A check valve, comprising: a liner, the liner defining a flow passage aligned along a longitudinal axis defined by the liner, the flow passage having an inlet portion and an outlet portion downstream from the inlet portion relative to the direction of the flow of fluid through the flow passage; a poppet, the poppet having a first flow face and a second flow face, wherein an axially extending sidewall of the poppet is interposed between the first and second flow faces (84, 86); and a biasing element operably coupled between the poppet and the liner to bias the first flow face against an annular seat defined by the liner in a closed position of the check valve; wherein the poppet is movable from the closed position to an open position wherein the poppet is unseated from the annular seat and from the open position to a full open position, wherein in the full open position an entirety of the axially extending sidewall is downstream relative to the direction of fluid flow through the flow passage from a downstream edge of the outlet portion; wherein a radial clearance is formed between the axially extending sidewall and the outlet portion of the flow passage such that a leakage flow is permitted from the inlet portion through the outlet portion in the open position; wherein the poppet comprises a stem leading to a head and wherein, prior to unseating, fluid pressure acts on a portion of the first flow face of the head of the poppet; and wherein the portion of the first flow face is defined radially between a radial inner face of the annular seat and a radial outer face of the stem; characterised in that the liner comprises a flange, wherein a plurality of extensions extend outwardly from the flange, and wherein outlet ports are situated between adjacent extensions. a liner, the liner defining a flow passage aligned along a longitudinal axis defined by the liner, the flow passage having an inlet portion and an outlet portion downstream from the inlet portion relative to the direction of the flow of fluid through the flow passage; a poppet, the poppet having a first flow face and a second flow face, wherein an axially extending sidewall of the poppet is interposed between the first and second flow faces (84, 86); and a biasing element operably coupled between the poppet and the liner to bias the first flow face against an annular seat defined by the liner in a closed position of the check valve; wherein the poppet is movable from the closed position to an open position wherein the poppet is unseated from the annular seat and from the open position to a full open position, wherein in the full open position an entirety of the axially extending sidewall is downstream relative to the direction of fluid flow through the flow passage from a downstream edge of the outlet portion; wherein a radial clearance is formed between the axially extending sidewall and the outlet portion of the flow passage such that a leakage flow is permitted from the inlet portion through the outlet portion in the open position; wherein the poppet comprises a stem leading to a head and wherein, prior to unseating, fluid pressure acts on a portion of the first flow face of the head of the poppet; and wherein the portion of the first flow face is defined radially between a radial inner face of the annular seat and a radial outer face of the stem; characterised in that the liner comprises a flange, wherein a plurality of extensions extend outwardly from the flange, and wherein outlet ports are situated between adjacent extensions.