CORDOBA, ARGENTINA--August 18, 2008--Researched by Industrial Info Resources (Sugar Land, Texas)--On August 11, Valero Energy Corporation (NYSE:VLO) (San Antonio, Texas) shut down the 65,000-barrel-per-day (BBL/d) light gas-oil distillate hydrotreater (D2) at the company's San Nicolas refinery in Aruba because of a broken valve. The 42,000-BBL/d Visbreaker unit, which was shut down on July 22 because of a problem in its main tower as well as fissure issues, remains offline and under maintenance.