Abstract: An internal spacer and expander clamp for use when welding two sections of pipe together. There are two spider rings supported from a frame, one in one section of pipe and the other across the joint in the other pipe. Each spider ring has a plurality of holes with a piston with a pipe contacting pad in each hole. A rotor is supported within said spider ring. A linkage bar is pivotally connected at one end to the piston and at the other end to a pin in a cut-out in the rotor. The convex ends of the linkage bar mates with a concave cut-out in the piston and the other end in a concave cut-out in the rotor. A power linkage rotates the rotor such that in a first position the longitudinal axis of the piston is out of alignment with the longitudinal axis of the linkage bar and in a second rotational position thus are aligned forcing the shoe against the inner surface of the pipe with great force.

Abstract: A system for determining the bend in a section of pipe which is being bent by a bending machine which includes a stiffback and a pinup shoe. The pipe to be bent is placed in the stiffback and extends out the end at the pinup shoe and its angle S.sub.i is obtained of the pipe with respect to the horizontal. An outboard and an inboard cylinder force the pipe and the stiffback against a die to obtain a bend. This system is especially good for determining the angle of bend when the bending machine is on a non-level surface. After such bending, the angle of the pipe S.sub.h at the pinup shoe with respect to the horizon is made, and then subtracting S.sub.i from S.sub.n to obtain the angle of bend of the pipe. In another embodiment the angle detector is calibrated to read zero when the angle detector is measuring the actual angle the pipe makes with the horizontal before the pipe is bent.

Abstract: A new system for welding sections of pipe together to form a long, continuous pipeline. A welding bug is mounted on a guide track which goes around the circumference of the pipe. The welding bug is provided with a wire feeder, a motor to drive the wire feeder, and driving motor for driving the bug around the track. One may vary the speed of the bug and the wire feeder while the bug is continuously driven around the track. The welding head on the welding bug is powered by a surface-tension-transfer power source. The initial or root pass is made external of the pipe.

Abstract: A pipelayer machine including a tractor with rubber mounted tracks and a boom supported by the tractor for lifting and lowering the pipe to be laid. The boom is pivoted on one side of the tractor, and the boom line winch is supported on the other side. The boom line crosses in front of the windshield of the tractor and there are specially designed boom line cable fairleads at each front corner of the cab to prevent damage to the windshield and to the driver within the cab.