Fire-resisting device for piping extending through a wall

A fire-resisting device for interconnecting two pipes of a piping extending through a wall, and in particular a horizontal flooring, comprising an annular case having a first portion which projects from the wall and a second portion which is embedded in said wall, a tubular element which is connected to the two pipes and defines a passage through the case and comprises a first section and a second section located respectively in the first portion and the second portion of the case, said tubular element being of a material which is rigid at ordinary temperature and capable of softening under the effect of heat, at least said first section being of a fusible material having a distinct fusion point, means combined with said first portion of the case for instantaneously closing said passage as soon as said first section has disappeared, and a material which is capable of radially swelling under the action of heat filling said second portion of said case.