The invention relates to production of long spiral-welded large polymer products, as required for pipelines production, chemical, oil and gas and petrochemical industries, agricultural complex and utility services. The object of the invention is to create variants of spiral-welded polymer product with a cellular wall, having the internal or external, or internal and external uniform smooth walls with little material consumption, weight and cost. It should allow making products on site due the use of a thin-walled, lightweight, flexible profile. The object is solved owing to fact that a long hollow thermoplastic profile is used in spiral-welded polymer products, wherein the cross-section of the profile has a form of a closed geometric figure with a convex part having essentially the semi-ring shape and flat part that are connected each other, forming the convex and flat parts of the external surface of the profile, respectively.

A telescopic tube assembly includes a telescopic tube subassembly having a first tube and a second tube, a tubular member, a sleeve member, at least one retaining member, an actuating sleeve, and a biasing member for biasing the actuating sleeve to a locked position. When the actuating sleeve is in the locked position, the retaining member is engaged in a cavity of the tubular member to guard against axial movement of the second tube relative to the first tube. When the actuating sleeve is moved to an unlocked position against a biasing force of the basing member, the retaining member is disengaged from the cavity to permit the axial movement of the second tube.

A telescopic tube assembly includes a telescopic tube subassembly having a first tube and a second tube, a tubular member, a sleeve member, at least one retaining member, an actuating sleeve, and a biasing member for biasing the actuating sleeve to a locked position. When the actuating sleeve is in the locked position, the retaining member is engaged in a cavity of the tubular member to guard against axial movement of the second tube relative to the first tube. When the actuating sleeve is moved to an unlocked position against a biasing force of the basing member, the retaining member is disengaged from the cavity to permit the axial movement of the second tube.

A resin piping assembly including a base divisional component having first and second half components having respective first and second interfacial surfaces formed along an oil passage, and first and second divisional components which have respective third and fourth interfacial surfaces formed along the oil passage, and which are bonded to the respective first and second half components. Each of the base divisional component, and the first and second divisional components is formed of a resin material, and the first and second interfacial surfaces are spaced apart from each other, and open in respective opposite directions. The base divisional component further includes a cylindrical connecting pipe portion having a connecting passage portion which is a part of the oil passage and which is provided for communication between the first and second passage portions. Also disclosed is a process of forming the resin piping assembly.

A low-profile fluid collection conduit includes an elongate outer cover having an upper portion and a lower portion generally opposite the upper portion, with the outer cover being much wider than it is tall and defining an interior volume. An elongate rigid spacer is fitted within the interior volume of the elongate outer cover, with the elongate spacer allowing the majority of the interior volume to be unfilled so as to permit the flow of fluid along and within the elongate outer cover. The collection conduit is used with a fluid-impermeable membrane as part of a landfill fluid collection and conveyance system.

A low-profile fluid collection conduit includes an elongate outer cover having an upper portion and a lower portion generally opposite the upper portion, with the outer cover being much wider than it is tall and defining an interior volume. An elongate rigid spacer is fitted within the interior volume of the elongate outer cover, with the elongate spacer allowing the majority of the interior volume to be unfilled so as to permit the flow of fluid along and within the elongate outer cover. The collection conduit is used with a fluid-impermeable membrane as part of a landfill fluid collection and conveyance system.

A metal pipe including a curved portion produced by bending in which a plurality of non-bending surfaces and a plurality of bent portions at which the non-bending surfaces are connected in a bending manner are provided on a circumferential surface on an inside of a center of a curvature side of the curved portion is provided.

Embodiments of the present disclosure include a system for directing the flow of fluids via a production tree. The production tree extends upwardly from a lower surface to an upper surface and at least partially enclosing an upper section of a production bore and an upper section of an annulus bore, wherein one of a lower section and the upper section of the production bore includes a first production valve, the upper section of the production bore includes a second production valve, and the upper section of the annulus bore includes a second annulus valve.

Embodiments of the present disclosure include a system for directing the flow of fluids via a production tree. The production tree extends upwardly from a lower surface to an upper surface and at least partially enclosing an upper section of a production bore and an upper section of an annulus bore, wherein one of a lower section and the upper section of the production bore includes a first production valve, the upper section of the production bore includes a second production valve, and the upper section of the annulus bore includes a second annulus valve.

A fluid conduit has a longitudinal flow passage which includes a transverse cross section that is configured as a polygon, such as a convex or a concave polygon.