The relationship describing the shock wave velocity was formulated for the trickle-bed reactor operating at periodically changed feeding the bed with liquid phase. The values of shock wave velocity calculated from derived equations were compared with experimental values obtained for both fast and slow mode of base pulse periodic liquid feeding and using liquids differing in physicochemical properties. A good agreement between these two sets of values of shock wave velocity was obtained. It has to be emphasized that the relationship (Eq. (26)) derived in this study enables to estimate the values of the shock wave velocity when only mean values of variables of a process are known. (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.