Abstract: An orifice holding spring disk. The spring disk is utilized to retain orifice(s) against a smooth flat platen surface. The spring disk may further comprise an inlet flow conditioning nozzle, provided in (a) a flow collimating configuration to produce a coherent flow waterjet, or (b) in a de-collimating configuration to produce a divergent waterjet. The spring disk has an annular outer ring, one or more through-holes, and counterbores to form wells in the spring disk. The wells are slightly larger in diameter than the particular orifice to be mounted and slightly shallower (in the water flow direction) than the thickness of the orifice. A nozzle cap compresses the platen and spring disc against a high pressure inlet tube. The outer diameter of the spring disk is forced to flex to the cap surface while the center portion is restrained by the orifice that is resting on the platen.

Abstract: A spring disk with a concentric through bore and a concentric counter bore of specific depth used to hold an orifice against a lapped surface of a nozzle cap in a waterjet assembly. Dimensions are chosen to provide adequate restraint without the need to force the orifice onto the spring disk. When orifice, spring disk and the retaining cap are assembled and the cap is tightened on the inlet nozzle, the spring disk is forced to the cap surface and the orifice becomes securely held and centrally aligned within the assembly.