When screwing the items entered on the first problem. The thread of the tube fitted only after processing with a file in the pump head. The individual tubes could be screwed together, only with much effort, since burrs were present on the threads. I wanted to use the pump for pumping of fuel oil tanks. After the first 20 liters was found that the pump on the crank is not completely sealed (ordinary mess). For water barrels, the pump is I think to use for the very reasonable price.