Patent ID: 6979422
Filing Date: 2005-12-27
Classification: F23D

Abstract:
1. A fitting for being mounted to a head of a torch for receiving at least fuel from the head and restricting flashback, the fitting comprising: a fuel passageway having a fuel inlet proximate a first end of the fitting for receiving fuel from the head, and a fuel outlet for discharging the fuel; and an annular valve plug movably positioned in the fuel passageway for moving from an open position to a closed position in response to reverse flow in the fuel passageway, so as to restrict flashback from passing through the fuel passageway, wherein the valve plug includes a pathway, a portion of the valve plug extends completely around the pathway, the pathway is open while the valve plug is in the open position, and the pathway is closed while the valve plug is in the closed position, so as to restrict flashback from passing through the pathway; a valve seat that is in opposing face-to-face relation with a wall of the valve plug, wherein the wall of the valve plug defines a first opening to the pathway and is engaged to the valve seat while the valve plug is in the closed position, so that the first opening to the pathway is closed by the valve seat while the valve plug is in the closed position, wherein the wall of the valve plug and the valve seat extend obliquely with respect to an elongate axis of the fitting, with the elongate axis extending in a direction from the first end of the fitting to a second end of the fitting, wherein the pathway includes a second opening that is open to an annular groove of the valve plug, the groove encircling the elongate axis of the fitting and having a first end that is open to the fuel outlet of the upstream fuel passageway and is closer to the first end of the fitting than to the second end of the fitting, and the pathway extending radially away from the groove; and a porous structure having a multiplicity of convolute passageways extending therethrough, wherein the porous structure is positioned in an annular space of the fuel passageway to restrict flashback from passing through the annular space, a second end of the valve plug, which is opposite from the first end of the valve plug, is adjacent the porous structure, and the porous structure is positioned to function as a stop against which the second end of the valve plug abuts while the valve plug is in the open position.