{TAIL ~ A brazing oven} includes an arrangement employing a gas curtain or barrier to cover {HEAD ~ the port} or opening of the oven whenever the door is opened 
{ TAIL ~ A brazing oven } includes an arrangement employing a gas curtain or barrier to cover { HEAD ~ the port } or opening of the oven whenever the door is opened
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH