PURPOSE: To favorably execute the heat treatment in case of existence of a zone requiring cooling nearby the zone to be heat treated, by arranging the cylindrical heater, the flexible cooler, the sealing part for sealing the inert gas, etc., so as to satisfy specified mutual relation.
CONSTITUTION: When the heat treatment is applied from inside to the weld zone 3 between the tube 1 and the tube plate 2, being hardly approachable from outside and being nearby the zone 2A requiring the cooling, is employed the heat treating apparatus which is constituted into one body of the upper and lower sealing parts 10, 20, that are expandable by introducing the inert gas from the pipe 14 into the sealing rubber 12, the heater 50 including the electric resistance heating element 53 being buried in the outer surface of the heat insulating material 51, the upper and lower coolers 30, 40, including plural flexible cooling elements 31, 41, internally provided with the coolant path, etc.; in this heat treating apparatus, the upper cooler 30 is installed nearby the sealing part 10, and the lower cooler 40 nearby the heater 50; hereby, the heating of the zone 2A requiring the cooling and the sealing part 10, due to the welding heat, is prevented, and the weld zone 3 is favorably welded within the inert gas atmosphere.
KISHI SHIYUNICHI
WATANABE MASATOSHI
SHIFUJI EIZOU
OGUCHI ISAO
