Abstract: A method can include selecting a ratio of a first effective cross-sectional area of a first component of a gas lift valve to a second effective cross-sectional area of a second component of the gas lift valve; charging a chamber of the gas lift valve; and positioning the gas lift valve in a pocket to expose the gas lift valve to a tubing pressure and a casing pressure, where transitioning of the gas lift valve from a closed state to an open state depends at least in part on the selected ratio. Various other apparatuses, systems, methods, etc., are also disclosed.

Abstract: A gas lift valve is provided with increased longevity and reliability for preventing backflow. A wide cylindrical sliding member stabilizes axial movement of a valve element in the gas lift valve. A wide spring around the sliding member biases the valve element toward closure during back flow. The spring is physically supported and guided by the sliding member and protected from gas flow injection by the same sliding member. A one-piece poppet version of the valve element provides a consistent closing seal, and the sliding member protects the valve seat and poppet from full force of an injected gas. A dart version of the valve element includes a hexagonal race for movement of the sliding member, which prevents rotational wear of components and provides a straight flow path for the injection gas with no sharp transitions to wear and no sharp angles to erode.