Finally there are mechanical skimmers - ideal for retrieving heavy oils - which use metal tooth discs, grab buckets and drum separators to remove the oil then pump it into a tank.
Fill oil into the oiltank, when the hydraulic pump is full of oil fluid, manually turn the coupling, till there is no bubble in the oil outlet.
向油箱灌油，当油液充满液压泵后，用手转动联轴节，直至泵的出油口出油并不见气泡时为止。
3
B, single screw pump before adding buffer tank in pipeline, the buffering can store a certain amount of crude oil, and a current limiting device for mixture pumps supply a certain amount of crude oil.