February 16, 2015
For producing zero-color, nonoxidized weld roots, Huntingdon Fusion Techniques Limited HFT® offers PurgExtra™ for the weld purging of tubes and pipes from 1 to 24 in. dia. According to the company, the product complements the PurgElite® series, but also has extra purge gas inlets and corresponding exhaust ports.
Designed for the weld purging of titanium, as well as ultrahigh-purity stainless steel joints, corrosion-resistant alloy welding, and duplex steel joints, the unit allows the operator to purge normally at first and then, when conditions are correct, to introduce additional gas at high flow rates to create a faster purge and a more efficient removal of unwanted gases.
The extra gas flow purges out additional gases as the metal is being heated. The extra gas flow prevents these expelled gases from combining with the hot metal and oxidizing it, which causes the metal to discolor.
The unit comprises two inflatable dams connected by a heat-resistant, flexible gas hose integrated with the IntaCal®II gas release system. This feature allows the dams to be inflated and then releases the inert gas to purge the space between the dams.