[en] The motion of single solvent drops in water in pulsed sieve plate extraction equipment has been examined. It has been found that the nature of drop motion between plates is virtually the same as that for pulsed conditions in the absence of plates. Drops then suffer a time delay at plates which is a function of plate geometry, agitation conditions and the direction and velocity of pulsed water flow when a drop reaches a plate. An empirical correlation of characteristic drop velocity has been developed for use in slip velocity correlations of hold-up data for pulsed sieve plate liquid-liquid extraction equipment. Characteristic velocities obtained from experimental slip velocity data and the correlation are compared, and limits of applicability determined. (author)