A blood type (also called a blood group) is a classification of blood based on the presence or absence of inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system. complete blood type would describe a full set of 30 substances on the surface of RBCs, and an individual's blood type is one of many possible combinations of blood-group antigens.
Thus, cavitation is the name given to a mechanism in which vapor bubbles (or cavities) in a fluid grow and collapse due to local pressure fluctuations. These fluctuations can produce a low pressure, in the form of vapor pressure of the fluid.
In some systems, air can enter the pump through its shaft seal. Check the condition of the pump shaft seal and if it is leaking, replace it. Cavitation occurs when the volume of fluid demanded by any part of a hydraulic circuit exceeds the volume of fluid being supplied. This causes the absolute pressure in that part of the circuit to fall below the vapor pressure of the hydraulic fluid. This results in the formation of vapor cavities within the fluid, which implode when compressed, causing a characteristic knocking noise.