FLOW-INFLUENCED CORROSION IN A WASTE ENERGY SPARGE LINE

An inclined section of a carbon steel sparge line (I-in. [2.5 cm] outs ide diameter) with intermittent flow (similar to 10-s cycles) from a l and-based steam boiler system had suffered failure after only 18 month s in service. The area of failure occurred near the line's outlet to a 4-in. (10-cm) condensate collection line. The sparge line had severe, jagged pitting along the upper half of the steamside surface near the 4-in. line. There were wall perforations near the sparge line/collect ion line joint, with pitting gradually decreasing over a 1-ft (30-cm) distance away from the joint. This article discusses the failure evalu ation and possible methods to contain the condition.