A welding support block supports, from the rear surface of a joint to be welded, a weld pool created during a welding process. The welding support block comprises a block of metal and an outer layer of ceramic material providing a supporting surface. The ceramic material layer has a thickness between 0.25 mm and 1.5 mm. The metal material immediately beneath the ceramic material layer is made of steel. An internal line-up clamp for holding pipes in end-to-end alignment ready for welding may include multiple such welding support blocks. The use of such welding support blocks is particularly useful when laying a sour service carrying pipeline (high H.sub.2S content).

An orbital welding device (1) having a welding head (2), the welding head having a tubular mount (3) and a welding electrode holder (4) rotatably supported with respect to the tubular mount (3), the orbital welding device (1) having an electric motor (6) activated by a motor controller (5) of the orbital welding device (1), which is configured to drive the welding electrode holder (4) and thus to rotate the same with respect to the tubular mount (3), wherein the orbital welding device (1) has an electric torque measuring device (7), which is configured to measure a torque applied by the motor (6) to the welding electrode holder (4), wherein the torque measuring device (7) is connected to the motor controller (5), and wherein the motor controller (5) is configured to stop the motor (6) automatically if the torque exceeds a predetermined first torque.

An orbital welding device (1) having a welding head (2), the welding head having a tubular mount (3) and a welding electrode holder (4) rotatably supported with respect to the tubular mount (3), the orbital welding device (1) having an electric motor (6) activated by a motor controller (5) of the orbital welding device (1), which is configured to drive the welding electrode holder (4) and thus to rotate the same with respect to the tubular mount (3), wherein the orbital welding device (1) has an electric torque measuring device (7), which is configured to measure a torque applied by the motor (6) to the welding electrode holder (4), wherein the torque measuring device (7) is connected to the motor controller (5), and wherein the motor controller (5) is configured to stop the motor (6) automatically if the torque exceeds a predetermined first torque.

An orbital welding device (1) having a welding head (2), the welding head having a tubular mount (3) and a welding electrode holder (4) rotatably supported with respect to the tubular mount (3), the orbital welding device (1) having an electric motor (6) activated by a motor controller (5) of the orbital welding device (1), which is configured to drive the welding electrode holder (4) and thus to rotate the same with respect to the tubular mount (3), wherein the orbital welding device (1) has an electric torque measuring device (7), which is configured to measure a torque applied by the motor (6) to the welding electrode holder (4), wherein the torque measuring device (7) is connected to the motor controller (5), and wherein the motor controller (5) is configured to stop the motor (6) automatically if the torque exceeds a predetermined first torque.

An orbital welding device (1) having a welding head (2), the welding head having a tubular mount (3) and a welding electrode holder (4) rotatably supported with respect to the tubular mount (3), the orbital welding device (1) having an electric motor (6) activated by a motor controller (5) of the orbital welding device (1), which is configured to drive the welding electrode holder (4) and thus to rotate the same with respect to the tubular mount (3), wherein the orbital welding device (1) has an electric torque measuring device (7), which is configured to measure a torque applied by the motor (6) to the welding electrode holder (4), wherein the torque measuring device (7) is connected to the motor controller (5), and wherein the motor controller (5) is configured to stop the motor (6) automatically if the torque exceeds a predetermined first torque.

A welding jig (3, 103, 203) for holding a horizontal member relative to a vertical member is disclosed. The jig has a base (5, 105, 205) having a clamp (8, 108, 208) able to clamp the base to the vertical member and constituting a first, coarse, vertical adjustment mechanism. A frame (11, 111, 211) is interconnected to the base by a first threaded member (12, 112, 212) constituting a second, fine, vertical adjustment mechanism. A pair of supports (21, 121, 221) is slidingly mounted on the frame and movable between predetermined positions to constitute a first, coarse, horizontal adjustment mechanism. First and second vise parts (43, 44, 143, 144, 271, 272) each threadably mounted on a corresponding one of the supports and movable towards and away from each other constitute a vise mechanism for clamping the horizontal member.

A process of welding fittings to ends of a double wall pipe comprising forming a first welded joint between an inner pipe and an inner receiver of a first fitting; forming a second welded joint between an outer pipe and an outer receiver of the first fitting; forming a third welded joint between the outer pipe and an outer receiver of a second fitting; and forming a fourth welded joint between the inner pipe and an inner receiver of the second fitting.

A tank includes: a bowl-shaped head having a peripheral wall whose base end side is open; and a tubular body member having an end in an axial length direction joined to the head. The peripheral wall of a region of the head close to a base end is an inclined peripheral wall whose inner diameter increases toward the base end. The end of the body member is inserted inside the inclined peripheral wall of the head and is joined to an inner peripheral surface of the inclined peripheral wall via a weld. A mark available for use in determining a position of the end of the body member is provided in a position on an outer peripheral surface of the body member on a central part side of the body member in the axial length direction with respect to the head and away from the end by a predetermined dimension.

A tank includes: a bowl-shaped head having a peripheral wall whose base end side is open; and a tubular body member having an end in an axial length direction joined to the head. The peripheral wall of a region of the head close to a base end is an inclined peripheral wall whose inner diameter increases toward the base end. The end of the body member is inserted inside the inclined peripheral wall of the head and is joined to an inner peripheral surface of the inclined peripheral wall via a weld. A mark available for use in determining a position of the end of the body member is provided in a position on an outer peripheral surface of the body member on a central part side of the body member in the axial length direction with respect to the head and away from the end by a predetermined dimension.

A mobile pipe welding machine includes a welding unit for welding pipes and a pipe receiver for guiding a pipe to the welding unit. The pipe receiver has a distal end facing away from the welding unit and a proximal end facing towards the welding unit. On the distal end there is at least one linearly movable contact body for lifting the pipe.