Which material is used as a lining when a pipe is rehabilitated via steam-expanded insertion?

• A. Fiberglass sleeve
• B. PVC liner
• C. Copper tube
• D. Rubber liner

Answer: (B)

Steam-expanded insertion relies on a resin-impregnated fabric liner that is placed inside the damaged pipe and then expanded by heat, usually steam, to press against the host pipe and cure into a new, seamless inner lining. The material used for this lining is typically a fiberglass sleeve, often impregnated with epoxy or resin. The fiberglass sleeve is flexible enough to be inverted or pulled into place and can withstand the heat of the curing process, forming a durable, corrosion-resistant interior that's bonded to the existing pipe. PVC liner, copper tube, and rubber liners aren’t suited to this method: PVC is rigid and doesn’t expand with steam, copper tubes aren’t practical for this interior lining process, and rubber linings don’t provide the same structural resilience or curing compatibility required for steam-assisted CIPP.