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 oil tank, when the hydraulic pump is full of oil fluid, manually turn the coupling, till there is no bubble in the oil outlet.

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.