Copper tubing is always sized by its?

Copper tubing is sized based on its outer dimension (O.D.), which refers to the overall diameter of the tube. This sizing standard is essential because it allows for consistent fitting with connectors, valves, and other components in a propane system.

In many applications, especially in plumbing and gas distribution systems, knowing the outer dimension is crucial for ensuring that there is adequate space for installation and that the connections are secure. This outer dimension sizing method helps standardize products across the industry, making it easier for professionals to select the appropriate tubing for their needs.

Other dimensions like inner dimension (I.D.) and wall thickness are important for specific calculations related to flow rates and pressure but do not serve as the primary standard for sizing copper tubing in the industry. Length is also a critical factor in many installations, but it does not pertain to the sizing of the tubing itself.