Abstract The reverse-jet pulse used to detach dust filter cakes is critical to the satisfactory operation of continuously-rated fabric dust filters. The design of these pulses can be optimised with regard to initial attack and peak overpressure under conditions which simulate practice. In all assemblies studied maximal values of the initial attack and peak pressure were obtained over a limited span of jet-injector separations. Such observations are in harmony with general principles of Jet Mixing theory where applied to pulsed injectors. Any restriction to the flow of secondary and induced air results in degraded pulses which exhibit increased intrinsic turbulence. Comparative values for commercial venturi assemblies are given and these are shown to be in accord with general design principles.