New devices for welding stainless, duplex, chrome steels and titanium are launched by Huntingdon Fusion Techniques HFT®, whose US office is located in Florida. Typically for closure welds, tight bends, T piece joints and dome end connections, where a conventional Tandem Weld Purging System cannot be used, a range of low cost, single ended Inflatable Weld Purge Dams are available for pipe diameters from 6 to 96 inches (150 mm up to 2,440 mm).
The dams are fitted with a dual inflation and purge hose, an additional purge gas hose and an exhaust which can be connected to one of HFTs Weld Purge Monitors. The additional purge gas hose is suitable for providing more inert gas in the event of titanium, zirconium or special stainless applications needing a guaranteed zero color weld. Once the Dam is inflated using the purge gas and seals all around the internal circumference of the pipe, the excess inert purge gas spills out and purges the space around the weld joint. The air (oxygen) is then released out and into the pipe length through a series of venting exhausts on the dam.