Which of the following is a piping material used for gas piping in residential installations?

• A. Copper tubing
• B. CSST (corrugated stainless steel tubing)
• C. PVC pipe
• D. PEX tubing

Answer: (B)

CSST (corrugated stainless steel tubing) is used for gas piping in many residential installations because its flexible, lightweight tubing makes it easier to route gas lines through walls, ceilings, and around obstacles with fewer joints than rigid metal pipe. It provides a reliable gas supply for natural gas and propane when installed with the proper fittings and protective jacket, and it is designed to meet typical residential codes. A key safety requirement is bonding the gas piping to the building’s electrical grounding system to prevent stray electrical energy from igniting gas. Copper tubing is used in some cases, but CSST’s flexibility is a major advantage; PVC isn’t used for gas piping, and PEX is not standard for residential gas piping.