• pump
    Equipment- English

    Understanding Net Positive Suction Head

    Atmospheric Pressure Until the early 17th century air was largely misunderstood. Evangelista Torricelli, an Italian scientist, was one of the first to discover that air, like water, has weight. He once said, “We live submerged at the bottom of an ocean of the element air.” The weight of this “ocean” of air exerts a force on the Earth’s surface called atmospheric pressure. Torricelli went on to develop the mercury barometer which now allowed for quantifiable measurement of this pressure. A mercury barometer uses a complete vacuum at the top of a glass tube to draw mercury up the tube. The weight of the column of mercury is equal to the…

  • Centrifugal Pump
    Equipment- English

    Pump Selection

    Type of Pump   The selection of type and construction of a pump is very important to meet the process specification and proper application. Knowledge of the variety of pumps in the market should be review. It is mentioned before, that there are two general types of pump in today’s industry: positive displacement and centrifugal (dynamic) pumps. Positive Displacement Pumps Positive displacement (PD) pumps work by allowing a fluid to flow into some enclosed cavity from a low-pressure source, trapping the fluid, and then forcing it out into a high-pressure receiver by decreasing the volume of the cavity. Some examples of PD pumps are: fuel and oil pump in most automobiles, the pumps on most hydraulic…