Failure Reason of Steam Jet Pump at Top of Vacuum Distillation Tower

The steam jet pump made of SAF 2205 duplex stainless steel at the top of the vacuum distillation tower in a petrochemical enterprise leaked. In order to clarify the cause of its failure, the chemical composition, corrosion morphology and corrosion products were analyzed, and some protective suggestions were proposed. The results show that severe selective corrosion was the primary reason for the failure of the steam jet pump. During the service of the jet pump, due to the action of flow and heat exchange, the water vapor condensed and dissolved acid gas, thus forming acid droplets, so the inner wall of the jet pump was in a typical HCl-H₂S-H₂O corrosion environment, and the wall surface was selectively corroded. At the same time, the erosion of the jet pump by high-speed fluid accelerated the thinning of the pump body.