PP-R pipes have lower hardness and rigidity than metal pipes, so they should be protected during handling and construction to avoid mechanical damage from inappropriate external forces. After concealed installation, the pipe locations should be marked to prevent damage during subsequent renovations.
PP-R pipes exhibit some low-temperature brittleness below 5℃, so caution is needed during winter construction. When cutting pipes, use a sharp tool and cut slowly. Do not apply heavy pressure or impact to installed pipes; if necessary, cover vulnerable areas with protective materials.
PP-R pipes are prone to aging and degradation under prolonged ultraviolet radiation. Those installed outdoors or in direct sunlight must be wrapped with a dark protective layer.
Except for mechanical connections such as threaded inserts or flanges when connecting to metal pipes or water appliances, all other connections using PP-R pipes should be heat-fused to ensure a seamless, leak-free system.
PP-R pipes have a relatively high coefficient of linear expansion (0.15mm/m℃). When installing exposed pipes or in concealed (non-direct burial) installations, technical measures must be taken to prevent pipe expansion and deformation.
After installation, pipes must be pressure tested before sealing (direct burial) and covering with a decorative layer (non-direct burial concealed installation). The test pressure for cold water pipes is 1.5 times the system working pressure, but not less than 1 MPa; the test pressure for hot water pipes is twice the working pressure, but not less than 1.5 MPa. The technical specifications stipulate the testing time and methods.
