Automatic welding and cutting of Jet standard joint configuration

The automatic welding and cutting trolleys developed for the JET standard lip weld joint are driven electrically on roller bearings which clamp pneumatically the lip (2 x 2 mm) forming the standard JET edge weld configuration. Arc voltage control is used to follow irregularities on the lip edges and geometric changes when the welding trolley moves around corners. Pulse welding makes it possible to work in any attitude. On the cutting trolley the TIG torch is replaced by a nibbler which cuts the joints ready for rewelding, all material offcuts being captured by a vacuum system. It also allows flush trimming of two joint lips, thus allowing subsequent welding even with imprecise initial alignment. To date, 250 metres of lip joint have been trolley-welded, without detectable leak, and over 180 metres cut with the cutting trolley. Typical weld penetrations in the range of 1.7 to 2.5 mm have been achieved, depending on the lip material and the shielding gas