to the turntable. The "jet spray" process is found to be adequate for cleaning applications that do not involve removal of difficult soils but in general the power wash process is the superior cleaning process. Power density A parts washer can be characterized by its power density. The power density is calculated by dividing the total horsepower of all the pump systems providing the wash function by the total work volume for that washing function. Typical units are horsepower per cubic foot. The results of this calculation offer a beginning point in comparing various parts washing systems. The power density number is also useful when it is desired to achieve the same cleaning standard and throughput in a different work volume. Note that the power density calculation does not take into account the pump system efficiency and assumes that all of the energy delivered to the pump is delivered to the wash load. A more accurate power density would consider the pump system efficiency as efficiencies vary greatly even from an identical pump as the efficiency is highly dependent on the pump operating point, the piping design and the friction losses in the system. References External links A Gasoline Sprayer for Cleaning Engine Parts, Popular Science monthly, February 1919, page 127, Scanned by Google Books: https://books.google.com/books?id=7igDAAAAMBAJ&pg=PT46 Metalworking tools Cleaning tools