CASK, METHOD FOR SEALING IT AND METAL GASKET

摘要

PROBLEM TO BE SOLVED: To maintain sealing performance even if a cask is stored for a long time. SOLUTION: A metal gasket 2 is used to seal a space between a main body 501 of a trunk and a secondary lid 508. The gasket 2 has a structure where an inner skin 4 and an outer skin 5 are placed outside a coil spring 3 made of a shape memory alloy. Though the plastic deformation of the coil spring 3 occurs when the cask is sealed, the coil spring 3 recovers to an original condition due to the decay heat inside the cask and the bearing pressure on the gasket 2 is heightened to maintain sealing performance over a long time.