(Adds Motiva no comment, background)
DALLAS, April 22 (Reuters) - Motiva Enterprises plans to shut a 200,000-barrel-per-day crude distillation unitand a reformer at its 600,000-bpd refinery in Port Arthur,Texas, in early May for two weeks of repairs, sources familiarwith refinery operations said on Tuesday.
The CDU, called VPS-4, and the catalytic reformer will beshut to clean out heat exchangers on the two units, the sourcessaid.
The work had originally been scheduled to begin in lateApril but was moved back to complete preparations, the sourcessaid.
A Motiva spokeswoman declined to discuss maintenance plansat the Port Arthur refinery
VPS-4 is the second-largest crude unit at the refinery,which is the nation's largest. The CDUs do the initial refiningof crude oil coming into the refinery and provide liquidfeedstocks for all other units.
The reformer, called CRU-4, converts refining by-productsinto blending components that boost the octane of gasoline.
Motiva is co-owned by Royal Dutch Shell Plc andSaudi Aramco (Reporting by Erwin Seba; Editing by Alden Bentley and Lisa VonAhn)