Abstract: A device for butt welding pipes (99A-B) comprises: a guide element (17) which can surround and can be fixed to one of the ends of the pipes, and a carriage (1) movable along the said guide element and having powered means (25) for moving it along the guide element (17), a welding torch (90), means (29) for feeding it and means (26) for supporting the said welding torch (90) and moving it vertically and horizontally with respect to the said carriage, and means of movement (27) for imparting the oscillatory movement to the said torch and for regulating the amplitude of oscillation and the position of the torch during this oscillation; the regulating and monitoring means (108) are of the electronic type; and means (104) are provided for generating a signal relating to the angular movement of the welding torch (90) during the oscillation.

Abstract: A command and control device for a coupling-welding machine for metal pipes within which the coupling-welding machine is positioned, the machine being movable within the pipe and being operable to weld the metal pipes together. The command and control device including a control unit associated with the machine, a command unit external to the pipe and an energy source connected to an external power supply by a power line, the control unit being cooperatively interconnected with command unit by the same power line.

Abstract: A device for internally butt-welding pipes, of the type comprising a support and guide frame (2) for an annular welding member (3), rotatable coaxially to the pipes (1) to be welded and carrying a plurality of welding units (4) each comprising support means (13, 14; 40, 41; 40A, 41A; 45, 46) for a spool (8, 8A, 8B) on which welding wire (7) is wound, and means (26) for automatically feeding said wire. The support means (13, 14; 40 41; 40A; 41A; 45, 46) are removably connected to walls (10A, B) of a support frame (10) for the welding units (4) so as to enable said means to be replaced and spools of different type to be used.

Abstract: A device for internally butt-welding pipes (1), of the type comprising a support and guide frame (2) for an annular welding member rotatable coaxially to the pipes to be welded, and carrying a plurality of welding heads (4), the device comprising at least one sensor (15) connected to a unit for controlling the movement of said member and arranged to sense the presence of said heads at predetermined points. The sensor (15) comprises a first part (5) arranged to emit a signal and a second part (6) arranged to modify said signal, said two parts being provided respectively in seats (7) provided in said support and guide frame (2) and in said annular welding member (3) or vice versa, said two parts being arranged in such a manner as to remain permanently separated from each other.