Fluid flowmeter valve

Claim 1

A combination needle flow control and shutoff valve for precision instruments comprising a body having a bore formed therein, fluid inlet and outlets ports communicating transversely with said bore, a sleeve slidably positioned within said bore for linear movement along the longitudinal axis of said bore, said sleeve being slidably movable in said bore between a first position in which the valve is open to allow fluid communication between said fluid inlet and outlet ports and a second position in which the valve is closed to prevent fluid communication between said fluid inlet and outlet ports, said sleeve having a metering chamber for regulating the flow of fluid through the valve, and a needle control valve threadedly engaged to said sleeve and extending into said metering chamber to precisely regulate fluid flow therethrough when the sleeve is in said first position; said sleeve having a plurality of O rings positioned therearound and spaced along its length for sealing the sleeve relative to the bore and forming a fluid inlet chamber between a first pair of said O rings and a fluid outlet chamber between a second pair of said O rings; said valve including at least one first radial bore in said sleeve connecting said fluid inlet chamber to said metering chamber and at least one second radial bore connecting said fluid outlet chamber to said metering chamber; said bore completely extending through said body, said sleeve extending completely through said bore and having an end flange arranged at each end thereof, the flanges adapted to be gripped so as to enable said sleeve to be axially moved within said bore, said flanges defining the extreme end positions of said sleeve relative to said bore.