Case study: Seal-less caustic circulation pump failure

A Saudi Aramco gas plant contains two (2 × 100%) lean caustic circulation seal-less pumps. The pumps are responsible for delivering the lean regenerated caustic with naphtha from the disulfides separator to the naphtha wash settler. The pumps are considered an essential component of the caustic regeneration loop that ensures removing the total sulfur from the natural gas liquids (NGL) products. Pump design. The pumps are 178-hp seal-less magnetic drive pumps with a rated flow of 294 gal/min (gpm) and a total differential head of 638 ft. The process fluid is totally contained inside the pump containment shell and depended on to remove the generated heat through internal lubrication paths. Th