Lub twj tso kua mis roj phau ntawv yog ib qho khoom siv nqa tau uas siv lub zog siv phau ntawv los thauj cov roj oily, feem ntau rau cov ntawv thov uas tsis muaj hluav taws xob. Nws cov qauv tseem ceeb yog ua los ntawm siab -lub zog aluminium alloy, ua rau nws hnav, corrosion- tiv taus, thiab yooj yim nqa.
Cov cuab yeej no tuaj yeem tso cov roj uas tsis yog -corrosive xws li diesel, cav roj, thiab roj lubricating. Nws yog manually tsav los ntawm lub crank, txhawb ob qho tib si rau pem hauv ntej thiab thim rov qab kev sib hloov rau cov kua thiab nqus. Ua ntej siv, ib qho me me ntawm cov roj cav yuav tsum tau ntxiv rau lub twj tso kua mis rau lubrication. Nws yog txwv tsis pub siv los thauj cov roj av, kua qaub lossis alkaline kua, lossis lwm yam xov xwm tshwj xeeb.
