Skip to main content

Welder Red Seal · Question

A welder is setting up to GTAW an open root butt joint on 2.0 mm thick 304 stainless steel tubing. Which of the following purging methods would be most effective and economical for a single, small diameter tube?

For small diameter tubing, creating a localized purge chamber using an insoluble purge dam (like water-soluble paper or commercial expandable plugs) to contain

Start free practice for Welder Red Seal

154 questions · no signup required · 40 free questions per day

Start Practice →

Question: A welder is setting up to GTAW an open root butt joint on 2.0 mm thick 304 stainless steel tubing. Which of the following purging methods would be most effective and economical for a single, small diameter tube?

Answer options:

  • Backing with a copper chill bar. ✅ Using a homemade purge dam with insoluble paper and an inert gas.
  • Flooding the entire working area with argon.
  • Applying a flux paste to the root of the weld.

Correct answer: Using a homemade purge dam with insoluble paper and an inert gas.

Explanation: For small diameter tubing, creating a localized purge chamber using an insoluble purge dam (like water-soluble paper or commercial expandable plugs) to contain the inert gas (e.g., argon) is both effective at preventing oxidation and economical as it conserves gas. Copper chill bars absorb heat but don't prevent oxidation, and flooding large areas is wasteful.

Start free practice for Welder Red Seal

154 questions · no signup required · 40 free questions per day

Start Practice →

More about Welder Red Seal

Related Questions

More for Welder Red Seal candidates

Ready to practice?

Free, no signup required. Build a wrong-question list as you go.

Start Free Welder Red Seal Practice →

Related courses

Other Canadian certifications candidates often prepare for alongside this one.