TPT July 2018

AR T I C L E

Huntingdon Fusion Techniques Ltd

The QuickPurge ® Family of inflatable tube, pipe and pipeline systems have been designed for pipe welding between 6 and 88" (150 and 2,235mm). Both PurgElite ® and QuickPurge ® products are multi-use systems and include high temperature options for pre- and post-weld operations up to 300°C. Weld Trailing Shields ® Expandable plugs and inflatable purge systems meet the requirements for protection of the weld root during tube and pipe welding: trailing shields are available for the topside. They can provide a high level of additional inert gas shielding to supplement that supplied by the basic welding torch. Shields are available to match a wide variety of forms, from flat to diameters as small as 25mm. Both internal and external models are available. Flexible Welding Enclosures ® For component welding, Flexible Enclosures overcome all the disadvantages of glove boxes and vacuum systems but at a fraction of the cost. They occupy considerably less floor space and all parts of the welded component finish bright and shiny with no oxidation or discolouration. Argon gas costs are reduced significantly and cleaning costs are eliminated. Controlling purge gas quality Using specialised weld purging equipment does not guarantee defect-free welds. Control of the oxygen content of the purge gas is crucial to success, and a monitor that measures residual oxygen content reliably and accurately at the low levels considered is necessary when welding zirconium alloys. These instruments are capable of measuring oxygen content accurately as low as ten ppm, more than adequate to satisfy the residual oxygen recommended for zirconium alloy welding.

surfaces. Post weld cleaning to remove these undesirable contaminants can be time-consuming and expensive.

Controlling purge gas coverage A wide range of ancillary equipment is available specifically to ensure optimised coverage of the weld zone with inert purge gas. From simple expandable plugs to fully integrated inflatable devices, the products can accommodate pipe sizes from 10 to 2,500mm. Expandable Plugs are a popular choice and these are available with nylon, steel and aluminium bodies. Surrounding each body is a flexible seal that can be expanded by applying a radial force through a manually operated wing nut on the shaft. These mechanical plugs can be used for purging pipework fabrications where a variety of openings are present and where it is easier to purge the complete assembly. Inflatable Weld Purging Systems have been developed to help speed up the welding process for engineers involved in the fabrication of pipes and tubes. The PurgElite ® range, manufactured by Huntingdon Fusion Techniques, is a robust, easy-to-use welding ancillary that offers considerable savings in time and inert gas. Two inflatable dams are connected by a synthetic flexible hose that will not scratch the inside of polished tube or pipe work. The hose is made of a self-sealing intumescent material that resists even hot metal being dropped on it and will not disturb the purge gas flow.

Huntingdon Fusion Techniques Limited 
– UK Fax: +44 1 554 836 837

Email: hft@huntingdonfusion.com Website: www.huntingdonfusion.com

Figure 2: The most efficient method of ensuring high quality inert gas coverage is to use flexible enclosures. They are available in sizes approaching 30 cubic metres with residual oxygen content as low as ten parts per million

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JULY 2018