Water soluble film makes good purge barrier

摘要

Creating a controlled environment around a weld inside a pipe or tube can be a problematic process but using water-soluble plastic film as a purge barrier contributes to better efficiency and overall cost effectiveness. Darren Sewell, Managing Director of Huntingdon Fusion Techniques, discusses the options. In today's cost driven world, it is ever more desirable for installation and facility managers to employ techniques and materials that contribute to better safety and are more environmentally friendly. It goes almost without saying that operating costs have to be cut at the same time - and quality improved! In the specialised but now widespread field of stainless steel or titanium welding, particularly in pipes and tubes, repeatable and clean, strong welds are critical. Several disciplines are involved in achieving this, including weld purging, or the control of environmental oxygen levels around the weld in order that the finished join is free from coking, cracking and porosity, or preventing uneven penetration of the weld material. In order to retain the purge gas in place, a variety of means can be deployed and, increasingly, operators are using barriers that are readily soluble and can be flushed from the system once the welds are complete.