What type of piping is typically used for gas distribution?

Steel and polyethylene (PE) are commonly used materials for gas distribution piping because of their favorable properties for this application. Steel is strong and durable, making it suitable for high-pressure gas lines, while PE is lightweight, resistant to corrosion, and flexible, making it ideal for underground installations where the pipes need to withstand soil movement and moisture without degrading.

Polyvinyl chloride (PVC) is not suitable for gas distribution due to its inability to handle the high pressures and temperatures associated with gas lines, as well as its susceptibility to stress cracking. Cast iron was historically used for gas distribution but has fallen out of favor due to its weight, brittleness, and susceptibility to corrosion over time. Copper can be used in some gas applications, particularly for small-scale residential connections, but it is not the predominant material used for larger gas distribution systems. For these reasons, the most appropriate and widely accepted choices for gas distribution piping are steel and PE, making this answer correct.