Specific Speed - Net Suction Specific Speed

Net Suction Specific Speed

The net suction specific speed is mainly used to see if there will be problems with cavitation during the pump's operation on the suction side. It is defined by centrifugal and axial pumps' inherent physical characteristics and operating point. The net suction specific speed of a pump will define the range of operation in which a pump will experience stable operation . The higher the net suction specific speed, then the smaller the range of stable operation. The envelope of stable operation is defined in terms of the best efficiency point of the pump.

The net suction specific speed is defined as:


N_{ss} = \frac{N\sqrt{Q}} {{NPSH}_R^{0.75}}

where:

net suction specific speed
rotational speed of pump in rpm
flow of pump in US gallons per minute
Net positive suction head (NPSH) required in feet at pump's best efficiency point

Read more about this topic:  Specific Speed

Famous quotes containing the words net, suction, specific and/or speed:

    Mental events such as perceivings, rememberings, decisions, and actions resist capture in the net of physical theory.
    Donald Davidson (b. 1917)

    It is the place where all the aspirations of the Western World meet to form one vast master aspiration, as powerful as the suction of a steam dredge. It is the icing on the pie called Christian civilization.
    —H.L. (Henry Lewis)

    Most parents aren’t even aware of how often they compare their children. . . . Comparisons carry the suggestion that specific conditions exist for parental love and acceptance. Thus, even when one child comes out on top in a comparison she is left feeling uneasy about the tenuousness of her position and the possibility of faring less well in the next comparison.
    Marianne E. Neifert (20th century)

    The greatest felony in the news business today is to be behind, or to miss a big story. So speed and quantity substitute for thoroughness and quality, for accuracy and context. The pressure to compete, the fear somebody else will make the splash first, creates a frenzied environment in which a blizzard of information is presented and serious questions may not be raised.
    Carl Bernstein (b. 1944)