Final answer:
The part of a piping system that conveys gas to appliances is called a branch line. It differentiates from other system components like an air conditioner's condenser, which converts gas to liquid. Gas typically moves from high pressure to low pressure areas.
Step-by-step explanation:
The part of a piping or tubing system which conveys gas from the main supply piping, tubing, or header to an appliance is known as a branch line. This is not to be confused with the other components of systems, such as an air conditioner, where the condenser is responsible for converting gas into liquid, or the evaporator, which does the opposite by converting liquid refrigerant into gas. Additionally, it's worth noting that in the context of physics and fluid dynamics, gas moves from an area of high pressure to an area of low pressure.