Abstract: A poppet valve is designed in a manner that results in relatively low failure rates and/or operates with relatively little or no degradation in performance. The poppet valve may include one or more features, each independently or in combination, contributing to such high service life and/or performance. The poppet valve includes a body, a poppet, and a spring. The poppet valve may also include an interface between the poppet and the spring to permit relative rotation between the spring and the poppet. The poppet valve may also include a limit stop to prevent over-stressing the spring. The body may include one or more tapered walls to reduce interference with the spring. The spring may also be tapered. The poppet may include one or more tapered elements.