Aspects of the disclosure relate to envelopes for aerial vehicle. The aerial vehicle may include an envelope including a plurality of gores. The aerial vehicle may also include a seal arranged between a pair of the plurality of gores, the seal including six layers of envelope material heat-sealed together.

An apparatus and method for joining pipes includes a plate for melting mating surfaces of the pipes to be joined. Additionally, the apparatus utilizes a vacuum in order to push the first and second pipes together in lieu of hand or mechanical pressure which may be inconsistent. Additionally, the vacuum allows the pipes to be joined to settle on each other in order to create a pressure about a periphery of the end of the pipe being joined to the other pipe. The consistent pressure creates a very strong joint between the first and second pipes.

A method and apparatus for assembling a high purity liquid distribution system is described. A distal end portion of the tube is heated then pushed over a sleeve so that the distal end portion can have a shrink seal fit over the sleeve to mitigate accidental or inadvertent pull out of the tube from a fitting. Other benefits are also achieved such as minimal flow restriction of the liquid flowing through the joint and the tube.

A heat sink for use in induction welding includes a number of tiles, wherein the tiles are electrically non-conductive and have a thermal diffusivity of greater than about 25 mm2/sec. A joint flexibly joins the tiles together.

A method of joining overlapping thermoplastic geomembrane components in which a first thermoplastic geomembrane component and a second thermoplastic geomembrane component are positioned in overlapping relationship between a pair of complementary molding surfaces, with one or more of the complementary molding surfaces being defined by an electrically conductive metal susceptor. Heat is generated in the metal susceptor and transferred by thermal conduction from the metal susceptor to overlapping portions of the first and second thermoplastic geomembrane components to locally melt and coalesce a portion or more of the thermoplastic material of the first thermoplastic geomembrane component and a portion or more of the thermoplastic material of the second thermoplastic geomembrane component. The molten thermoplastic material of the first and second thermoplastic geomembrane components forms a zone of coalesced thermoplastic material that, upon cooling, forms a solid weld joint.

An apparatus and method for joining pipes includes a plate for melting mating surfaces of the pipes to be joined. Additionally, the apparatus utilizes a vacuum in order to push the first and second pipes together in lieu of hand or mechanical pressure which may be inconsistent. Additionally, the vacuum allows the pipes to be joined to settle on each other in order to create a pressure about a periphery of the end of the pipe being joined to the other pipe. The consistent pressure creates a very strong joint between the first and second pipes.

A heat sink for use in induction welding includes a number of tiles, wherein the tiles are electrically non-conductive and have a thermal diffusivity of greater than about 25 mm2/sec. A joint flexibly joins the tiles together.

A method for fusing thermoplastic composite structures includes placing a substructure on an inner surface of a skin that is laid up on a shaping surface of a tool configured to maintain the shape of an outer mold line. The method further includes applying at least one insulation layer over a flange of the substructure and over exposed portions of the inner surface of the skin not in contact with the substructure, and applying a vacuum bag to at least partly enclose the skin and the substructure. The method yet still further includes applying heat to the shaping surface to fuse the substructure to the skin such that the skin exceeds its melting point and at least a portion of a raised segment of the substructure does not exceed its melting point.

A method of joining overlapping thermoplastic roofing membrane components in which a first thermoplastic roofing membrane component and a second roofing membrane component are positioned in overlapping relationship between a pair of complementary molding surfaces. Heat is generated in a metal substrate and transferred by thermal conduction from the metal substrate to overlapping portions of the first and second thermoplastic roofing membrane components to locally melt and coalesce a portion or more of the thermoplastic material of the first thermoplastic roofing membrane component and a portion or more of the thermoplastic material of the second thermoplastic roofing membrane component. The molten thermoplastic material of the first and second thermoplastic roofing membrane components forms a zone of coalesced thermoplastic material that, upon cooling, forms a solid weld joint.

A method of joining overlapping thermoplastic geomembrane components in which a first thermoplastic geomembrane component and a second thermoplastic geomembrane component are positioned in overlapping relationship between a pair of complementary molding surfaces, with one or more of the complementary molding surfaces being defined by an electrically conductive metal susceptor. Heat is generated in the metal susceptor and transferred by thermal conduction from the metal susceptor to overlapping portions of the first and second thermoplastic geomembrane components to locally melt and coalesce a portion or more of the thermoplastic material of the first thermoplastic geomembrane component and a portion or more of the thermoplastic material of the second thermoplastic geomembrane component. The molten thermoplastic material of the first and second thermoplastic geomembrane components forms a zone of coalesced thermoplastic material that, upon cooling, forms a solid weld joint.