In oxyfuel welding in the United States, which statement is true about hose colors?

• A. The fuel hose must be green, and the oxygen hose must be red
• B. The fuel hose must be red, and the oxygen hose must be green
• C. It's not important which hose carries fuel or gas
• D. Both the green and red hoses carry a mixture of oxygen and fuel

Answer: (B)

In oxyfuel welding, color coding of hoses is all about quickly identifying which gas each hose carries to prevent dangerous cross-connection. In the United States, the standard is that the oxygen hose is green and the fuel gas hose is red. This makes it easy to connect the correct hose to the corresponding regulator and torch, and it helps ensure that oxygen (which supports combustion) isn’t mixed or paired with the wrong gas.

So the statement that the fuel hose must be red and the oxygen hose green is the correct one. The other options conflict with the safety convention: reversing the colors would increase the risk of misconnection; saying it doesn’t matter which hose carries fuel or gas ignores a fundamental safety precaution; and claiming both hoses carry a mixture is incorrect because hoses are meant to transport a single gas, not a mixture.