An expansion joint includes: an outer tube including first and second ends and extending therebetween, the outer tube including first and second flanges, the first being located at the first end, the second being located at the second end and connectable to a downstream pipe; an inner tube including third and fourth ends and extending therebetween, the inner tube being located inside the outer and including third and middle flanges, the third flange being located at the third end and connectable to the upstream pipe, the middle flange being located at a middle portion between the third and fourth ends; and a closure including an outer peripheral portion connected to the first flange, an inner peripheral portion connected to the middle flange, and an elastic portion connecting the outer and inner peripheral portions. The first end is spaced from the third and located between the third and fourth ends.

A vacuum cleaner for use in cleaning very hot crematory ovens has a suction head mounted on side wheels, and connected to a central fitting which receives compressed air through a stiff metal air supply pipe. An expansion pipe extends upwardly from the central fitting and is tipped frontwardly. The compressed air passes through the central fitting which incorporates a vacuum eductor which draws air flow in from the vacuum head. The hot air discharges through a filter cap at the upper end of the expansion pipe which retains a filter assembly of multiple screens against the upper end of the expansion pipe. Dust and small particles pass through the filter assembly to be carried away by hot air up the crematory chimney. Larger particles are retained by the filter assembly, and may be discharged downwardly from the vacuum head into a receptacle when the input compressed air is discontinued.