▁for ▁fuel ▁add it ives ▁is ▁either ▁mass ively ▁reduced ▁or ▁totally ▁removed . ▁A ▁typical ▁process ▁involves ▁a ▁single ▁pass ▁of ▁the ▁fuel ▁through ▁different ▁appar atus , ▁removing ▁increasing ly ▁fin er ▁cont amin ant ▁in ▁each ▁stage . ▁The ▁application ▁of ▁different ▁filter ▁techn ologies ▁is ▁vital ; ▁a ▁single ▁process ▁is ▁not ▁sufficient ▁to ▁extract ▁the ▁different ▁forms ▁of ▁water ▁and ▁matter ▁found ▁in ▁fuel . ▁ ▁During ▁the ▁fuel ▁pol ishing ▁process , ▁multiple ▁stages ▁are ▁required ▁to ▁effectively ▁remove ▁the ▁solid ▁particul ates , ▁wet ▁foreign ▁matter ▁and ▁water ▁from ▁the ▁fuel . ▁This ▁multi - stage ▁process ▁ens ures ▁the ▁high ▁efficiency ▁of ▁the ▁process ; ▁however , ▁ens uring ▁dense ▁matter ▁removal ▁first ▁is ▁key , ▁as ▁is ▁the ▁removal ▁of ▁large ▁matter ▁on ▁the ▁su ction ▁side ▁of ▁the ▁internal ▁p ump ing ▁stage . ▁High ▁press ur ization ▁of ▁fuel ▁cont am ination ▁is ▁not or iously ▁dangerous ▁and ▁as ▁such ▁the ▁majority ▁of ▁the ▁pol ishing ▁process ▁should ▁be ▁carried ▁out ▁on ▁the ▁su ction ▁side . ▁The ▁pressure ▁side ▁process ▁is ▁often ▁referred ▁to ▁as ▁the ▁final ▁or ▁finishing ▁stage , ▁where ▁ 2 ▁mic ron ▁partic ulate ▁is ▁removed ▁and ▁the ▁fuel ' s ▁final ▁water ▁content ▁is ▁extracted ▁to ▁within ▁the ▁efficiency ▁of ▁the ▁filter ▁stages . ▁▁ ▁The ▁amount ▁of ▁time ▁required ▁to ▁complete ▁the ▁fuel ▁pol ishing ▁process ▁depends ▁on ▁several ▁factors . ▁One ▁of ▁the ▁most ▁important ▁is ▁the ▁specific ▁fuel ▁pol ishing ▁machine ▁used .