How do argon and helium flow rates compare?

• A. Helium flows at 30-50 CFH; argon flows at 15-35 CFH
• B. Argon flows at 30-50 CFH; helium flows at 15-35 CFH
• C. Both gases flow at the same rate
• D. Helium flows at 15-25 CFH; argon at 25-45 CFH

Answer: (A)

Shielding gas flow rates are chosen based on how the gas behaves around the weld. Helium is lighter and diffuses away more easily than argon, and it also has higher thermal conductivity, which can push the shielding gas away from the weld area. Because of this, you typically need a higher flow to maintain a stable shield with helium than with argon. The practical ranges reflecting this are helium around 30–50 CFH and argon around 15–35 CFH. So the option that lists helium in the 30–50 CFH range and argon in the 15–35 CFH range aligns with how these gases behave and how welders set their shielding in practice.