The propeller flow indicators are suitable for the passage of water, oil, gasoline, diesel and other liquids, excluding corrosive liquids. Important for the operation of the instruments is that the fluid is clean or better clear. These instruments do not perform any measurement function, they only serve to verify that there is fluid passage or not.
This extremely simple type of tools does not require special measures. Mounting of flow indicators can be installed in all directions. In order to be able to work the fluid inside the displays it must be clear to be able to see the movement of the propeller.