CURVE SHOWS APPROXIMATE PERFORMANCE FOR CLEAR WATER (International Test Standard ISO9906:1999 - Grade 2 unless otherwise specified).   For media other than water, corrections must be made for density, viscosity and/or other effects of solids.   WEIR MINERALS reserves the right to change pump performance and/or delete impellers without notice.   Frame suitability must be checked for each duty and drive arrangement.   Not all frame alternatives are necessarily available from each manufacturing centre.