Abstract: An electron beam welding chamber for butt joining elongate members 1,2 extending longitudinally at the center of the chamber. The chamber comprises an envelope 7 defining the welding enclosure 6 and which rests on a fixed structure 8. The electron gun equipment 13 is provided within the envelope and is mechanically connected, by a withdrawable connection means 18 or by elastic connection means 24, 25, to the enclosure, clamping means 15 being provided for clamping the electron gun equipment relative to one of the elongate members. This invention is particularly applicable to the welding of the sections of a pipe to be laid on the sea bed.

Abstract: A welding chamber in which a vacuum is created for welding, using an electron beam, elongate pieces extending centrally of the chamber. The welding chamber is divided into a central sub-enclosure 41 for receiving the pieces 1, 2 to be welded and which is evacuated during welding, and a peripheral sub-enclosure 42 in which the welding means are located and which is permanently evacuated, the two sub-enclosures being separated by retractable sealing gaskets 12, 26, 27 which are retracted during welding to place the two sub-enclosures in communication.