An apparatus for generating high-speed pulsed fluid jets. A valve assembly has a valve body with an inlet and an outlet. A valve shuttle is slidably or movably mounted with respect to the valve body. The valve shuttle is positioned within a cavity of the valve body and divides the cavity into an upper or inlet cavity and a lower or outlet cavity. The valve shuttle has a passage in communication with the upper cavity and the lower cavity. In an open condition of the valve assembly, fluid communication is formed between the inlet, the inlet cavity, the passage, the outlet cavity and the outlet.