PREVENTING AMMONIUM SALT CORROSION IN HIGH PRESSURE FLASH GAS LINES

摘要

With increased requirement for deep desulfurization to meet market demand old refineries are facing higher risk of corrosion by ammonium salts. The paper describes failure of an ERW pipe in a high pressure flash gas line through which gases from Hydrocracker and Hydrotreatmg unite are sent to a centralized amme unit. To prevent similar failures a two prong approach has been made. First to minimize ammonium salt corrosion, specific limits of critical parameters have been developed which are monitored on a regular basis and corrective actions taken as required maintainng the parameters. Secondly, a risk analysis for all ERW piping in the refinery has been carried out and depending on risk rating of a piping, a replacement/inspection strategy has been developed.