A flanged duct blank has a male part defined by lead notches formed at each side of a leading end and has a female part defined by trail notches formed at each side of a trailing end. The male part includes a lock tab. The female part includes a leg part and a Z-bend. The Z-bend includes a leg part and a gap. The duct blank is repeatedly clamped and bent by a pivoting wiper to form a duct portion. The pivoting wiper includes a clench tool that has a retractable rib and a retractable roller. With the lock tab inserted into the Z-bend and the retractable rib engaged with the Z-bend, the retractable roller clenches the leg part over the lock tab to lock the male and female parts together in a duct seam.

A flanged duct blank has a male part defined by lead notches formed at each side of a leading end and has a female part defined by trail notches formed at each side of a trailing end. The male part includes a lock tab. The female part includes a leg part and a Z-bend. The Z-bend includes a leg part and a gap. The duct blank is repeatedly clamped and bent by a pivoting wiper to form a duct portion. The pivoting wiper includes a clench tool that has a retractable rib and a retractable roller. With the lock tab inserted into the Z-bend and the retractable rib engaged with the Z-bend, the retractable roller clenches the leg part over the lock tab to lock the male and female parts together in a duct seam.

Methods and apparatuses for additively manufactured tubular passages, additively manufactured manifolds, and additively manufactured heaters are provided.

An insulated ductwork system particularly adapted for exterior use joins together pre-assembled air circulation duct sections that each have a ductwork passageway that is formed solely with insulation panels of foam insulation material disposed between foil sheets that are in turn covered by additional insulation material and an outer protective jacket to seal the ductwork from weather effects. The air circulation duct sections are used without traditional metal ductwork forming any part of the air circulation duct. Receiving flanges extend from the ends of each air circulation duct section and the duct sections are joined together in abutting relation with at least one slidably engageable sleeve that engages the flanges. A filler insulation is disposed over the sleeve. A closure band is disposed over the filler insulation and joined to exterior surfaces of the air circulation duct sections.

The present disclosure describes silicon carbide articles useful at high temperatures, and the method of making them. The method includes: providing a plurality of silicon carbide parts; providing a mullite gasket; placing the gasket between the ends of the parts to be joined to thereby form an assembly; applying a load in the range of 15-25 pounds per square inch to the parts' ends distal from the gasket to thereby press the gasket; heating the assembly in a muffle furnace under load to a temperature in the range of 1450 C. to 1550 C.; increasing the load on the to range of 30-50 pounds per square inch and holding the assembly at the temperature for a time in the range of 2-5 days to adhere the mullite gasket to the ends of the silicon carbide parts.

A fire-rated exhaust duct system comprising a modular configuration or structure. The fire-rated exhaust duct system comprises a plurality of exhaust duct sections. Each of the exhaust duct sections is configured to be joined or connected with other exhaust duct sections in the field or at an installation site, e.g. in building housing a kitchen facility or a laboratory facility to form longer sections or runs for exhaust duct system.

A fire-rated exhaust duct system comprising a modular configuration or structure. The fire-rated exhaust duct system comprises a plurality of exhaust duct sections. Each of the exhaust duct sections is configured to be joined or connected with other exhaust duct sections in the field or at an installation site, e.g. in building housing a kitchen facility or a laboratory facility to form longer sections or runs for exhaust duct system.

In order to improve sealing performance when the open end of a tank is swaged and thereby secured inside an annular groove the surface of which is formed in a substantially rectangular shape with a seal material between the groove an the tank, flange parts protrude in a fan shape at the four corners of the seal material, and those flange parts are pressed by the corner sections of the annular groove, thereby preventing the seal material from moving in the corner sections.

A fire-rated exhaust duct system comprising a modular configuration or structure. The fire-rated exhaust duct system comprises a plurality of exhaust duct sections. Each of the exhaust duct sections is configured to be joined or connected with other exhaust duct sections in the field or at an installation site, e.g. in building housing a kitchen facility or a laboratory facility to form longer sections or runs for exhaust duct system.

A fastening member for joining together adjacent duct sections includes a head and a shank extending from the head, the shank having an unthreaded space adjacent to the head and a threaded portion extending from the unthreaded space, the threaded portion threadedly engaging a hole of an inserted corner plate positioned in flange of a first duct section. When the fastening member is fully inserted, the inserted corner plate positioned in the flange of the first duct section is retained within the unthreaded space.