Abstract: A portable hand-held oxygen monitor for monitoring oxygen in a weld zone includes a user interface having an alphanumeric display and one or more user interface buttons. An audiovisual alarm includes an indicator light and an audio output device, the indicator light being separate and distinct from the alphanumeric display. The oxygen monitor implements an oxygen monitoring mode responsive to activation of one or more of the user interface buttons, wherein (1) a gas sample is obtained, (2) a digital gas sample oxygen level value is generated, and (3) the gas sample oxygen level value is compared to a stored oxygen level alarm value, and the audiovisual alarm is activated if the gas sample oxygen level value is less than the oxygen level alarm value. The activating includes illuminating the indicator light and generating sound from the audio output device to alert a monitor user that is safe to weld.

Abstract: An inflatable purge dam apparatus includes first and second inflatable purge bladders defining a weld-zone therebetween. A purge gas discharge port is adapted to deliver a purge gas into the weld zone. A purge gas diffuser is in fluid communication with the gas discharge port. The purge gas diffuser is operable to diffuse the purge gas as it enters the weld zone.

Abstract: A field-customizable inflatable purge dam apparatus for welding includes first and/or second inflatable purge bladders. A bridge conduit extends between the purge bladders. First and second quick-disconnect couplers are provided for detachably connecting the bridge conduit to the first and second purge bladders, respectively. The quick-disconnect couplers allow the bridge conduit to be selectively attached to, and detached from, one or both of the first and second purge bladders. The purge dam apparatus can be field-customized by combining the bridge conduit with one or more different purge bladders. Alternatively, the purge bladders may be selectively combined with one or more different bridge conduits. In another aspect, one end of the bridge conduit may be detachably connected to a single inflatable purge bladder, and the other end of the bridge conduit may be adapted to connect to a purge gas source. Various purge dam apparatus sub-assemblies may also be provided.

Abstract: A purge dam for retaining a purge gas around a weld zone includes a purge dam structure configured to substantially obstruct an air passage leading to the weld zone. The purge dam includes a main blocking portion configured to substantially block the air passage. The purge dam structure further includes a wall portion configured to engage the air passage for attachment. Adhesive can be optionally provided on the wall portion to facilitate the air passage attachment. Some or all of the purge dam structure may be formed as a multi-layer structure that includes one or more layers of water degradable paper and one or more layers of water degradable polymer. If present, the optional adhesive may be applied to the water degradable polymer layer. The purge dam may be installed by placing the purge dam in the air passage and adhering the wall portion thereto.

Abstract: A water-degradable purge dam apparatus for purging a weld zone of a pipe assembly comprising first and second pipes having respective first and second ends. A first purge dam subassembly adapted for installation in the first pipe end has a hollow first conduit defining a first air flow pathway. A second purge dam subassembly adapted for installation in the second pipe end has a hollow second conduit defining a second air flow pathway. Each subassembly has one or more air flow blocking plates. A hollow third conduit, defining a third air flow pathway, is interconnectable to the first and second conduits members to span the weld zone. The first, second and third air flow pathways allow pressurized air within the pipes to pass through the purge dam apparatus and the weld zone in a sequestered by-pass zone defined by the first, second and third conduits.

Abstract: An inflatable purge dam apparatus for use with pipes of different nominal pipe size (NPS) includes first and second inflatable purge bladders, and an intermediate bridge conduit. In a first aspect, the purge bladders each comprise an expandable inner purge gas retaining liner and a heat-resistant stretchable outer protective cover. The protective covers comprise a heat-resistant stretchable material that is constructed to undergo variable stretching to increase the size of the purge bladders as they are inflated with purge gas to a desired sealing pressure, thereby allowing the purge bladders to form an effective weld zone seal in pipes of different NPS. In a second aspect, an air vent conduit extends between first and second ports located proximate to a longitudinal centerline of the first purge bladder. The air vent conduit provides a vent pathway for venting air from the weld zone through the first purge bladder.

Abstract: A water-degradable welding purge dam for purging a weld zone of a pipe assembly comprising first and second pipes having respective first and second ends to be welded together at a root gap. The purge dam includes a blocking plate comprising one or more plate members. The one or more plate members include a friction plate member having a plurality of flexible members on its periphery adapted to flexibly engage an inside wall of one of the first or second pipe ends in a self-retaining manner. The purge dam comprises one or more water degradable materials so that it can be flushed from the pipe assembly following welding.

Abstract: A welding spacer includes a spacer body having a first pipe-engaging face and a second socket-engaging face. The spacer may be formed from any suitable material, including a liquid-degradable or heat-degradable composition. A spacer thickness separates the first face and the second face. The spacer thickness may comprise solid material or it may have one or more hollow portions. A peripheral edge is provided on the spacer body. One or more deformable members may be provided on the peripheral edge for retaining the spacer in a structure. The welding spacer may be incorporated in a pipe assembly that includes a first pipe segment and a second pipe segment. The first pipe segment has a socket at a first pipe end with an interior shoulder to seat the welding spacer. The second pipe segment has a second pipe end that is received in the socket and seated against the welding spacer.

Abstract: A welding alignment and spacing article is provided for forming a welding gap between two structures to be welded together. The article includes a body having first and second surfaces that are spaced from each other at a selected spacing distance to define a region of selected body thickness. The body is formed from a non-metallic degradable body material in the region that can be wholly or partially degraded by exposure to a degrading agent to reduce the body thickness. The body is also formed from a non-degradable body material in the region. The degradable body material and the non-degradable body material are sufficiently incompressible to be useable as a spacer that maintains a specified welding gap distance between the two structures to be welded.

