| 摘要 |
<p>A method and device for welding pipe (10) onto a piping network (12) at a joint (14) comprising introducing an inert purging gas under pressure at a substantially constant flow rate at one end of the pipe (10) away from the weld joint (14), providing a flow restriction at the end of the piping network (12) away from the weld joint (14), diverting a minor portion of the inert purging gas flowing through the piping network (12) into and through a constant back pressure maintaining device (38) for maintaining a substantially constant back pressure on the inert purging gas in the piping network (12) during the welding, whereby any changes in back pressure occurring in the piping network (12) cause a greater or lesser amount of the inert purging gas to flow through the constant back pressure maintaining device (38), thereby enabling producing of precise and highly reproducible welds with an orbital welder.</p> |
