What size tubing should be installed for a gas line that is 520 feet long and uses semi-rigid Type K copper tubing?

For a gas line that is 520 feet long using semi-rigid Type K copper tubing, the correct size is determined by considering factors such as the length of the run, the type of gas being transported (like natural gas or propane), and the flow rate requirements.

In this scenario, larger diameter tubing minimizes pressure drop across long distances. Type K copper tubing is a common choice for gas installations because of its strength and durability, but the size must sufficiently accommodate the necessary flow rate and pressure characteristics.

Considering the information provided and industry standards, a diameter of 1-1/2 inches is typically suitable for a longer gas line run such as 520 feet. This size strikes a balance by ensuring adequate flow without excessive pressure loss, which could occur if a smaller diameter were selected.

Larger sizes such as 2 inches would be unnecessary for standard residential or commercial uses, leading to unnecessary costs and complications. Thus, while examining the options, 1-1/2 inches provides the most appropriate and efficient solution for this particular gas line configuration.