A slam-shut safety device, comprising: a valve body, the valve body having an inlet, an outlet, and defining a flow path extending between the inlet and the outlet, the valve body including a valve seat surrounding an orifice disposed between the inlet and the outlet; a valve disc, the valve disc disposed within the valve body and shiftable along a slam-shut axis between an open first position in which the valve disc is spaced away from the valve seat, and a closed second position in which the valve disc is seated against the valve seat; a reset pin operatively coupled to the valve disc and shiftable along the slam-shut axis relative to the valve body between an untripped position placing the valve disc in the open first position and a tripped position placing the valve disc in the closed second position, the reset pin arranged to respond to an actuator to shift the reset pin from the untripped position toward the tripped position; a plug support connected between the valve disc and the reset pin; a guide collar connected to the plug support and including a hollow cylindrical portion extending at least partly over the reset pin at a location adjacent to the valve disc, the guide collar slidably disposed in a guide bore of a slam shut body that is connected to the valve body and supporting the reset pin, the guide collar shiftable along the slam-shut axis between a retracted position, wherein a majority of the guide collar is disposed inside of the guide bore when the valve disc is in the open position, and an extended position, wherein the majority of the guide collar is disposed outside of the guide bore when the valve disc is in the closed position, the guide collar in contact with an inner wall of the guide bore for providing added structural integrity, characterized in that: a plurality of longitudinal guide ribs (180, 190) are disposed parallel to the slam-shut axis between the guide collar and the guide bore, the longitudinal guide ribs (180, 190) carried by one of the guide collar or the inner wall of the guide bore; and a plurality of longitudinal channels are disposed between the plurality of longitudinal guide ribs (180, 190), the longitudinal channels providing fluid communication between the flow path and an interior chamber of the guide collar to facilitate venting of the interior chamber when the guide collar shifts between the retracted and extended positions. a valve body, the valve body having an inlet, an outlet, and defining a flow path extending between the inlet and the outlet, the valve body including a valve seat surrounding an orifice disposed between the inlet and the outlet; a valve disc, the valve disc disposed within the valve body and shiftable along a slam-shut axis between an open first position in which the valve disc is spaced away from the valve seat, and a closed second position in which the valve disc is seated against the valve seat; a reset pin operatively coupled to the valve disc and shiftable along the slam-shut axis relative to the valve body between an untripped position placing the valve disc in the open first position and a tripped position placing the valve disc in the closed second position, the reset pin arranged to respond to an actuator to shift the reset pin from the untripped position toward the tripped position; a plug support connected between the valve disc and the reset pin; a guide collar connected to the plug support and including a hollow cylindrical portion extending at least partly over the reset pin at a location adjacent to the valve disc, the guide collar slidably disposed in a guide bore of a slam shut body that is connected to the valve body and supporting the reset pin, the guide collar shiftable along the slam-shut axis between a retracted position, wherein a majority of the guide collar is disposed inside of the guide bore when the valve disc is in the open position, and an extended position, wherein the majority of the guide collar is disposed outside of the guide bore when the valve disc is in the closed position, the guide collar in contact with an inner wall of the guide bore for providing added structural integrity, characterized in that: a plurality of longitudinal guide ribs (180, 190) are disposed parallel to the slam-shut axis between the guide collar and the guide bore, the longitudinal guide ribs (180, 190) carried by one of the guide collar or the inner wall of the guide bore; and a plurality of longitudinal channels are disposed between the plurality of longitudinal guide ribs (180, 190), the longitudinal channels providing fluid communication between the flow path and an interior chamber of the guide collar to facilitate venting of the interior chamber when the guide collar shifts between the retracted and extended positions. a plurality of longitudinal guide ribs (180, 190) are disposed parallel to the slam-shut axis between the guide collar and the guide bore, the longitudinal guide ribs (180, 190) carried by one of the guide collar or the inner wall of the guide bore; and a plurality of longitudinal channels are disposed between the plurality of longitudinal guide ribs (180, 190), the longitudinal channels providing fluid communication between the flow path and an interior chamber of the guide collar to facilitate venting of the interior chamber when the guide collar shifts between the retracted and extended positions.