... layer of aluminum, the expansion co-efficient a samll metal pipe with considerable strength, toughness, impact resistance.4. Corrosion-resisitant, ... and basin was blocked pipes, the tub-shaped macular rust.5. High temperature, high pressure, in the long-term work ... insulation: thermal conductivity of metal pipes1/200 only, hot water pipe insulation for excellent energy saving effect.7. Light weight, ...