Plant Air Units are crucial in the oil and gas industry, providing air for instrumentation. The process involves air compression, cooling, and drying. However, equipment like Wet Air Receivers can be prone to damage from corrosion and erosion, threatening operational reliability. Corrosion mechanisms, such as under-deposit corrosion, can occur due to high flow velocities and solid constituents in the stream. This case presents a study on corrosion erosion in air system piping, discovered during a malfunction of Wet Air Receivers level transmitters in a gas processing plant. Internal inspection revealed significant corrosion deposits, and technical evaluation identified corrosion erosion as the cause. The root cause was attributed to under-designed moisture traps in the air compressors, leading to excessive moisture breakthrough. The findings, operational and post-inspection results, repair strategies, and lessons learned are discussed. The importance of proper design and operational control to ensure efficient corrosion control and maintain the integrity of Plant Air Systems is highlighted. The study provides valuable insights for the oil and gas industry to prevent similar failures and optimize Plant Air Unit operations.
