Steady State PP-R Aluminum attached PP-R pipe combines advantages of normal PP-R pipe and metal pipe. Small linear expansion, oxygen permeation free. Features: 1. Small linear expansion. Jiuhao aluminum-plastic steady PP-R pipes’ linear expansion is 1/5 of normal ppr which is close to metal material; no obviouse expansion with heat or contraction with cold during installation. Therefore, Jiuhao aluminum-plastic steady PP-R pipes have obviouse advantages under high temperature, for hot water, heating ventilation(HVAC) or outdoor installation 2. Aluminum layer isolate external air, keeps no oxygen infiltrate, ideal for central air conditioning, heating system, can prevent oxidation and corrosion of metal parts, inhibit germs, ensure hygiene of pipes. 3. Anti-Uv rays, ppr layer protect aluminum from oxidation, inner aluminum layer can isolate uv ray, can be used for outdoor installation, do not need special protection, long term using life, ideal for solar energy, heating system or reconstruction. 4. Stand static pressure. Compare with normal PP-R pipes, Jiuhao aluminum-plastic steady PP-R pipes can bear higher pressure, aluminum layer increases strength of pipes. All design of PP-R pipes inner layer sizes are based on national standard. 5. Reliable connection and high level of safety. Before connecting with special peeler stripped the outside two layers, then connect inner layer with the same material PP-R pipe by meilting connection. 6. Inner metal layer can be detectived easily. Easier to find a suitable position towards the end of the construction period without destroy the original pipes Applications: can be used under high temperature, hot water, heating ventilation(HVAC), outdoor installation, central air-conditioning system, solar energy, high temperature radiator and reconstruction etc..