A tube assembly includes at least first and second tubes configured for coupling at respective ends. The first and second tubes each include a base material, and a weld interface at the respective end. The weld interface is proximate to an inner diameter and an outer diameter of the first and second tubes, and includes a weld interface segment extending therebetween. A work hardened weld assembly couples the base material of each of the first and second tubes. The work hardened weld assembly includes a weld fusion zone between the weld interfaces of the first and second tubes and the weld interface segments of the first and second tubes. The weld fusion zone is work hardened and at least the weld interface segments of the first and second tubes are work hardened between the work hardened weld fusion zone and the base material of the first and second tubes.

An electric resistance welded steel pipe for a torsion beam, in which a chemical composition of a base metal portion contains, in terms of % by mass, 0.05 to 0.30% of C, 0.03 to 1.20% of Si, 0.30 to 2.50% of Mn, 0.010 to 0.200% of Ti, 0.005 to 0.500% of Al, 0.010 to 0.040% of Nb, and 0.0005 to 0.0050 % of B, the balance containing Fe and impurities, wherein: V.sub.c90, defined by the following Formula (i), is from 2 to 150, a mass ratio Ti/N is 3.4 or more, a microstructure of a wall thickness central portion in an L cross section at a base metal 1800 position is a tempered martensite, an average aspect ratio of prior γ grains in the tempered martensite is 2.0 or less, and a tensile strength in the pipe axis direction is from 750 to 980 MPa:
log V.sub.c90=2.94−0.75βa  Formula (i)
βa=2.7C+0.4Si+Mn+0.45Ni+0.8Cr+2Mo  Formula (ii).

An apparatus for shrouding the coated field joint area of connected line pipe segments, the shroud having first and second housing halves which have end walls which cooperate to form registering openings matching the diameter of the pipe to be shrouded, the housing halves forming a chamber. The housing can be of a clamshell design, being hinged on one side and having hasps, latches or the like on the other side to keep the shroud positioned once it is placed around the coated field joint area of a pipeline. An environment monitor is disposed in the chamber to measure conditions such as relative humidity and temperature.

Rooftop photovoltaic solar systems and methods for installing interconnection wiring for photovoltaic solar systems. Cabling systems can include cable support stands secured underneath shingles. Cabling systems can include molded rubber raceways mounted using raceway clips secured underneath shingles.

A welded connection kit for joining first and second lined pipes together includes a coupling sleeve to connect the first and second pipes together. The coupling sleeve has a thermal break in it. The coupling sleeve includes a first coupling member that attaches to the first pipe and a second coupling member that attaches to the second pipe. The first and second coupling members attach to each other to connect the first and second pipes. A first liner lines the first pipe and includes a first flange. A second liner lines the second pipe and includes a second flange. The first and second coupling members compress the first and second flanges together to form a fluid seal.

A welded connection kit for joining first and second lined pipes together includes a coupling sleeve to connect the first and second pipes together. The coupling sleeve has a thermal break in it. The coupling sleeve includes a first coupling member that attaches to the first pipe and a second coupling member that attaches to the second pipe. The first and second coupling members attach to each other to connect the first and second pipes. A first liner lines the first pipe and includes a first flange. A second liner lines the second pipe and includes a second flange. The first and second coupling members compress the first and second flanges together to form a fluid seal.

A resin joint 20 includes an outer cylinder 21 molded by a resin material capable of transmitting laser light and an inner cylinder 22 disposed facing the inner peripheral surface of the outer cylinder 21. An annular protrusion 22b that protrudes in the radial direction and extends in the circumferential direction is formed on the inner peripheral surface of the outer cylinder 21 or the outer peripheral surface of the inner cylinder 22. The axial end of the resin tube 10 is inserted into an annular space 30 and is deformed in the radial direction following the annular protrusion 22b, and a region deformed in the radial direction has a surface that is in contact with the inner peripheral surface of the outer cylinder 21. The inner peripheral surface of the outer cylinder 21 and the outer peripheral surface of the resin tube 10 are laser-welded.

A resin joint 20 includes an outer cylinder 21 molded by a resin material capable of transmitting laser light and an inner cylinder 22 disposed facing the inner peripheral surface of the outer cylinder 21. An annular protrusion 22b that protrudes in the radial direction and extends in the circumferential direction is formed on the inner peripheral surface of the outer cylinder 21 or the outer peripheral surface of the inner cylinder 22. The axial end of the resin tube 10 is inserted into an annular space 30 and is deformed in the radial direction following the annular protrusion 22b, and a region deformed in the radial direction has a surface that is in contact with the inner peripheral surface of the outer cylinder 21. The inner peripheral surface of the outer cylinder 21 and the outer peripheral surface of the resin tube 10 are laser-welded.

A system for securing first and second metal workpieces to a central metal workpiece located therebetween. The system includes clamps to secure the first and second metal workpieces in coaxial alignment with the central metal workpiece, which is rotatable about its axis. Heating elements heat opposed ends of the first metal workpiece and the central metal workpiece, and opposed ends of the second metal workpiece and the central metal workpiece, to a hot working temperature. While the opposed ends are at the hot working temperature, the opposed end of the first metal workpiece is urged against the end opposed thereto of the rotating central metal workpiece, while the central metal workpiece rotates. At the same time, the rotating central metal workpiece's end opposed to the second metal workpiece is engaged with the opposed end of the second metal workpiece. The workpieces are allowed to cool, for bonding the opposed ends.

A system for securing first and second metal workpieces to a central metal workpiece located therebetween. The system includes clamps to secure the first and second metal workpieces in coaxial alignment with the central metal workpiece, which is rotatable about its axis. Heating elements heat opposed ends of the first metal workpiece and the central metal workpiece, and opposed ends of the second metal workpiece and the central metal workpiece, to a hot working temperature. While the opposed ends are at the hot working temperature, the opposed end of the first metal workpiece is urged against the end opposed thereto of the rotating central metal workpiece, while the central metal workpiece rotates. At the same time, the rotating central metal workpiece's end opposed to the second metal workpiece is engaged with the opposed end of the second metal workpiece. The workpieces are allowed to cool, for bonding the opposed ends.