What materials are acceptable for gas piping in residential applications?

In residential applications, the materials typically accepted for gas piping include black iron, copper, and flexible corrugated stainless steel tubing.

Black iron piping is a standard choice for natural gas and propane systems due to its durability and ability to withstand high pressures. It is also resistant to corrosion in typical gas environments when properly maintained.

Copper is another widely used material for gas piping, especially in residential settings. It has good resistance to corrosion and is also relatively easy to work with. However, it's important to note that there are specific guidelines regarding the use of copper with certain gases, so compliance with local codes is necessary.

Flexible corrugated stainless steel tubing is increasingly popular because of its flexibility and ease of installation. This type of piping can accommodate changes in direction and can be installed with fewer joints, reducing the likelihood of leaks.

The other materials listed in the question are not suitable for gas piping in residential applications. Plastic and aluminum do not meet the safety and durability standards required for gas, while rubber and PVC are unsuitable due to their inability to handle the pressure and potential chemical reactions with gas. Lead and galvanized steel are also not acceptable choices; lead poses significant health risks, and galvanized steel does not provide the necessary integrity for gas delivery systems.