Description: height of the centre of the exhaust pressure gauge; Name: height of exhaust pressure gauge 
Description: Height of the zero or centre position of the outlet manometer, or other point as defined by the manometer calibration ; Name: Height of the outlet manometer
Description: amount of the absolute value of the total head above the head, equivalent to the vapour pressure of the liquid at the particular temperature, with reference to the NPSH datum plane; Name: net positive suction head