Let-down valve

Claim 1

In a let-down valve having a body with walls defining a cavity, pressurized fluid inlet and outlet openings in the body walls in communication with the cavity, an orifice plug located within the cavity having walls interposed between the inlet and outlet openings, at least two orifices in said plug walls arranged to direct pressurized fluid from the inlet opening into two respective streams impinging upon each other prior to exiting via the outlet opening, the improvement comprising: said orifice plug being generally a hollow cylinder with one end closed and the other end received over the outlet opening, a plurality of even number sets of orifices formed in the orifice plug side wall and circumferentially arranged and equally spaced, a valve stem having parts located within the valve body cavity and other parts slidably extending through an opening in said body and terminating externally of said body; and means carried by the valve stem parts within the cavity including a hollow sleeve slidingly received on the orifice plug, said sleeve being affixed to parts of the valve stem lying in the cavity and having a pair of openings in the sleeve side wall on opposite sides thereof which can be adjustably positioned to selectively uncover a first pair of diametrically located orifices, and said sleeve being rotatable by the valve stem to expose selectively other pairs of orifices originally covered by said sleeve and to cover the first pair of orifices.