Fuel vessel stopped by RAF following one (8)
I believe the answer is:
paraffin
'fuel' is the definition.
(I know that paraffin is a type of fuel)
'vessel stopped by raf following one' is the wordplay.
'vessel' becomes 'pan' (vessel or container for cooking).
'stopped by' means one lot of letters goes inside another (I've seen this in other clues).
'following' becomes 'f.' (used when citing page numbers etc).
'one' becomes 'i' (Roman numeral).
'raf'+'f'+'i'='raffi'
'pan' placed around 'raffi' is 'PARAFFIN'.
(Other definitions for paraffin that I've seen before include "Liquid fuel" , "Flammable wax" , "Kerosine" , "Kerosene" , "Waxy flammable substance" .)