Nitrogen saving device

A purge gas saving brazing installation, comprising:

• a dual torch gas shutoff valve for controlling the flow of fuel and oxygen through the brazing installation;
• dual inlet lines disposed on a first side of the gas shutoff valve for supplying fuel and oxygen to the shutoff valve;
• dual outlet lines disposed on a side of the gas shutoff valve opposite the inlet lines for delivering fuel from the shutoff valve;
• a brazing torch having-a first end with a torch tip disposed thereon and a second end having a pair of torch fittings disposed thereon, whereby the dual outlet lines are secured to the torch fittings to supply fuel and oxygen from the gas shutoff valve to the brazing torch, the oxygen and fuel each flowing through separate lines and then mixing inside of the brazing torch;
• a pivot arm having a hook end for supporting the brazing torch, the pivot arm being secured to the shutoff valve by a bracket that is pivotally mounted on the dual shutoff valve and movable to open and close the fuel and oxygen supplies to the brazing torch;
• a valve housing having a purge gas inlet passage, a purge gas outlet passage, and an intermediate gas passage orthogonal to and disposed between the inlet and outlet passages defined in the housing;
• a plunger having an upper end with a threaded opening and a lower end, the plunger being slidably disposed in the intermediate passage, said plunger adjustable between an open position and a closed position;
• an adjustment screw threadably engaged in the threaded opening of said plunger and extending from the upper end of the plunger;
• and
• a compression spring disposed beneath the plunger inside of the intermediate gas passage, the spring biasing the plunger to an open position in order to permit a purge gas to flow through the valve housing from the inlet passage to the outlet passage;
• wherein, the valve housing is adapted for attachment to a dual valve brazing installation for controlling flow of a fuel gas and oxygen with the adjustment screw disposed below the pivot arm of the brazing installation so that depressing the pivot arm depresses the plunger against the spring to block passage of the purge gas through the valve housing, whereby flow of the purge gas is controlled simultaneously with flow of the fuel gas and oxygen.