According to B31.5, soft drawn copper tubing larger than what diameter shall not be used?

The guidance provided by B31.5 regarding the use of soft drawn copper tubing emphasizes that this type of tubing should not be used when the diameter exceeds 1 3/8 inches. The reasoning behind this limitation is based on the structural integrity and performance of soft drawn copper in high-pressure applications. As the diameter increases, soft drawn copper's ability to withstand pressure without deforming or compromising the system decreases significantly.

Tubing smaller than 1 3/8 inches retains sufficient strength and flexibility for typical applications, allowing for reliable performance. The specifications in B31.5 are designed to ensure safety and efficiency in piping systems, which is essential, especially in pressurized environments. Thus, adhering to this guideline helps prevent potential failures that could arise from using inappropriate materials for larger diameter piping.