Analisis Tegangan Sistem Perpipaan Pada Line Outlet Gas Injection Scrubber Menuju Gas Injection Compressor Dengan Penambahan Support

Abstract

This study re-evaluates the piping system of an 8-inch diameter line connecting the gas injection scrubber outlet to the gas injection compressor, designed for 220 °F and 2700 psi. The analysis was conducted as part of a project to convert a tanker into an FPSO. During construction, a 2.8 mm misalignment was detected at a flange-to-flange connection, leading to installation of supports. This modification required recalculation to verify compliance with design codes. The evaluation included maximum allowable pipe span, stresses from sustained, occasional, and thermal expansion loads, flange leakage, nozzle loads, and dynamic behavior using modal analysis. Results showed a maximum allowable pipe span of 13 meters. Stress from sustained loads decreased 14.95% to 4822 psi, while occasional loads dropped 15.85%. Thermal expansion stress increased by 203.6% to 558.14 psi due to restricted movement. Flange leakage remained below the permissible limit. Nozzle loads on the compressor satisfied criteria, but scrubber nozzle loads exceeded the limit. After adding LIM and Z+ supports, nozzle loads were reduced and met allowable values. Modal analysis indicated a first natural frequency of 12.664 Hz, confirming safety from resonance. Overall, the re-analyzed piping system with the added supports was found safe and compliant with ASME B31.3.