube; economizer; kebocoran; SCC; IG-TG
Subjects: T Technology > TJ Mechanical engineering and machinery
Divisions: Faculty of Industrial Technology > Material & Metallurgical Engineering > (S1) Undergraduate Theses
Depositing User: - Taufiq Rahmanu
Date Deposited: 26 Nov 2018 02:41
Last Modified: 26 Nov 2018 02:41
URI: http://repository.its.ac.id/id/eprint/60002

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