Patent ID: 8136715

Claim:
A method of welding together a first pipe section and a second pipe section, said method comprising a) providing an internal pipe clamp apparatus comprising a frame; one or more clamping members, said one or more clamping members comprising one or more alignment guide devices, and said clamping members further comprising a means for supplying an inert purge gas directly to the area immediately surrounding a weld joint; a plurality of clamping members for engaging said adjacent ends of said first pipe section and second pipe section extensibly mounted to said frame, said plurality of clamping members being movable between a retracted position and an extended clamping position; 1) wherein each of said plurality of clamping members comprises a clamping shoe and a connecting member that connects said clamping shoe to said frame; 2) wherein each of said clamping shoes comprises a clamping surface which contacts the internal surface of said first pipe section and said second pipe section when said clamping members are in the extended clamping position; 3) wherein each of said clamping shoes comprises a longitudinal groove on said clamping surface, said longitudinal groove being oriented parallel to said adjacent ends of said first pipe section and said second pipe section, thereby dividing said clamping shoe into a first pipe contact surface and a second pipe contact surface; 4) wherein each of said clamping shoes further comprises at least one gas passageway through said clamping shoe, said gas passageway extending from a point on a surface of said clamping shoe away from said clamping surface to a termination point within said longitudinal groove on said clamping surface; and 5) wherein each of said clamping shoes further comprises one or more alignment guide devices protruding from one or more of said clamping surfaces along said longitudinal grooves; a means for delivering a purge gas to said groove through said gas passageway; and a means for moving said clamping members between said retracted position and said extended clamping position; b) inserting into said first pipe section and said second pipe section said internal pipe clamp apparatus; c) aligning the ends of said first pipe section and said second pipe section and creating the desired weld-joint gap between said ends of said first pipe section and said second pipe section using said alignment guide devices attached to said one or more clamping members of said internal pipe clamp apparatus; d) clamping in this position said first pipe section and said second pipe section using said one or more clamping members of said internal pipe clamp apparatus; e) supplying an inert purge gas directly to the area immediately surrounding the weld joint using said purge gas supply means of said one or more clamping members of said internal pipe clamp apparatus; and f) welding to one another said first pipe section and said second pipe section.