An elbow fluid flow valve exhibiting reduced flow loss and including a body having a specified shape and size and defining a short radius associated with an elbow shaped fluid passageway characterized by a first fluid flow inlet and a second fluid flow outlet. A cover secures over the valve body, and such that a generally sleeve shaped annulus is defined therebetween. A light-weight and linearly translatable sleeve is mounted exteriorly of the valve body and within the intermediately defined annulus. The sleeve is operable to be displaced between a first location permitting fluid flow to the outlet and a second location interrupting fluid flow. A control element is operably connected to a pair of access ports, in turn communicated with one or a pair of interior regions in communication with locations of the displaceable sleeve and, upon experiencing at least one of a pressure and flow disparity between valve inlet and outlet, facilitates displacement of the sleeve to the second (flow interrupting) location.