Which stripe color identifies Type L copper tube?

Which stripe color identifies Type L copper tube?

• A. Red
• B. Yellow
• C. Blue
• D. Green

Answer: (C)

Blue stripe identifies Type L copper tube. Color coding helps you tell tube types at a glance, with Type K having a green stripe (thickest wall), Type L a blue stripe (mid-wall thickness), and Type M a red stripe (thinnest). This quick identification matters for matching the tubing to the system’s pressure and fitting requirements, so using the blue-stripe tubes ensures you’re using the mid-range Type L appropriate for many domestic water applications. Yellow isn’t a standard color for copper tube type identification in typical practice.

Blue stripe identifies Type L copper tube. Color coding helps you tell tube types at a glance, with Type K having a green stripe (thickest wall), Type L a blue stripe (mid-wall thickness), and Type M a red stripe (thinnest). This quick identification matters for matching the tubing to the system’s pressure and fitting requirements, so using the blue-stripe tubes ensures you’re using the mid-range Type L appropriate for many domestic water applications. Yellow isn’t a standard color for copper tube type identification in typical practice.