Method for reduced cycle times in multi-pass welding while providing an inert atmosphere to the welding zone

摘要

This disclosure describes a method and apparatus for controlling the temperature of a welding zone for welding together pipe sections. The temperature is controlled by a flow of inert gas through the pipes. The inert gas flow is cooled and acts as a heat sink to remove heat from the weld zone thereby controlling the weld zone temperature.

主权项

1. An apparatus for controlling interpass weld temperatures during a multi-pass welding operation, the apparatus comprising:
a) a support scaffold configured to position two or more pipe sections in an alignment suitable for welding the pipe sections together; b) a containment barrier configured to at least partially isolate an interior volume of the two or more pipe sections, wherein the interior volume includes a part of a weld zone; c) an inert gas delivery sub-apparatus comprising,
i) an inlet fluidly connected to the interior volume and fluidly connected to an inert gas delivery line,ii) the inert gas delivery line further fluidly connected to a source of inert gas,iii) an inert gas flow control device configured to control the flow of inert gas from the inert gas source into the interior volume, andiv) a vessel having an outer vessel and an inner vessel wherein the inner vessel is configured to hold a volume of cryogenic fluid; and d) a temperature control device comprising a cooling line at least partially disposed within the inner vessel, wherein the cooling lines is in fluid communication with the source of inert gas and the inert gas delivery lane, wherein the temperature control device is configured to adjust temperature of the flow of inert gas to a temperature between −226° C. and −156° C., when the cooling line is at least partially submerged in the volume of cryogenic fluid.