Abstract: Multiple path means for a fluid flow control device is shown in connection with a typical spool type servo valve and a relief valve. The multiple path means consists of a stack of washer-like elements or disks which cooperate to define a number of finely divided flow paths across a stack of disks. To provide a configuration which is very economical of space, the disks are arranged such that the flow path turns back and forth through different planes. Groups of flow paths are defined by a number of groups of perforated disks confined between the imperforate disks. Two perforated disks having patterns of openings are positioned on opposite sides of a similar disk having a pattern of small orifices.

Abstract: Quieting means for a fluid flow control device is shown in connection with a typical pressure relief type valve. The quieting means consists of a stack of washer-like members or disks which cooperate to define a large number of finely-divided flow paths across the stack of disks. To provide a configuration which is very economical of space, the disks are arranged such that the flow path turns back and forth through different planes. Groups of flow paths are defined by a number of groups of two or three perforated disks confined between two imperforate disks. In one embodiment, two perforated disks having patterns of small vortical flow directors are positioned on opposite sides of a similar disk having a pattern of small orifices.