HJ’s fuel and lube oil filter is classified into two categories, fully automatic backflush filter and manual self-cleaning filter. With the introduction of Boll’s automatic back-flushing filtration technique in 1986, and automatic backflush filters 6.33, 6.23/6.24, 6.50, 6.40/6.41, HJ began to intensely focus on the automatic research and development of the production of automatic backflush filters. And finally, the ZFL series fully automatic backflush filter was born and received serious demand and a stellar reputation from shipbuilding manufacturers all over.