A cap configured for engagement with a coupling can comprise an annular ring extending circumferentially around an outer portion of the cap, the cap defining an inner end and an outer end disposed opposite from the inner end, the annular ring defining a sealing surface between the inner end and the outer end, the annular ring defining a raised lip at the inner end, the raised lip extending radially outward from the sealing surface; and a web, the web enclosing the annular ring.

A piping element assembly includes a coupling body and at least one gasket, the coupling body defining an interior cavity, the interior cavity in contact with the at least one gasket, the piping element assembly adapted for sealably connecting two lengths of pipe by insertion of the pipe lengths within the interior cavity and sealed by the at least one gasket.

An electrical isolator comprising: a first fluid-carrying member and a second fluid-carrying member spaced apart from said first fluid-carrying member; a resistive, semi-conductive or non-conductive component located between said first and second fluid-carrying member, wherein said resistive, semi-conductive or non-conductive component is adapted to convey fluid flowing from said first fluid-carrying member to said second fluid-carrying member; wherein said first fluid-carrying member comprises a first annular projection extending radially outwardly, and said second fluid-carrying member comprises a second annular projection extending radially outwardly such that an annular cavity is formed between the first and second annular projections; wherein the electrical isolator further comprises: a layer of circumferentially wound fiber-reinforced polymer in the annular cavity; and a layer of helical wound fiber-reinforced polymer extending over the first annular projection, the annular cavity and the second annular projection.

A connector element comprising a body, a locking mechanism and a seal. The seal comprises a base arranged facing, backward to a proximal surface and facing, forward to a distal surface of the body, as well as a lip. The lip extends parallel to a longitudinal axis of the body and forward, protruding from the base and defining a free front edge. The seal presents a peripheral notch that is arranged, radially to the longitudinal axis, between the base and the lip, which opens to the front of the seal and a bottom of which is delimited on the rear by a joining portion of the seal connecting the base and the lip. The seal is configured to press backward against the proximal surface, in alignment with the free front edge of the lip, according to a direction parallel to the longitudinal axis.

A thick-wall compression pipe fitting, comprising: a thick-wall fitting body for connecting arranged between two thick-wall steel pipe bodies for connection, wherein a sealing ring, a positioning retainer and a teeth ring is disposed between said thick-wall fitting body and said thick-wall steel pipe bodies. Said thick-wall fitting body includes a middle connecting section, a first flared section and a second flared section extending to both sides to adopt a thick wall metal pipe. A special crimping tool is used to deform the fitting body for crimping to compress the socket section of the fitting body having a sealing ring and a high-strength teeth ring, so that the sealing ring in the socket section groove seals the steel pipe to stop leakage, wherein the high-strength teeth ring shrinks and firmly fastens the steel pipe so that the connection between the fitting body and the steel pipe can be completed instantly.

A pipe connecting apparatus includes: a connector including a large diameter part having a hollow, into which a pipe is inserted, therein and in which at least any one of opposite ends of the hollow has a larger inner diameter such that an accommodation space is formed inside the one end of the hollow, and a pressing part continuously formed along a lengthwise direction of the large diameter part in a direction in which the pipe is inserted, having a smaller diameter than the large diameter part, and formed to surround an outer peripheral surface of the pipe; a ring-shaped sealing member provided in the accommodation space and surrounding the pipe on the outside of the pipe; and a grip member provided in the accommodation space to be adjacent to the sealing member.

A flexible hose adapter configured for engagement with a coupling can comprise an end piece, the end piece defining an inner end and an outer end, the end piece defining an axis, the end piece defining a sealing surface and a raised lip, the raised lip defined between the inner end and the sealing surface; a flexible hose attached to the outer end of the end piece; and a socket end piece attached to the flexible hose opposite from the end piece.

Various embodiments include an adapter between two connectors and a coaxial coupling or a coaxial nipple. The two connectors are any combination of a separate coupling and a separate nipple. The adapter may include: a body with two cylindrical openings; a first element that fits in the first opening with connections for a first of the two connectors and the coaxial coupling or nipple; and a second element that fits in the second cylindrical opening, and a third connection for the other connector. The first element slides and rotates in the body and has a central axis eccentric to a central axis of the cylindrical first element part. The second element slides and rotates in the body. The central axis of the third connection is eccentric to a central axis of the cylindrical second element part.

A self-sealing fill nipple for a pressure regulator having a fill port, includes a body having a first end having a quick connect fitting, a mid-body region and a threaded region for threadedly engaging the pressure regulator at the fill port. The threaded region extends from about an end of the body toward the mid-body region and is spaced therefrom by a gap. The threaded region has crest and root diameters. The mid-body region includes a tightening element proximal the quick connect fitting and a gap between the tightening element and the threaded region. The gap has a diameter equal to or less than the threaded region root diameter. A combination of a pressure regulator and a self-sealing fill nipple are also disclosed.