PP-R PIPE INSTALLATION
PP-R (polypropylene random) tube is also called Type III polypropylene tube, also called random copolymer polypropylene tube or PPR tube. Compared with traditional cast iron pipes, galvanized steel pipes, cement pipes and other pipes, PPR pipes have the advantages of energy saving, environmental protection, light weight and high strength, corrosion resistance, smooth inner wall without scaling, easy construction and maintenance, and long service life. Widely used in construction, municipal, industrial and agricultural fields such as building water supply and drainage, urban and rural water supply and drainage, urban gas, power and optical cable sheathing, industrial fluid transmission, agricultural irrigation and so on.
PPR pipe connection technology:
No water leakage, extremely high reliability. But this is not to say that the PPR water pipe is a defect-free water pipe. The high temperature resistance and pressure resistance are slightly worse. The long-term working temperature cannot exceed 70°C; each section has a limited length and cannot be bent for construction. If the pipeline is laid long or there are many corners, a large number of joints will be used in the construction; the pipe is cheap but the price of the fitting is relatively high. In terms of overall performance, PPR pipes are cost-effective pipes.
Pipe processing temperature
Because polypropylene is a typical crystalline polymer, its melt viscosity is more sensitive to temperature, so the processing temperature control is very important in the extrusion molding of PP-R pipes. The molding temperature is generally controlled at 210~260°C. If the extrusion temperature is too high, it will cause the material to accumulate at the die, which will cause the degradation of the raw materials and reduce the performance of the pipe products.
The main advantage
1. Light weight
Density at 20℃ is 0.90g/cm3, the weight is only one-ninth of the steel pipe, one-tenth of the red copper pipe, light weight, greatly reducing the construction intensity.
2. Good heat resistance
The instant use temperature is 95℃, and the temperature can reach 75℃ in long-term use. It is the most ideal indoor cold and hot water pipeline at present.
3. Corrosion resistance has good thermal insulation performance, when used in hot water system, generally no additional thermal insulation material is needed.
Non-polar materials, have no chemical effect on all ions in water and building chemicals, and will not rust or corrode.
4.Low thermal conductivity
It has good thermal insulation performance. When used in hot water system, generally no additional thermal insulation material is needed.
5. Low pipeline resistance
The smooth inner wall of the pipeline makes the resistance along the way smaller than that of the metal pipeline and lower energy consumption.
6. The pipeline is firmly connected
It has good hot-melt performance. The hot-melt connection connects the pipes and fittings of the same material into a perfect whole, eliminating the hidden danger of water leakage.
7. Hygienic and non-toxic
It has no pollution to the environment during production, construction and use, and belongs to green building materials.
Features
PP-R pipe has the following main features in addition to the characteristics of light weight, corrosion resistance, non-scaling and long service life:
1. Non-toxic and hygienic. The raw material molecules of PP-R are only carbon and hydrogen, and there are no harmful and toxic elements. It is hygienic and reliable. It is not only used for hot and cold water pipes, but also for pure drinking water systems.
2. Heat preservation and energy saving. The thermal conductivity of PP-R pipe is 0.21w/mk, which is only 1/200 of the steel pipe.
3. Good heat resistance. The Vicat softening point of PP-R tube is 131.5℃. The maximum working temperature can reach 95 ℃, which can meet the requirements of the hot water system in the building water supply and drainage specifications.
4. Long service life. The service life of PP-R pipe can reach more than 50 years under the condition of working temperature 70℃ and working pressure (PN) 1.0MPa (provided that the pipe must be S3.2 and S2.5 series or more); at normal temperature (20℃) The service life can reach more than 100 years.
5. Easy installation and reliable connection. PP-R has good welding performance. The pipes and fittings can be connected by hot melt and electric fusion. It is easy to install and the joint is reliable. The strength of the connection part is greater than the strength of the pipe itself.
6. The materials can be recycled. PP-R waste material is cleaned and crushed and recycled for the production of pipes and fittings. The amount of recycled materials does not exceed 10% of the total amount, and does not affect product quality.
Instructions
PPR tube installation tools, including hot-melt tools and cutting tools, such as pressure regulators, electric fuses, heating devices, cutting machines, and integrated tool sets. Selection of heating power for thermal welding tools: usually 700-800W for a pipe with an outer diameter of ≤63mm; 1200-1500W for a pipe with an outer diameter of ≥75mm.
Application field
1. The cold and hot water system of the building, including the central heating system;
2. The heating system in the building, including floor, siding and radiant heating system;
3. Pure drinking water supply system for direct drinking;
4. Central (centralized) air conditioning system;
5. Transportation or discharge of chemical media and other industrial piping systems.
6. Pipe system such as air path for cylinder transmission.
Hot and cold choice
1. Pay attention to the determination of the overall pipeline use coefficient C (that is, the safety factor): General occasions, and long-term continuous temperature ℃, optional C=1.25; on important occasions, and long-term continuous use temperature ≥70℃, and may run at a higher temperature for a longer time, optional C=1.5;
2. For cold water (≤40℃) system, choose P.N1.0～1.6MPa pipes and fittings;For hot water system, choose ≥2.0MPa pipe and fittings.
3. After considering the above three principles, the SDR of the pipe fitting should not be greater than the SDR of the pipe, that is, the wall thickness of the pipe fitting should not be less than the wall thickness of the pipe of the same specification.
Precautions
1. PP-R pipe has lower hardness and lower rigidity than metal pipe. It should be protected during handling and construction to avoid mechanical damage caused by inappropriate external force. After concealed application, the location of the pipeline shall be marked to avoid damage to the pipeline due to secondary decoration.
2. The PP-R pipe has a certain low temperature brittleness below 5℃. Be careful in winter construction. When cutting the pipe, use a sharp knife to cut slowly. The installed pipelines must not be stressed or knocked. If necessary, cover the vulnerable parts with protection.
3. PP-R tubes are prone to aging and degradation when exposed to ultraviolet rays for a long time. It must be covered with a dark protective layer when installed outdoors or in direct sunlight.
4. Besides PP-R pipes being connected with metal pipes or water heaters using mechanical inserts such as threaded inserts or flanges, and the rest should be connected by hot melt to integrate the pipes without leakage points.
5. The coefficient of linear expansion of the PP-R pipe is large (0.15mm/m℃), and technical measures to prevent the expansion and deformation of the pipe must be taken when the pipe is installed directly or not directly buried.
6. After the pipeline is installed, the pressure must be tested before sealing the pipe (directly buried) and covering the decorative layer (not directly buried). The cold water pipe test pressure is 1.5 times the systemworkingpressure, but not less than 1MPa; the hot water pipe test pressure is 2 times the working pressure, but not less than 1.5MPa. It is specified by the technical regulations of pressure test time and method.
