1, and the linear expansion coefficient is small: the steady-state linear expansion coefficient of PPR pipe is 1/5 of that of ordinary PP-R pipe, which is close to metal pipe without pipeline.
Obvious thermal expansion and cold contraction. In engineering installation, for the exposed pipeline with horizontal installation length less than 40 meters, the pipeline deformation can be ignored. It has obvious advantages in the application fields of high-temperature hot water, HVAC and outdoor exposed pipeline. practising certificate
Ming: After a long-term cold and hot cycle test, the steady-state steel tube has no deformation or abnormal phenomenon, which fully shows that the steady-state steel tube has stable high temperature resistance.
2. Oxygen-tight and sanitary: Because the steady-state pipe of PPR pipe is covered with alloy aluminum foil on the outer surface of the PP-R inner pipe, the plastic is "penetrated" with a layer of metal armor, which completely isolates the outside air and keeps the fluid in the pipeline system.
The medium is not infiltrated by oxygen and light, which inhibits the growth of algae and ensures the water quality. When PPR pipe is used in central air conditioning system and heating system, it can prevent oxidation and corrosion of metal equipment.
3. Anti-ultraviolet: The steady-state tube of PPR tube is covered with a PP-R protective layer outside the aluminum layer. The aluminum lay can effectively block ultraviolet rays,
PP-R can protect aluminum layer from oxidation, effectively absorb and shield ultraviolet rays, and provide an ultraviolet protective barrier for pipelines. Pipes can be used for outdoor installation and surface-mounted pipeline installation, regardless of anti-ultraviolet measures, so that
With longer service life, it is an ideal choice for outdoor construction of solar and thermal energy systems.
4. High compressive strength and good temperature resistance: Compared with other pipes, PPR pipes have good compressive properties and certain metal properties in terms of long-term strength. Due to the addition of the metal layer, the rigidity of the pipe is increased, and the creep of the pipe is reduced, thus enhancing the compressive strength and temperature resistance of the pipe.
Matters needing attention in PPR pipeline construction:
1, PPR pipe has lower hardness and stiffness than metal pipe, so it should be protected during handling and construction to avoid mechanical damage caused by improper external force. Mark the location of the pipeline after dark application, so as to avoid damage to the pipeline by secondary decoration.
2.PPR pipe is brittle at low temperature below 5℃, so be careful in winter construction, and slowly cut the pipe with a sharp knife. Don't squeeze or knock the installed pipeline, and cover the parts vulnerable to external force when necessary.
3.PPR tubes are prone to aging and degradation due to long-term exposure to ultraviolet rays, and must be wrapped with a dark protective layer when installed outdoors or in direct sunlight.
4. In addition to mechanical connection methods such as threaded inserts or flanges, PPR pipes should be connected by hot melt, so that the pipes can be integrated without leakage points.
5. The linear expansion coefficient of 5.PPR pipe is relatively large (0. 1.5 mm/m℃), so technical measures must be taken to prevent the expansion and deformation of the pipe when it is laid in TD or buried.
6. After pipeline installation, pressure test must be conducted before sealing the pipeline (directly buried) and covering the decorative layer (not directly buried). The pressure test pressure of the cold water pipe is 1.5 times of the working pressure of the system, but not less than/10 MPa；; The test pressure of the hot water pipe is twice the working pressure, but not less than 1.5MPa. The time and method of pressure test are specified in the technical specification.
7. When PPR pipes are exposed or buried underground, supports and hangers must be installed as required.