Studi Perbandingan Ekonomis dan Lifetime Pipa Underground NKL- 1061 Dengan Variasi Proteksi, pH Dan Suhu
The NKL-1061 Flowline is an oil and gas distribution pipeline from the well to the collection station. Wrapping protection on one of the underground pipes in the line is peeled off and corroded so protection replacement is recommended. The pipe material used is API 5L Gr. B 4 Inch Sch 40 in diameter. The pipe is open and in direct contact with the ground. Soil conditions with pH <7 or acidic cause corrosion on the pipe surface. If corrosion is not prevented, a decrease in pipe quality occurs. Corrosion can be overcome by changing underground protection. To find out better protection, corrosion rate, lifetime and cost calculation are calculated. Corrosion rate values were obtained from API 5L grade B material test results using the ASTM G31-72 standard immersion test method. The test is done by immersing the specimen in a solution of HNO3 (nitric acid) which has a varying pH and temperature also varies. The lifetime calculation is done based on API 570 and the minimum pipe thickness calculation based on ASME B31.4. . The highest average corrosion rate is in the state of the pipe with variations in painting with an average yield of 0.13817 mm / year. Then followed by a pipe in a cathodic protection state with an average corrosion rate of 0.11262 mm / year. While the lowest corrosion rate results are in the variation of painting + wrapping protection with an average yield of 0.09769 mm / year. The highest average lifetime value is in the state of the pipe with variations in painting + wrapping with an average yield of 47.1772 years. Then followed by a pipe in a cathodic protection state with an average lifetime of 40.8399 years. While the lowest average lifetime value is in the variation of painting protection with an average yield of 33,6448 years.