ESDU 80031 provides performance estimates for a wide range of rotodynamic pumps so that a suitable standard pump may be selected readily. This information which would otherwise only be available from a bulky collection of manufacturers' catalogues, is complemented by a methodical procedure to pinpoint the most suitable pump configuration. Charts giving rapid estimates of size and efficiency are given together with approximate correlations of suction and discharge flange sizes, and data showing the effects that liquids of high viscosity have on pump performance. The information is supported by a comprehensive example which, where the non-specialist user may require further guidance, is backed up by numerous cross references to ESDU 80030, which provides a general introduction to pump performance considerations.