The disclosure relates to rapid informational prototypes of three-dimensional objects and systems having three or more dimensions, wherein the informational prototype includes information beyond outer physical shape, such as stress contours, thermal gradients, internal structures and elements, and elements varying with time. The rotatable valve spindle is according to the invention equipped with a projecting arm engaging a groove in a slide on the side of the body part. The handle arm includes an elongated hole. Preferably, the liquid-permeable panel has a plurality of holes that penetrate the liquid-permeable panel in the direction of thickness, and has as a material corrugated cardboard in which liquid goes through the aforementioned plurality of holes, passing through in the direction of thickness of the aforementioned liquid-permeable panel. The poppet is preferably adapted with a very low volume bypass port through which opposing pressures at valve inlet and outlet may be equalized for automatically resetting of the valve after the surge has passed, or a rupture has been repaired.