A closure assembly includes a section of duct, a duct coupler assembly, a closure load plug, and an end cap. The duct coupler assembly is fit against the section of duct. The closure load plug is mechanically connected to the duct coupler assembly. The end cap is mechanically connected to the closure load plug.

A bell and spigot connection and composite gasket seat spigot ring provides seal mainline pipes (e.g. HDPE and SRPE pipes). An upper (HDPE) spigot sleeve defines an annular groove to provide a gasket seat and is welded to a lower (HDPE) sleeve. A metal ring is received in a ring cavity defined between the sleeves. The metal ring has a height that is a substantial proportion of its width, (e.g. 50% or more). A stepped spigot surface receives a liner surface at a pipe end for welding. A bell is formed on a first pipe segment from a second pipe segment having a same construction where the second segment is larger in diameter so that an exterior surface (e.g. a top of a helically wound rib or top of annularly spaced spacer blocks) of the first segment may be welded to an interior surface (pipe liner) of the second segment.

A retainer allows reduction in a length in a direction of insertion of a flexible pipe and capable of being engaged with the flexible pipe without requiring motions of other members. The retainer is a retainer having a shape of a ring and used in a pipe joint, including: a plurality of pawls for getting into a valley of a corrugated pipe of a flexible pipe to be inserted into the pipe joint; a plurality of supports for contacting an inner surface of a pipe joint body housing the retainer in the pipe joint, the supports being continuous with corresponding ones of the pawls as viewed in a direction of a center axis of the ring of the retainer; and a connector connecting the pawls and the supports in a plurality of combinations continuous with each other. The connector is more elastically deformable than the pawls and the supports.

A tubing apparatus includes corrugated tubing including convolutions of peaks and valleys in the body of the tubing; an electrically conductive or semi-conductive, polymer jacket disposed along an exterior length of the corrugated tubing; wherein the jacket provides protection to the inner corrugated tubing from damage resulting from electrical arcing at levels ranging from at least 9 coulombs at a waveform of 10 microseconds?1000 microseconds.

One aspect of the invention provides an elastomeric bushing including: a plurality of rigid members defining one or more internal annular ribs and one or more elastic members. The rigid members include: a first internal annular rib adapted and configured to engage a corrugation valley of corrugated tubing; and one or more trailing lips adapted and configured to extend through a central opening of a nut and engage said nut, thereby preventing axial movement of the bushing when a corrugated tubing is advancing through the bushing. The one or more elastic members are adapted and configured to: hold the plurality of rigid members in a substantially annular configuration; allow the plurality of rigid members to expand to allow a corrugation peak to pass under the first internal rib; and hold the plurality of rigid members against the corrugated tubing so that the first internal rib lies within a corrugation valley.

A connecting assembly (10) for connecting to a corrugated tube (12) includes a base body (14) with a receptacle recess (14a) for receiving the corrugated tube (12), and a latching unit (16) which can be introduced through a circumferential opening (14c) of the base body (14) into the receptacle recess (14a) and which has a latching element carrier (20) and a plurality of latching elements (22) constructed as one piece with the latching element carrier (20). The latching elements (22) are constructed for the purpose of engaging in a trough (12b) of the corrugated tube (12) and to resist a movement of the corrugated tube (12) out of the receptacle. The latching element carrier (20) is constructed as a split ring. The latching elements (22) are arranged uniformly distributed along the circumference of the latching element carrier (20).

A tubing apparatus includes corrugated tubing including convolutions of peaks and valleys; an electrically conductive or semi-conductive, polymer jacket disposed along an exterior length of the corrugated tubing; wherein the jacket includes a conductive material in an amount sufficient to protect the corrugated tubing from damage resulting from electrical arcing at levels of at least 9 coulombs at a waveform of 10 microseconds?1000 microseconds.

One aspect of the invention provides a bushing including: a plurality of rigid members defining one or more internal ribs including a first internal rib adapted and configured to engage a corrugation valley of corrugated tubing; and one or more elastic members adapted and configured to: hold the plurality of rigid members in substantially annular configuration; allow the plurality of rigid members to expand to allow a corrugation peak to pass under the first internal rib; and hold the plurality of rigid members against the corrugated tubing so that the first internal rib lies within a corrugation valley. Another aspect of the invention provides a fitting including: a body member defining a sleeve portion; and a bushing as described herein received within the sleeve portion of the body member.

The present invention relates to a connection structure of a metal corrugated pipe, which is used to connect metal corrugated pipes with each other or to connect a metal corrugated pipe to a boiler combustor. The connection structure includes a first connection member having one side, in which an external thread is formed on an outer surface of the one side and an inner surface of the one side has a diameter gradually reduced to form an inclined surface; a second connection member formed on an inner surface thereof with an internal thread screw-coupled with the external thread; and a heat-resistant packing fitted on the outer surface of the metal corrugated pipe, in which a front end of the heat-resistant packing is compressed by the inclined surface as the first connection member is screw-coupled with the second connection member.