BACKING GAS SUPPLY DEVICE OF TIG WELDING

摘要

PURPOSE:To speedily and efficiently execute inert gas substitution at TIG welding of piping, etc. CONSTITUTION:The device is provided with a first supply means 21 to set the prescribed gas supply flow rate to the inside space 1b formed by tube bodies to be welded 1, 1a, a second supplying means 22 set to the backing gas supply flow rate lower than the former and an oxygen detecting means 23 to detect an oxygen concentration of the discharged gas from the inside space 1b. Further it is provided with a control means 24 to switch backing gas supply to the inside space 1b from the first supply means 21 to the second supply means 22 by the signal detected that an oxygen concentration from the oxygen detecting means 23 is lowered less than the prescribed value. The device speedily and efficiently executes precharge to the inside space, further surely executing substitution of inert gas and suppressing is consumption.