A. Hydrocarbon correction is the amount that NPSHR values required by a pump can be reduced when pumping hydrocarbons or high temperature water. See Figure 1.3.6.3.5b. The consistency of results that have been obtained on tests conducted with both water and hydrocarbon fluids suggests that NPSHR for a rotodynamic pump may be reduced when handling any liquid with a relatively high true vapor pressure at pumping temperature. However, since available data are limited to the liquids with temperature and vapor pressure relationships shown in Figure 1.3.6.3.5b, application of this chart to liquids other than hydrocarbons and water is not recommended except where it is understood that such usage can be accepted on an experimental basis. HI is the largest association of pump manufacturers in North America. Hydraulic Institute, Inc., 6 Campus Drive, First Floor, North, Parsippany, NJ 07054, 973-267-9700.