| 摘要 |
PURPOSE:To capture the position and form of weld cracks by determining the presence thereof detecting the outflow of gas from between layers on the side of the outer layer after gas is forced between layers sequentially starting from the innermost side of a multi-layer wrapper pressure vessel. CONSTITUTION:A gas pressure feeder comprising a mandrel 11 having a feed hole 10 and an outer cylinder 12 is inserted into a detection hole T1 of a multi- layer-wrapped pressure vessel. Gas is forced through the feed hole 10 and then, it is checked whether the gas escapes outside through a clearance between a sealing O ring 19 and the outer cylinder 12 to acertain the airtightness of the O ring 19. A nozzle is inserted immediately before an innermost layer sheet 25 and gas is introduced from the direction of the arrow (a) to be fed between layers 13 in the direction of the arrow (b). If there is a weld crack in a sheet 26, the gas appears between layers 12, released from a clearance 30 between the detection hole T1 and the nozzle and detected. The nozzle is lifted by the thickness of the sheet gradually and the gas is detected from an outflow port 30 to capture the position and the form of the weld cracks. |
