An exemplary insulator for a flue of a residential oven includes a bendable insulating body having a first end, a second end, and a bending portion. A first cut is disposed between the bending portion and the first end and a second cut is disposed between the bending portion and the second end. The first cut is expandable to form a first opening and the second cut is expandable to form a second opening.

A piping connection unit of a combustion apparatus supplying and discharging air through a duct includes an apparatus-side connecting part, a connecting part and a spacer. The apparatus-side connecting part is to be connected to an air supply part or an exhaust part of the combustion apparatus. The connecting part has a diameter larger than a diameter of the apparatus-side connecting part, and communicates with the apparatus-side connecting part to be connected to a duct to be inserted from an opening part. The spacer is detachably disposed in the connecting part. The spacer is disposed between an inner wall of the connecting part and the duct to be inserted when the duct has a pipe diameter smaller than an inner diameter of the connecting part. The spacer is removed from the connecting part when the duct has a pipe diameter equivalent to the inner diameter of the connecting part.

An adapter and adapter system for coupling a female end of a first chimney portion to a male end of a second chimney portion. The adapter includes a first radial adapter portion, wherein a first inner surface and a first outer surface of the first radial adapter portion are coaxial. The adapter further includes a first locking interface protruding outward from the first outer surface and configured to engage with a first locking interface of the first chimney portion. The adapter further includes a second radial adapter portion with a second inner surface and a second outer surface extending along the first axis and a second locking interface protruding inward from the second inner surface and configured to engage with a second interlocking interface of the second chimney.

An exemplary insulator for a flue of a residential oven includes a bendable insulating body having a first end, a second end, and a bending portion. A first cut is disposed between the bending portion and the first end and a second cut is disposed between the bending portion and the second end. The first cut is expandable to form a first opening and the second cut is expandable to form a second opening.

An exemplary insulator for a flue of a residential oven includes a bendable insulating body having a first end, a second end, and a bending portion. A first cut is disposed between the bending portion and the first end and a second cut is disposed between the bending portion and the second end. The first cut is expandable to form a first opening and the second cut is expandable to form a second opening.

A method of relining a chimney includes: coating the inside surface of a chimney flue with a first layer of a flowable refractory material to provide a wet and sticky surface on the inside of the chimney flue; providing an insulating sleeve on the refractory surface so that the insulating sleeve adheres to the refractory surface; coating the inner surface of the sleeve with a second layer of flowable refractory material effective for hardening to provide a refractory surface on the inner surface of the sleeve; and allowing both layers of flowable refractory material to harden, thus providing a hardened relining comprising a first refractory layer, an insulating layer, and a second refractory layer on the inner surface of the sleeve.

A flexible hose liner is provided having a cylindrical body extending along a longitudinal axis from a first end to a second end. First and second sleeves form the cylindrical body by separate continuous ribbons having a plurality of convolutions formed in a helical pattern along the cylindrical body from the first end to the second end. A ring is formed in each revolution about the longitudinal axis of the continuous ribbon of the first and second sleeves. A plurality of rings form the cylindrical body, each ring has a first convolution and an ending convolution such that a mechanical connection is formed between the ending convolution of a preceding ring and the first convolution of a succeeding ring. The mechanical connection of the between the rings of the first sleeve being different from the mechanical connection of the rings of the second sleeve.

A piping connection unit of a combustion apparatus supplying and discharging air through a duct includes an apparatus-side connecting part, a connecting part and a spacer. The apparatus-side connecting part is to be connected to an air supply part or an exhaust part of the combustion apparatus. The connecting part has a diameter larger than a diameter of the apparatus-side connecting part, and communicates with the apparatus-side connecting part to be connected to a duct to be inserted from an opening part. The spacer is detachably disposed in the connecting part. The spacer is disposed between an inner wall of the connecting part and the duct to be inserted when the duct has a pipe diameter smaller than an inner diameter of the connecting part. The spacer is removed from the connecting part when the duct has a pipe diameter equivalent to the inner diameter of the connecting part.

A flexible hose liner is provided having a cylindrical body extending along a longitudinal axis from a first end to a second end. First and second sleeves form the cylindrical body by separate continuous ribbons having a plurality of convolutions formed in a helical pattern along the cylindrical body from the first end to the second end. A ring is formed in each revolution about the longitudinal axis of the continuous ribbon of the first and second sleeves. A plurality of rings form the cylindrical body, each ring has a first convolution and an ending convolution such that a mechanical connection is formed between the ending convolution of a preceding ring and the first convolution of a succeeding ring. The mechanical connection of the between the rings of the first sleeve being different from the mechanical connection of the rings of the second sleeve.

A flexible hose liner is provided having a cylindrical body extending along a longitudinal axis from as first end to a second end. First and second sleeves form the cylindrical body by separate continuous ribbons having a plurality of convolutions formed in a helical pattern along the cylindrical body from the first end to the second end. A ring is formed in each revolution about the longitudinal axis of the continuous ribbon of the first and second sleeves. A plurality of rings form the cylindrical body, each ring has a first convolution and an ending convolution such that a mechanical connection is formed between the ending convolution of a preceding ring and the first convolution of a succeeding ring. The mechanical connection of the between the rings of the first sleeve being different from the mechanical connection of the rings of the second sleeve.