The Type 631 tanker is a type of naval auxiliary ship currently in service with the People's Liberation Army Navy (PLAN), and has received NATO reporting name Fuchang class. Originally designed as a type that is capable of transport both water and oil, but only the oil tanker version entered service with PLAN (as of early 2020s).

Type 631 tankers in PLAN service are designated by a combination of two Chinese characters followed by a three-digit number. The second Chinese character is You (油), meaning oil in Chinese, because these ships are classified as oilers. 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 are subject to change due to changes of Chinese naval ships naming convention, or when units are transferred to different fleets. Type 631 can be easily distinguished from other transport oilers by its transfer stations amid ship that enables it to carry out underway replenishment missions. Another visual cue of this class is that from the bow to the midsection of the ship, there are three levels of freeboard, while all other Chinese tanker has a smooth curvy transition. Specification: Displacement: 2,300 long tons (2,300 t) Length: Beam: Draft: Propulsion: 2 marine diesel engines @ 2 shafts Speed: Complement: 30 Type NATO designation Pennant No. Name(English) Name(Han 中文) Commissioned Displacement Fleet Status Type 631 transport oil tanker (AOT) Fuchang class Bei-You 565 North Oil 565北油 565 ? ? t North Sea Fleets <span style="color:green">Active</span style="color:green"> Dong-You 631 East Oil 631东油 631 ? ? t East Sea Fleet <span style="color:green">Active</span style="color:green"> Dong-You 641 East Oil 641东油 641 ? ? t East Sea Fleet <span style="color:green">Active</span style="color:green"> Nan-You 957 South Oil 957南油 957 ? ? t South Sea Fleet <span style="color:green">Active</span style="color:green"> Nan-You 959 South Oil 959南油 959 ? ? t South Sea Fleet <span style="color:green">Active</span style="color:green"> Nan-You 973 South Oil 973南油 973 ? ? t South Sea Fleet <span style="color:green">Active</span style="color:green">

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