Due to the constant upward trends in quality control procedures, there is growing pressure on the process industries to carry out their welding in the absence of oxygen to an ever increasingly lower level. Metals such as stainless steel, titanium, zirconium and nickel alloys are now available to these industries to ensure the greatest strengths, the highest resistance to corrosion and of course the lowest failure rates.
These metals are commonly welded with the GTAW (TIG) process that needs the arc and its surrounding zone to be shielded with a high specification inert gas that has the minimum amount of oxygen. If the welds and their adjacent metal become oxidised, that leads to a lower resistance to corrosion and that has to be prevented.
For this purpose, Weld Purge Monitors® were invented in the 1970s to measure the oxygen levels for welding by Huntingdon Fusion Techniques HFT®. At the time, 100 ppm of oxygen in argon was deemed to be a good level for most stainless steel and other metals, however research shows that it has become necessary these days to try to attain a purity approaching 1 ppm of oxygen in argon when shielding the welds zones in front and behind.
Weld Purge Monitors have been constantly redeveloped to meet changing standards and HFT have now developed an entry level, low cost Weld Purging Monitor, that reads down to 1 ppm, especially for the process industries.
This entry-level model is called the PurgEye® 300 Nano. A customer in the UK recently said: “The PurgEye Nano is really easy to use, with excellent results. The company, which trains TIG welders on stainless steel pipes, enjoys great benefit using it. Previously, each welder would let his inert argon flow as much as possible before starting to weld, to be sure that purging was sufficient. With the PurgEye 300 Nano they know when to reduce the argon flow prior to welding and in such a way they save a significant amount of expensive argon. Any welders and their assistants can use the Nano after only a few minutes of receiving the instructions.”
The PurgEye Nano has been developed for weld purging where data logging, alarms and welder control are not necessarily required. It is small, lightweight and inexpensive. Developed with a unique long life sensor that has the capacity to measure oxygen down to 1 ppm (accurate to 10 ppm), boasting a sensor warm up time under 60 sec.
With leak-tight connectors for weld purge hoses, the PurgEye Nano can be used with optional accessory hand pump and gas sampling probe. It can be used to check purge gas quality from the main source and at the exhaust end of a purging system, as well as to find air leaks in purging hose connections anywhere in a system.
HFT has a Family Range of PurgEye Weld Purge Monitors for every application. The range includes hand held, battery operated monitors and mains powered monitors, which can read oxygen levels from atmospheric concentrate, right down to 1 ppm.
Ron Sewell, Chairman for HFT, said: “All of Huntingdon Fusion Techniques HFT’s Weld Purge Monitors and Inflatable Tube, Pipe and Pipeline Weld Purging Systems are manufactured in the UK. We do not sacrifice on quality. We guarantee to help you achieve zero colour welds, time and time again.”
Read the article online at: https://www.worldpipelines.com/product-news/23032017/hft-develops-new-low-cost-weld-purging-monitor/