A needle valve having improved accuracy and wear characteristics is disclosed in which the valve stem is subjected to a constant force to prevent backlash throughout its entire movement with respect to the valve seat.Instrumentation Ball Valves In addition, the needle contained within the valve stem has a tapered end which moves within the cylindrical bore in a valve seat to control fluid passing through the valve and such needle is affixed to the valve stem only at its other end remote from its tapered end.Check Valves The needle thus floats for a substantial portion of its length and its tapered end is relatively flexible and free of movement. The needle is, however, angled with respect to its valve seat such that the needle physically makes contact with the internal surface of the valve seat and maintains that contact throughout its lateral movement within the valve seat.GATE VALVES A miniature needle valve having an improved internal body-to-bonnet metal-to-metal seal. The body seal incorporates a novel dovetail feature that improves the metal-to-metal contact forces as pressures increase. The space requirements of the seal are minimized in order to fit within a miniature valve body. The valve body can use dual outlet passageways to further minimize space requirements and improve the valve's flow characteristics. The body-to-bonnet seal improvements increase the pressure limits of the valve beyond similar-sized miniature needle valves of the prior art.

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