During my internship at Basrah Gas Company, specifically at the NGL Khor Al-Zubair plant, I preformed a comprehensive study on the potential causes leading to over-pressurize the V-01 three-phase separator, focusing on the pressure relief valve. This project highlighted the critical importance of safety in the process industry and demonstrated the application of various safety methodologies.Key tasks and lessons learned included:• Analyzed scenarios that could lead to over-pressurization.• Evaluated the effectiveness of pressure relief valves.•Recognized the importance of implementing accurate process design principles as the first process safety layer.• Identified process safety layers to enhance operational safety.Additional lessons learned: • Natural gas processing. • Reading Piping and Instrumentation Diagrams (P&IDs).• Duties of Process engineers.