Weld purging oil and gas pipelines effectively
Published by Anna Nicklin,
Assistant Editor
World Pipelines,
Weld purging tubes and pipes for the oil and gas industry is crucial when joining metals such as stainless, duplex and chrome steels, as well as nickel alloys, titanium and zirconium. However, when welding larger pipe diameters it is not cost-effective to completely fill tubes and pipes with expensive inert gas.
Huntingdon Fusion Techniques (HFT®) offers QuickPurge® systems that reduce the space that needs to be purged. This, in turn, reduces purging time and leads to vast savings in both time and gas costs.
Ron Sewell, Chairman for HFT said: “Using QuickPurge means that there is no longer a need to fill complete pipes with an inert gas.”
He added: “QuickPurge is simply inserted into a tube or pipe, inflated within the pipe, restricting the area that is to be welded, removing the oxygen down to 100 ppm within minutes.”
For example, a 36 in. dia. stainless steel pipe can be purged down to 100 ppm of oxygen in under 32 min. Comparing this with weld purging using foam dams or other homemade devices that will outgas heavily into the welding zone, which will take many hours.
Some features of QuickPurge Systems include:
- An additional gas input line, allowing extra purge gas to be introduced for higher speed purging down to low oxygen levels. This is particularly useful for larger diameter pipes, where quality welds are required. This cold argon gas input mitigates additional heat that is produced by the plasma/TIG process.
- The advanced design of the QuickPurge system means that oxygen levels as low as 10 ppm can be reached every time, allowing zero colour welds to be achieved with no loss of corrosion resistance caused by oxidation.
- IntaCal® combined with the integrated PurgeGate® device makes it possible to inflate the systems with argon gas safely for sealing, and purging the space between the dams where the weld joint is located. With PurgeGate, any risk of over inflation due to pressure or flow increase is eliminated.
- All systems are manufactured as standard with a hose for connecting a Weld Purge Monitor®, which can read oxygen levels down to as low as 1 ppm (accurate to 10 ppm).
- Materials used in the manufacture of QuickPurge are resistant to higher weld temperatures and they do not outgas, thus preventing weld contamination.
Read the article online at: https://www.worldpipelines.com/product-news/27042017/weld-purging-oil-and-gas-pipelines-effectively/
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