When welding or tack welding stainless, duplex, chrome steel and titanium tubes and pipes, it is important to purge the welding zone with an inert gas to prevent corrosion, oxidation, discolouration and to ensure a good internal weld profile with no metallurgical defects.
Huntingdon Fusion Techniques HFT has introduced PurgElite, a range of low cost Tube and Pipe Purging Systems to achieve a clean, oxide free, zero colour weld.
“We recently had a customer who was wasting a lot of money in time and argon gas costs by filling entire pipework fabrications with argon in order to weld the stainless-steel pipes in an inert environment,” Georgia Gascoyne, CEO for HFT said. “There were several 90o bends in the pipework, so the customer thought filling the whole pipework system was the only option.
“To save welders the expense of completely filling tubes and pipes with an inert gas, PurgElite Systems are available, manufactured to suit pipe diameters from 1” to 24” (25 to 600 mm). PurgElite is manufactured with a special spinal tube that is resistant to hot metal up to 300oC (572oF) and is super flexible to allow movement around 180o bends if necessary. These spinal tubes are made of low outgassing rate materials, so there is no risk of weld contamination.”
Each PurgElite features IntaCal, a purge gas feed device, which means there is no complicated valve to adjust and set. A centrepiece glow positioning indicator RootGlo comes as standard to ensure the system can be positioned accurately inside the tube or pipe. In addition, there is no metal braiding on the high temperature resistant gas hose connecting the two inflatable dams, which could be welded to the root of a joint or could scratch the internal bore on removal.
HFT’s innovative PurgeGate Valve is available as an accessory, a unique one way valve suitable for all types of Inflatable Pipe Weld Purging Systems. PurgeGate regulates the gas flow and pressure during weld purging to prevent the dams from over inflating and bursting.
Quick connect/disconnect fittings with collets and ‘O’ ring seals for gas tight sealing, fitted with anti-release circlip are fitted to all Systems to prevent parts accidentally separating inside pipes.
Heat resistant covers with a rating up to a temperature of 300oC are available as accessories to protect the inflatable dams. These are attached with ties sewn into the covers.
There are many fabricators still using homemade devices fashioned from foam, wood, metal and rubber. They are wasting vast amounts of money on expensive argon gas and labour by allowing their welders to continue in their old ways.