“…The pressure of the water hammer responsible for erosion of the targets is composed of water hammer pressure and stagnation pressure, and it has been identified as a major factor driving rock breakage. 4,5 The pulsed water jet can be applied in several forms, such as compressed, interrupted and excited. 6 Of these, the interrupted pulsed water jet device controls the diameter, frequency and interval length of pulsed jet by adjusting jet pressure, rotational speed of the rotary disc, and the sizes of the nozzle, rotary disc and disc slots.…”