Dongyou 640-class tanker

Dongyou 640 class oil tanker is a class of naval auxiliary ship currently in service with the People's Liberation Army Navy (PLAN). The name of this class is after the first unit commissioned, with the exact type still remains unknown, and a total of four of this class have been confirmed in active service as of mid-2010s.

Dongyou 640 class series ships in PLAN service are designated by a combination of two Chinese characters followed by three-digit number. The second Chinese character is You (油), meaning oil in Chinese, because these ships are classified as oil tankers. The first Chinese character denotes which fleet the ship is service with, with East (Dong, 东) for East Sea Fleet, North (Bei, 北) for North Sea Fleet, and South (Nan, 南) for South Sea Fleet. However, the pennant numbers may have changed due to the change of Chinese naval ships naming convention.