A restrictor device for fluid circulation lizarse uti-forming means in a passage leading to high pressure fluid

摘要

A fluid flow restrictor for use in a high pressure valve or the like which comprises a series of closely interfitting concentric cylinders alternately attached to the valve seat and an axially movable valve plug of the valve. In one advantageous embodiment of the invention, various arrangements of slot openings are formed through the several cylinders. The slot openings may be of any geometric shape, for example, rectangular or trapezoidal, and are of sufficient volume to act as expansion chambers for a compressible fluid. The openings of each cylinder communicate with the openings of an adjacent cylinder by various overlapping relationships between openings or by viscous friction flow paths between the cylinders to form restricting flow paths therebetween. Axial displacement of the valve plug will move the interfitting cylinders with respect to one another to vary the flow path dimensions between the slot openings of the cylinders. In another specific form of the invention, the interfitting cylinders are slotless, providing a viscous friction flow path between cylinders and expansion chambers above the open ends of each cylinder and between adjacent cylinders.