Weld purging a variety of pipes of different diameters can be complex and costly, particularly when having to fill pipework systems with expensive argon gas.
One solution that welders have traditionally devised has been to construct homemade foam or paper dams that are placed on either side of the weld in order to constrict the purge volume and make weld purging times shorter.
However, homemade foam or paper purge dams have severe technical limitations that can lead to loss of welds when they leak or slip from position thus flooding the welding zone with oxygen.
To overcome these challenges Huntingdon Fusion Techniques (HFT®) has designed and developed Argweld® Weld Purge Film® kits to make weld purging affordable and successful.
The Weld Purge Film kits can be used on pipe diameters up to 900 mm (36 in.) and for temperatures up to 300ºC (572ºF) without the material burning and losing the weld purge.
These low costk save operators high costs by minimising gas usage and dramatically reducing the time taken to make a purge. They have been designed and developed by HFT, containing the product accessories required to manufacture dams that will not come loose during welding.
The technical advantages of using water soluble film instead of other materials include:
- Total transparency of the film dams, allows the welder to see the weld root as it is being laid.
- Vapour pressure of the film is very low and does not outgas harmful elements during welding that can mix with the hot metal and cause metallurgical defects.
- The Argweld film does not contain water like paper and sponge products do.
After welding, the water soluble film is simply washed away during the standard hydrotest cycle or by flushing of the pipe interior and dissolved down to molecular level, leaving no trace.
Read the article online at: https://www.worldpipelines.com/product-news/16022017/hft-welcomes-weld-purging-tools/