Before installing copper tubing for a natural gas line, you may want to consider all optional pipe materials. The type of pipe you use will depend on variable factors you should consider:
Copper - Use is limited to Types K and L and others that are approved
Steel - these pipes are normally used indoors, due to possible corrosion.
Yellow Brass - Typically approved for indoor use.
Aluminum - limited approval for indoor use.
PVC - Lower cost and typically approved for outdoor use.
PE (Polyvinyl Chloride) Low cost and used for outdoor applications, uses flexible connectors.
Ductile iron - Limited approval for use in outdoor applications.