A fluid flow control device comprising: a body having an inlet connection, an outlet connection, and a discharge port; and a booster module disposed within the body comprising a control element, an actuation element, a supply path extending between the inlet connection and the outlet connection and an exhaust path extending between the outlet connection and the discharge port, wherein the actuation element comprises a diaphragm assembly operatively coupled to the control element, the diaphragm assembly comprising an upper diaphragm, a lower diaphragm and a manifold; characterized in that, the manifold comprises a seating member, an upper sealing member, an upper support plate, a lower support plate and an outer cylinder portion, wherein the upper support plate, the outer cylinder portion and the lower support plate are disposed between the upper and lower diaphragms (122, 124), wherein the outer cylinder portion is affixed between the upper support plate and the lower support plate to provide a predetermined space between the upper and lower support plates (155, 156) and maintain a substantially parallel orientation between such plates (155, 156), wherein the height of the outer cylinder portion is a predetermined height to maintain separation between the upper and lower diaphragms (122, 124) during operation, wherein the central portion of the upper diaphragm is affixed between the upper sealing member and the upper support plate and the central portion of the lower diaphragm is affixed between the seating member and the lower support plate, wherein the seating member defines an axial opening, an internal cavity and plurality of internal radial passages, the axial opening defining an exhaust port providing fluid communication between an exhaust chamber of a lower portion of the body and the internal cavity, the plurality of internal radial passages providing fluid communication between the internal cavity and an annular passage disposed between the manifold and a spacer portion of the body; and wherein the outer cylinder portion comprises multiple passageways from an inner surface to an outer surface providing a plurality of exit paths for fluid flowing from the exhaust port to the discharge port, the multiple passageways arranged to distribute the fluid flow therethrough to substantially inhibit fluid flow jet interaction. a body having an inlet connection, an outlet connection, and a discharge port; and a booster module disposed within the body comprising a control element, an actuation element, a supply path extending between the inlet connection and the outlet connection and an exhaust path extending between the outlet connection and the discharge port, wherein the actuation element comprises a diaphragm assembly operatively coupled to the control element, the diaphragm assembly comprising an upper diaphragm, a lower diaphragm and a manifold; characterized in that, the manifold comprises a seating member, an upper sealing member, an upper support plate, a lower support plate and an outer cylinder portion, wherein the upper support plate, the outer cylinder portion and the lower support plate are disposed between the upper and lower diaphragms (122, 124), wherein the outer cylinder portion is affixed between the upper support plate and the lower support plate to provide a predetermined space between the upper and lower support plates (155, 156) and maintain a substantially parallel orientation between such plates (155, 156), wherein the height of the outer cylinder portion is a predetermined height to maintain separation between the upper and lower diaphragms (122, 124) during operation, wherein the central portion of the upper diaphragm is affixed between the upper sealing member and the upper support plate and the central portion of the lower diaphragm is affixed between the seating member and the lower support plate, wherein the seating member defines an axial opening, an internal cavity and plurality of internal radial passages, the axial opening defining an exhaust port providing fluid communication between an exhaust chamber of a lower portion of the body and the internal cavity, the plurality of internal radial passages providing fluid communication between the internal cavity and an annular passage disposed between the manifold and a spacer portion of the body; and wherein the outer cylinder portion comprises multiple passageways from an inner surface to an outer surface providing a plurality of exit paths for fluid flowing from the exhaust port to the discharge port, the multiple passageways arranged to distribute the fluid flow therethrough to substantially inhibit fluid flow jet interaction. wherein the seating member defines an axial opening, an internal cavity and plurality of internal radial passages, the axial opening defining an exhaust port providing fluid communication between an exhaust chamber of a lower portion of the body and the internal cavity, the plurality of internal radial passages providing fluid communication between the internal cavity and an annular passage disposed between the manifold and a spacer portion of the body; and wherein the outer cylinder portion comprises multiple passageways from an inner surface to an outer surface providing a plurality of exit paths for fluid flowing from the exhaust port to the discharge port, the multiple passageways arranged to distribute the fluid flow therethrough to substantially inhibit fluid flow jet interaction.