A fluid control valve comprising: a valve body having a first inner surface defining a chamber having a first axis and a second axis substantially perpendicular to the first axis, the chamber including an inlet and an outlet in communication with the chamber and substantially aligned along the first axis, the inner surface including an elongated seat member substantially aligned along the second axis, the seat member defining a groove, a portion of the body further defining a port in communication with the groove; a diaphragm member disposed within the chamber for controlling communication between the inlet and the outlet, the diaphragm member having an upper surface and a lower surface, the lower surface including at least a pair of spaced apart elongated members (114a,114b) defining a channel therebetween, the diaphragm member having a first position permitting communication between the inlet and the outlet and a second position wherein the elongated members (114a,114b) engage the seat member such that the channel is in communication with the groove to define an intermediate chamber in communication with the port; and an expansion member (150,160,170,180) disposed within the chamber for moving the diaphragm member into the second position, the expansion member (150,160, 170,180) having a base portion (152,162,172,182) and a plurality of radial projections (154,164, 174,184) extending from the base portion (152,162,172,182), each radial projection (154,164, 174,184) having opposing first and second ends (154a,154b), characterised in that the expansion member further comprises a flexure portion disposed between the first and second ends (154a,154b) to provide a converging orientation between the first and second ends (154a,154b), the flexure portion defining a converging center point about which the first and second ends (154a,154b) pivot when moving the diaphragm member into the second position. a valve body having a first inner surface defining a chamber having a first axis and a second axis substantially perpendicular to the first axis, the chamber including an inlet and an outlet in communication with the chamber and substantially aligned along the first axis, the inner surface including an elongated seat member substantially aligned along the second axis, the seat member defining a groove, a portion of the body further defining a port in communication with the groove; a diaphragm member disposed within the chamber for controlling communication between the inlet and the outlet, the diaphragm member having an upper surface and a lower surface, the lower surface including at least a pair of spaced apart elongated members (114a,114b) defining a channel therebetween, the diaphragm member having a first position permitting communication between the inlet and the outlet and a second position wherein the elongated members (114a,114b) engage the seat member such that the channel is in communication with the groove to define an intermediate chamber in communication with the port; and an expansion member (150,160,170,180) disposed within the chamber for moving the diaphragm member into the second position, the expansion member (150,160, 170,180) having a base portion (152,162,172,182) and a plurality of radial projections (154,164, 174,184) extending from the base portion (152,162,172,182), each radial projection (154,164, 174,184) having opposing first and second ends (154a,154b), characterised in that the expansion member further comprises a flexure portion disposed between the first and second ends (154a,154b) to provide a converging orientation between the first and second ends (154a,154b), the flexure portion defining a converging center point about which the first and second ends (154a,154b) pivot when moving the diaphragm member into the second position.