| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas purging tool, which keeps an oxygen concentration low by filling an inert gas in the inner part of a container that is limited to the vicinity of a penetration bead welding part when conducting penetration bead welding of an end plate to the manhole body of a container to seal the container. SOLUTION: An inner space 4 and an container inner space 5 other than a gas purging region are partitioned by opening the umbrella part of the gas purging tool within the manhole body. Ventilation is conducted between the container inner space 5 other than a gas purging region, which space is not charged with the inert gas, and a container outer space 54 through an inner cylinder 11 even after the partitioning, since a vent hole 53 is formed at an umbrella tip cap 18 of the gas purging tool. Thereby, the inner space 4, which is a gas purging region to be charged with the inert gas, does not become a passage for ventilation caused by the pressure difference between both spaces, so that the outflow of the inert gas from the inner space 4 and the inflow of air into the inner space 4, which are caused in the case of ventilation of the inner space 4, are prevented. Thus, the increase in oxygen concentration in the inner space 4 after charging of the inert gas is prevented. COPYRIGHT: (C)2007,JPO&INPIT |
