Welding gas purging apparatus and method
OwnerJonathan E. Thodeinventor
Life of this patent
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Abstract
An apparatus and method for purging reactive gases from the vicinity of a molten weld during the welding process, having particular application to the welding of industrial process piping systems and pipelines, especially stainless steel and other alloy pipelines. A system is disclosed for boosting purging speed and efficiency by providing a multidirectional flow of purging gas adjacent to the interior walls of the pipe sections being joined. The rate of purge gas flow is automatically adjusted in response to changing gas pressures in the vicinity of the progressing weld.
Claims39
A welding gas purging apparatus comprising:
- at least two gas dams situated on opposite sides of a gap to be welded;
- and
- means for supplying a gas flow toward the gap from opposite sides of the gap.
A method of gas purging for welding, comprising the steps of:
- a) situating gas dams on opposite sides of a gap to be welded;
- and
- b) supplying gas flow toward the gap from opposite sides of the gap.
A method for purging gas from pipes during welding comprising the steps of:
- a) disposing two gas dams in pipes on opposite sides of a gap to be welded;
- b) sealably enclosing an interior space between the dams;
- c) introducing a bidirectional flow of gas into the interior space from opposite sides of the gap via at least two purge gas lines connected to a supply line;
- d) venting gas from the interior space via the gap;
- e) commencing to weld the gap;
- f) detecting the pressure within the interior space;
- and
- g) incrementally adjusting the discharge of gas into the interior space in response to pressure fluctuations detected in the interior space.
An apparatus for purging gas from pipes during welding, said apparatus comprising:
- at least two gas dams disposed in the pipes on opposite sides of a gap to be welded;
- means for sealably enclosing an interior space between said dams;
- at least two purge gas lines for introducing a bidirectional flow of gas into the interior space from opposite sides of the gap;
- means for venting gas from the interior space;
- a gas supply line connected to said purge gas lines;
- a pressure sensor connected to the interior space;
- and
- means for incrementally adjusting the discharge of gas into the interior space in response to pressure fluctuations detected in the interior space.
A gas dam apparatus for welding a section of pipe, comprising:
- a bulkhead plate;
- a retainer plate disposed parallel to said bulkhead plate;
- and
- an inflatable toroidal seal disposed between said bulkhead plate and said retainer plate;
- and
- means for directing gas flow parallel and adjacent to an interior wall of said section of pipe.
A gas purging apparatus for welding, comprising:
- two gas dams disposed within sections of a pipe, each said gas dam comprising
- a bulkhead plate;
- a seal, inflatable against one said pipe section and disposed adjacent to said bulkhead plate;
- and
- means for directing gas flow parallel and adjacent to the interior wall of one said pipe section;
- and
- at least one gas line connecting said two dam apparatuses.
Dependencies are inferred from the claim text.