To seal leaked fluid which may not restrict the deformation of piping by a simple structure, by filling a liquid sealing compound between an inner cylinder concentrically formed in the piping projected from a casing and an outer cylinder concentrically formed on the outer side of this inner cylinder, and also storing an intermediate cylinder therebetween.

A sealing device 20 is equipped with an inner cylinder 23 which is concentrically formed in piping 21 and whose one end is fixed to a casing 22 and other end is formed at an opening free end, and an outer cylinder 24 which is concentrically formed on the outer side of the inner cylinder 23 and whose one end is fixed to the casing 22 and other end is formed at the opening free end. Also, the sealing device 20 is so formed that a liquid sealing compound 25 is filled between the inner cylinder 23 and the outer cylinder 24, and also an intermediate cylinder 27 equipped with a sealing plate 26 whose one end is formed at the opening free end and other end is fixed to piping 21, is stored therebetween. One end of the intermediate cylinder 27 is fixed to the piping 21 through the sealing plate 26, so that the intermediate cylinder 27 is made in a floated condition, therefore fluid can be sealed by retaining the piping 21 in a non-restricted condition against the deformation of the piping 21.