Abstract: A welding alignment and spacing article is provided for forming a welding gap between two structures to be welded together. The article includes a body having first and second surfaces that are spaced from each other at a selected spacing distance to define a region of selected body thickness. The body is formed from a non-metallic degradable body material in the region that can be wholly or partially degraded by exposure to a degrading agent to reduce the body thickness. The degradable body material is sufficiently incompressible to be useable as a spacer that maintains a specified welding gap distance between the two structures to be welded.

Abstract: A welding alignment and spacing article is provided for forming a welding gap between two structures to be welded together. The article includes a body having first and second surfaces that are spaced from each other at a selected spacing distance to define a region of selected body thickness. The body is formed from a non-metallic degradable body material in the region that can be wholly or partially degraded by exposure to a degrading agent to reduce the body thickness. The body is also formed from a non-degradable body material in the region. The degradable body material and the non-degradable body material are sufficiently incompressible to be useable as a spacer that maintains a specified welding gap distance between the two structures to be welded.

Abstract: A welding alignment and spacing article is provided for forming a welding gap between two structures to be welded together. The article includes a body having first and second surfaces that are spaced from each other at a selected spacing distance to define a region of selected body thickness. The body is formed from a non-metallic degradable body material in the region that can be wholly or partially degraded by exposure to a degrading agent to reduce the body thickness. The degradable body material is sufficiently incompressible to be useable as a spacer that maintains a specified welding gap distance between the two structures to be welded.

Abstract: A degradable paper article with long-shelf-life adhesive backing, together with a related fabrication method. The article includes a layer of degradable paper, a layer of degradable pressure sensitive adhesive, a release liner on the adhesive layer, and a degradable polymer blocking layer disposed between the adhesive layer and the paper layer that blocks adhesive from bleeding into said paper.

Abstract: A purge dam for retaining a purge gas around a weld zone includes a purge dam structure configured to substantially obstruct an air passage leading to the weld zone. The purge dam includes a main blocking portion configured to substantially block the air passage. The purge dam structure further includes a wall portion configured to engage the air passage for attachment. Adhesive can be optionally provided on the wall portion to facilitate the air passage attachment. Some or all of the purge dam structure may be formed as a multi-layer structure that includes one or more layers of water degradable paper and one or more layers of water degradable polymer. If present, the optional adhesive may be applied to the water degradable polymer layer. The purge dam may be installed by placing the purge dam in the air passage and adhering the wall portion thereto.

Abstract: A welding spacer includes a spacer body having a first pipe-engaging face and a second socket-engaging face. The spacer may be formed from any suitable material, including a liquid-degradable or heat-degradable composition. A spacer thickness separates the first face and the second face. The spacer thickness may comprise solid material or it may have one or more hollow portions. A peripheral edge is provided on the spacer body. One or more deformable members may be provided on the peripheral edge for retaining the spacer in a structure. The welding spacer may be incorporated in a pipe assembly that includes a first pipe segment and a second pipe segment. The first pipe segment has a socket at a first pipe end with an interior shoulder to seat the welding spacer. The second pipe segment has a second pipe end that is received in the socket and seated against the welding spacer.

Abstract: A self-adhesive purge dam for retaining purge gas around a weld zone includes a base configured to substantially obstruct an air passage leading to the weld zone and an adhesive skirt extending from the base and configured to engage portions of the air passage. An adhesive on the adhesive skirt allows the skirt to be adhered to the air passage. An optional removable backing covers the adhesive prior to installation. The adhesive skirt is deployable from a stowed position wherein the adhesive is generally disposed in an interior portion of the purge dam to an installation position wherein the adhesive can be pressed against a surface to which the purge dam is to be adhered. The purge dam can be installed by inserting it in the air passage with the adhesive skirt in the stowed position, removing the removable backing prior to or after insertion in the air passage, exposing the adhesive, and deploying the skirt to the installation position for adhesion.

Abstract: A degradable paper article with long-shelf-life adhesive backing, together with a related fabrication method. The article includes a layer of degradable paper, a layer of degradable pressure sensitive adhesive, a release liner on the adhesive layer, and a degradable polymer blocking layer disposed between the adhesive layer and the paper layer that blocks adhesive from bleeding into said paper.

Abstract: A glass grinding bit includes a monolithic plastic body having a first end, a second end and a central longitudinal axis. A central bore formed as part of the body in alignment with the longitudinal axis for receiving a drive shaft. An outer surface is formed as part of the body in alignment with the longitudinal axis and in concentric relationship with the central bore. A grinding sleeve has an inner surface in permanent interfacial contact with the body outer surface and an abrasive outer grinding surface. A threaded bore in the body extends transversely from the body outer surface to the central bore. A set screw in the transverse bore allows the grinding bit to be secured to a drive shaft.

Abstract: A self-adhesive purge dam for retaining purge gas around a weld zone includes a base configured to substantially obstruct an air passage leading to the weld zone and an adhesive skirt extending from the base and configured to engage portions of the air passage. An adhesive on the adhesive skirt allows the skirt to be adhered to the air passage. An optional removable backing covers the adhesive prior to installation. The purge dam is installed by peeling the removable backing (if present) and exposing the adhesive for adhesion.

Abstract: A self-adhesive purge dam for retaining purge gas around a weld zone includes a base configured to substantially obstruct an air passage leading to the weld zone and an adhesive skirt extending from the base and configured to engage portions of the air passage. An adhesive on the adhesive skirt allows the skirt to be adhered to the air passage. An optional removable backing covers the adhesive prior to installation. The purge dam is installed by peeling the removable backing (if present) and exposing the adhesive for adhesion.