HOUSTON, Oct 31 (Reuters) - Motiva Enterprises' 640,500 barrel-per-day (bpd) Port Arthur, Texas refinery along with two others in the east Texas Gulf Coast city, were operating normally after recovering from malfunctions, said people familiar with plant operations.

The Motiva refinery, which is the nation's largest by capacity, and Valero Energy’s VLO.N 380,000 bpd Port Arthur refinery sustained multiple unit upsets on October 26 because they lost nitrogen gas supply from a plant in Louisiana, sources at the two plants said.

(Reporting by Erwin Seba; Editing by Muralikumar Anantharaman)

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