A gas-diffusing water-degradable welding purge dam apparatus for purging a weld zone of a pipe assembly having first and second pipes with respective first and second pipe ends to be welded together at a root gap. The purge dam apparatus includes a first air flow blocking member, a second air flow blocking member, and an interconnecting member interconnecting the first and second air flow blocking members. The interconnecting member has a hollow purge gas-receiving interior and a gas-diffusing sidewall that allows a pressurized purge gas in the gas-receiving interior to pass through the sidewall and exit therefrom in a diffused state into a weld zone external to the interconnecting member. An external purge gas entry port in the purge dam apparatus in fluid communication with the gas-receiving interior. The purge dam apparatus includes one or more water degradable materials so it can be flushed from the pipe assembly following welding.

A system and method of purge testing for welding piping, including flowing a purge gas through a test pipe, determining concentration of a gas component in the purge gas discharged from the test pipe, and determining a time period to reach a lower threshold of the concentration. The testing may consider different flow rates, pipe sizes, and inlet/outlet bore sizes.

Systems and methods are provided for a boss welding positioning tool. The boss welding positioning tool may, at least, include a purge base, a purge gas delivery connector, and features for aligning two items to be welded together. The purge gas delivery connector may be configured to be coupled to the purge base and may include ports that receive purge gas and deliver purge gas to an inner portion of the items to be welded.

A water-degradable welding purge dam apparatus for purging a weld zone of a pipe assembly having first and second pipes having respective first and second pipe ends to be welded together at a root gap. The purge dam apparatus includes a blocking plate assembly having an outer blocking plate, an inner blocking plate, and zero or more interior blocking plates. The blocking plate assembly may be formed from one or more water degradable materials to facilitate removal of the purge dam apparatus from the pipe assembly using an aqueous fluid following welding. At least one of the blocking plates may include a plurality of fluid flow apertures to aid distribution of the aqueous fluid through the blocking plate assembly. If desired, first and second ones of the blocking plate assembly may be ganged together by an interconnection assembly to form a ganged set of blocking plate assemblies.

There is described a method and associated apparatus for connecting a structure to equipment underwater, in particular for connecting a flange to a pipe under water. The pipe is provided under water, and a welding machine is provided in a welding space provided through a section of the pipe, and used to weld the flange to the end of the pipe, for example by internal metal inert gas welding.

A wireless oxygen monitor for monitoring oxygen in a weld zone. The oxygen monitor receives weld zone gas samples and an oxygen sensor detects oxygen levels. A controller generates gas sample oxygen level data and wirelessly transmits gas sample data via an oxygen monitor wireless communication interface to a remote device that displays the gas sample data and logs it in a remote device storage.

A welding power system including a controller with (a) a data input device via which a an operator can input parameters relating to a volume of an interior of one more pieces to be welded and (b) that calculates and outputs a purge time, the purge time being a time period needed to replace an atmosphere within the volume with a purge gas at a predetermined flow rate of the purge gas.

A welding system using a purge plug for data acquisition. In one example, a purge plug includes purge plug component having a sealing structure. The sealing structure is configured to abut a surface of a hollow device and to form a seal between the sealing structure and the hollow device. The purge plug also includes a sensor at least partly disposed in the purge plug component, the sealing structure, or some combination thereof. The purge plug component is configured to be disposed on a workpiece having the hollow device to purge an undesired gas from the workpiece

A welding power system including a controller with (a) a data input device via which a an operator can input parameters relating to a volume of an interior of one more pieces to be welded and (b) that calculates and outputs a purge time, the purge time being a time period needed to replace an atmosphere within the volume with a purge gas at a predetermined flow rate of the purge gas.

A purge dam assembly confines a volume within an assembly of pipes, including a distal pipe and a proximal pipe together arranged for butt welding at a seam. A distal disk is covered at its periphery with a distal sock including gasketing material. A proximal disk is covered at its periphery with a proximal sock including the gasketing material. Each disk is sized such that the sock contacts but does not completely seal against an inner surface of one of the tubes or pipes permitting a purging flow of gas from the volume and past each disk. A cross-member having a proximal and a distal end, the proximal end is affixed to the proximal disk and the distal end is affixed to the distal disk to preserve the spatial separation between the proximal disk and distal disks and to maintain the proximal and distal disks in coaxial alignment.