Patent ID: 7921867

Claim:
A valve, comprising: a plug positioned within a valve body, the plug forming a main flow path comprising: an inlet, an outlet, and a smooth, arcuate bend, wherein the main flow path extends through the plug, wherein the flow path through the plug has a constant cross section orthogonal to the flow, and wherein the main flow path is oriented for a fluid to flow in a first direction at the inlet and in a second direction at the outlet; and a valve gate switchable between an open position and a closed position, wherein the gate in the open position is located substantially out of the main flow path, and wherein the gate in the closed position blocks the main flow path, wherein the gate comprises a linearly-translatable sleeve, wherein the arcuate bend comprises an arc of a substantially constant radius, wherein the first direction is substantially perpendicular to the second direction, wherein the plug is an integrally-formed cast metal plug, and wherein the sleeve is hydraulically controlled as a function of a pressure differential in the fluid at two positions in the main flow path, such that the sleeve translates from the open position to the closed position when the pressure differential exceeds a predetermined threshold.