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 from Huntingdon Fusion Techniques HFT®.
Manufactured for pipe diameters from 6 to 96 inches (150 mm up to 2,440 mm), these lightweight systems are easy to inflate using the purge gas. Once the Dam is inflated 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 which then pushes the air out to the open atmosphere. Each Dam is equipped with a purge/inflation hose (black), an extra purge gas hose (blue) as well as a hose for connecting a Weld Purge Monitor® (red).
The blue hose is suitable for passing extra gas into the weld zone at any time to cool welds to meet interpass specifications, or to provide extra inert gas in the event of titanium, zirconium or special stainless applications needing a guaranteed zero colour weld. By producing bright shiny welds, there will be no porosity and there will be no loss of corrosion resistance caused by oxidation.