[Jaringan pipa adalah salah satu sarana transportasi minyak dan gas yang palingaman dan ekonomis sehingga pipa tidak boleh mengalami kegagalan saatberoperasi. Pipa sambungan dalam suatu pipeline adalah pipa dengan geometriyang paling sering dijumpai. Jalur pipa transmisi biasanya ditanam didalam tanah(underground) sehingga rentan terhadap korosi eksternal. Oleh karena itu perludilakukan analisis keandalan, terutama pada geometri sambungan. Pengujiankeandalan dilakukan dengan menggunakan simulasi Monte Carlo. Untukmengetahui pengaruh tanah terhadap laju korosi pipa maka dilakukan pengukuranpH , resistivitas tanah dan laju korosi pipa pada setiap segmen. Hasil daripengukuran laju korosi pipa sambungan kemudian dibandingkan dengan lajukorosi pipa sambungan. Pengamatan mikrostruktur dilakukan untuk mengetahuipenyebab perbedaan laju korosi kedua jenis pipa tersebut. Nilai resistivitas tanahpada segmen I berada pada level very corrosive 􀀋􀀟􀀘􀀓􀀓􀈍-cm), segmen II beradapada level corrosive (500-􀀔􀀓􀀓􀀓􀀃 􀈍-cm), dan segmen II berada pada levelmoderately corrosive (1000-􀀕􀀓􀀓􀀓􀀃􀈍-cm). Nilai pH berada pada rentang 5-7 untuksemua segmen. Laju korosi pipa sambungan meningkat seiring penurunan nilairesistivitas tanah, dengan range nilai antara 0.03-0.75 mm / year. Keandalan pipasambungan pada segmen adalah 34,53%, segmen II adalah 64,04%, dan segmenIII adalah 99,78%, Pipeline is one mean of oil and gas transportation which is the most safe andeconomical so that the pipe should not fail during operation. Tee pipe in thepipeline is a pipe which geometry is the most frequently encountered.Transmission pipelines are usually planted in the ground (underground) so that itis susceptible to external corrosion. Therefore it is necessary to perform thereliability analysis, especially in a tee geometry. Reliability testing was doneusing Monte Carlo simulations. To determine the influence of soil on the rate ofcorrosion of pipes, the measurements of pH, soil resistivity and corrosion rate ofpipes on each segment were carried out. Results of tee pipe corrosion ratemeasurements were then compared with the corrosion rate of the straight pipe.Microstructural observations was performed to determine the cause of differencesin the corrosion rate of the two types of pipe. Soil resistivity values in the segmentI was at the very corrosive level 􀀋􀀟􀀘􀀓􀀓􀈍-cm), segment II at the corrosive level(500-􀀔􀀓􀀓􀀓􀀃 􀈍-cm), and segment II at the moderately corrosive level (1000-2000􀈍-cm). pH value was in the range 5-7 for all segments. Tee pipe corrosion rateincreases with the decreasing of soil resistivity values, ranging between 0.03-0.75mm / year. Reliability tee pipe segment was 34,53%, segment II was 64,04%, andsegment III was 99,78%]