PURPOSE: To use a filter for hot dust-containing gas for long period of time by soldering flanges to a bellows telescoping section of heat- and corrosion resisting alloy through an intermediate ring of small heat capacity and giving solution treatment to the bellows telescoping section.

CONSTITUTION: A telescoping pipe fitting is composed of a bellows telescoping section 1 if heat- and corrosion-resistant alloyed steel such as austenitic stainless steel, etc., and flanges 3 of heat- and corrosion-resistant alloyed steel connected to both ends of the bellows telescoping section 1 through an intermediate ring 2 of small heat capacity of heat- and corrosion-resistant alloyed steel. Where the surface area of a member is A mm2, the volume of it is V mm3, and the ratio A/V mm1 is R, the R value of the bellows telescoping section 1 is more than 2 mm-1. Also, solution treatment is given to the whole bellows telescoping section 1. Thus, device for which a ceramic filter tube is used for removing dust from hot dust-containing gas can be operated stably for long period of time.