The multilayer antibacterial PAP is a composite pipe of five layers, inside layer is made of special NAMI antibacterial High Density polyethylene HDPE(X), overlapped welded by an aluminum layer, then covered by the outside special HDPE(X), both tightly bonded with melt adhesive to the mid-layer of aluminum core. This newly developed NAMI antibacterial PAP pipe can automatically kill 98% bacterial in the water. It can keep the inside of pipe permanent hygienic and clean, destroy the living environment for bacterial, ensure the water in the pipe clean and safe, improve the quality of drinking water and protect the human life. Therefore, the antibacterial pipe is becoming the new favorite in 21 century and have great market demand in the future. Properties: (1) Healthy and non-toxic, antibacterial and bactericidal, conforming to drinking Water standards (2) Unique and unrivaled German connection technique, convenient and reliable Installation, low construction expenses (3) Excellent heat-insulation property from minimum thermal conductivity (4) Lightweight, convenient to transport and handle, good for labor-saving (5) Smooth inner walls reduce pressure loss and increase flow speed (6) Sound insulation (reduced by 40% compared to galvanized steel pipes) (7) Light colors and excellent design ensure suitability for both exposed and hidden Installation (8) Extremely long usage life for at least 50 years.