Systems, apparatus and methods for providing air and water to hot tub jets. The present teachings include jet assemblies, manifold assemblies, and related components, as well as methods of assembling hot tubs involving these components. In some cases, the present teachings describe the use of dual extrusion tubing to route air and water through adjacent, connected fluid conduits. In some cases, the present teachings describe a press-and-click method of connecting various components.

A double wall coaxial piping system with enhanced strength designed to transport a medium underground and minimize leaks is provided. The double wall coaxial piping system includes a plurality of pipe assemblies connected together to form a constructed pipe assembly with a first end and a second end. Each pipe assembly has an outer pipe and an inner pipe secured within the outer pipe. The inner pipe of each pipe assembly is continuously connected to the inner pipe of an adjacent pipe assembly in the plurality of pipe assemblies. Each end in the first and second ends of the constructed pipe assembly has a pair of plates coupled to the outer pipe of the pipe assembly at the end of the constructed pipe assembly and a packing layer disposed between the pair of plates.

One aspect of the invention provides a composite refrigeration line set including at least one selected from the group consisting of: a suction line and a return line, characterized in that one or more of the suction line and the return line are a composite refrigeration line set tube include: an inner plastic tube; a first adhesive layer positioned about the inner plastic tube; an aluminum layer positioned about the first adhesive layer and coupled to the inner plastic tube via the first adhesive layer; a second adhesive layer positioned about the aluminum layer; and an outer plastic layer positioned about the aluminum layer coupled to the aluminum layer via the second adhesive layer. The inner plastic tube is polyethylene of raised temperature. The outer plastic tube is polyethylene of raised temperature. The aluminum layer comprises AL 3005-O.

One aspect of the invention provides a composite refrigeration line set including at least one selected from the group consisting of: a suction line and a return line, characterized in that one or more of the suction line and the return line are a composite refrigeration line set tube include: an inner plastic tube; a first adhesive layer positioned about the inner plastic tube; an aluminum layer positioned about the first adhesive layer and coupled to the inner plastic tube via the first adhesive layer; a second adhesive layer positioned about the aluminum layer; and an outer plastic layer positioned about the aluminum layer coupled to the aluminum layer via the second adhesive layer. The inner plastic tube is polyethylene of raised temperature. The outer plastic tube is polyethylene of raised temperature. The aluminum layer comprises AL 3555-O.

One aspect of the invention provides a composite refrigeration line set including at least one selected from the group consisting of: a suction line and a return line, characterized in that one or more of the suction line and the return line are a composite refrigeration line set tube include: an inner plastic tube; a first adhesive layer positioned about the inner plastic tube; an aluminum layer positioned about the first adhesive layer and coupled to the inner plastic tube via the first adhesive layer; a second adhesive layer positioned about the aluminum layer; and an outer plastic layer positioned about the aluminum layer coupled to the aluminum layer via the second adhesive layer. The inner plastic tube is polyethylene of raised temperature. The outer plastic tube is polyethylene of raised temperature. The aluminum layer comprises AL 3004-O.

A pipe-in-pipe (PIP) pipeline assembly for the transport of a fluid in a marine environment that includes: (a) a PIP pipeline length comprising at least metal inner and outer pipes and an annular space thereinbetween, the inner metal pipe having an internal diameter; (b) a PIP bulkhead, having a first end connected to an end of the PIP pipeline length and comprising at least a metal inner pipe with a first internal diameter, an outer pipe, and an annular space thereinbetween, and a second end comprising an outer pipe with a second internal diameter, and being able to be joined to a second end of a second PIP bulkhead, wherein the second internal diameter of the second end is greater than the first internal diameter of the first end of the PIP bulkhead.

A duct bank assembly may include an elongate extending conduit with a length for receiving and passing through a cable or wire and an encasing body encasing the conduit along its longitudinal extent between a first mating end and an opposed second mating end of the body. Each mating end of the at least one elongate conduit has a male or female mating end for joining with a corresponding male or female mating end of an abutting duct bank assembly in a self-locking, self-sealing joint.

One aspect of the invention provides a composite tube including: an inner plastic tube; an aluminum layer circumferentially surrounding the inner plastic tube; and an outer plastic layer circumferentially surrounding the aluminum layer. The aluminum layer is an alloy selected from the group consisting of: AL 3004, AL 3005, AL 3105, AL 5052, AL 6061, and AL 8006. The aluminum layer has a thickness within a corresponding range disclosed for the alloy in Table 2. Another aspect of the invention provides: a composite tube including: an inner plastic tube; an aluminum layer circumferentially surrounding the inner plastic tube; and an outer plastic layer circumferentially surrounding the aluminum layer. The aluminum layer can be an alloy having 0.1% or greater magnesium by mass.

The subject matter described herein includes a tube for use in creating a support for a roof line of a structure. The tube comprises an inner flexible bladder, a seamless woven cylinder formed from fibers woven to form a seamless tubular arch shape when the cylinder is inflated, the cylinder engaged with the flexible bladder, and an outer weather shield coating engaged with the cylinder, wherein, in operation a plurality of tubes are used to form the roof line of a structure to define a housing for containing an article, wherein the plurality of tubes maintains flexibility so that the plurality of tubes can be inflated, deflated, and re-deployed.

A mounting arrangement for mounting one or more additional elongate members on a larger existing elongate member. The arrangement includes a base member mountable on the outside of the larger pipe and can be held thereon by a strap engaging with ratchet arrangements on the arrangement. A guide member with a generally n shaped configuration which may include an insert member, guides the smaller pipe or pipes.