What is defined as the gas piping from the supply main or major branch to an appliance?

The term that accurately describes the gas piping from the supply main or major branch to an appliance is a branch line. This type of piping extends from the larger supply lines to deliver gas directly to individual appliances. Understanding this concept is essential in gas systems design, as the branch line is crucial for ensuring that each appliance receives a sufficient and appropriate supply of gas for safe and efficient operation.

In the context of gas systems, the main line typically refers to the primary pipeline that brings gas from the source to various distribution points. The service line usually refers to the line that connects the utility's gas supply to the consumer's piping system. A drop line is specifically a term often used to indicate a vertical run of piping that typically connects a higher line to an appliance located at a lower level. Thus, the branch line is specifically designated for connecting larger supply lines to the appliances, marking it as the correct answer.