Popularization of PE water supply pipe knowledgePopularization of PE water supply pipe knowledge
PE is an abbreviation of Polyethylene of raised temperature resistance. Generally, the application range of PE pipe water supply pipeline is a temperature below 40 ℃, and it cannot be used for hot water transmission pipeline. PE pipe is a non-polar thermoplastic resin with high crystallinity. The appearance of the original HDPE is milky white, with a certain degree of translucency in the thin section. PE has excellent resistance to most household and industrial chemicals. Certain types of chemicals cause chemical corrosion, such as corrosive oxidants (concentrated nitric acid), aromatic hydrocarbons (xylene) and halogenated hydrocarbons (carbon tetrachloride).
Chinese name PE pipe Foreign name polyethylen Features high crystallinity, non-polar thermoplastic resin color Milky white temperature requirements below 40 ℃ Application life and industry
table of Contents
2 Nano antibacterial
3 Polymerization process
▪ Main features
▪ Product performance
▪ Packaging, storage and transportation
7 PE water supply pipe
8 PE sewage pipe
9 Pipe properties
China's plastic pipes are developing rapidly, and the quality is constantly improving. A plastic pipe industry mainly composed of polyvinyl chloride (PVC-U) pipes, polyethylene (PE) pipes and polypropylene (PP-R) pipes has been initially formed. Among them, polyethylene (PE) pipes are widely used in building water supply, building drainage, buried drainage pipes, building heating, gas transmission and distribution, gas pipelines, electrical and telecommunication protection sleeves, industrial pipes, Agricultural pipes, etc. It is mainly used in urban water supply, urban gas supply and farmland irrigation.
Nano antibacterial PE pipe is to add nano-grade antibacterial masterbatch to the inner plastic of the pipe, and co-extrude it to make the pipe with antibacterial and sanitary self-cleaning effect.
Mainly used in urban water supply network, irrigation diversion project and agricultural sprinkler irrigation project. Since the pipeline connection adopts hot-melt and electric-melt connection, the integration of the interface and the pipe material is realized, and it can effectively resist the one-way stress generated by the internal pressure and the axial impact stress. Moreover, no heavy metal salt stabilizer is added during the production process, the material is non-toxic, non-scaling, and does not breed bacteria, avoiding secondary pollution of drinking water.
◆ Good sanitation, self-cleaning and antibacterial, no scaling in long-term use, which solves the secondary pollution of drinking water.
◆ Resistant to multiple chemical media and no electrochemical corrosion.
◆ The inner wall is smooth, the friction coefficient is low, the medium circulation capacity is correspondingly improved, and it has excellent wear resistance.
◆ Flexibility, high impact strength, strong shock resistance and distortion.
◆ Light weight, convenient transportation and installation.
◆ The connection process is simple, the construction is convenient, and the overall project cost is low.
◆ 50-year service life .
In principle, special resins for high-density polyethylene pipes with a pressure rating of MRS 8 (PE80) can be polymerized by one of several low-pressure polymerization processes. The MRS 10 (PE100) resins for pipes are usually produced by series, bimodal or multimodal polymerization processes.
Bimodal or multimodal polymerization process can customize the polymer to meet the needs of different fields and customers. For new pipe special materials, rigidity, toughness, processing performance and long-term performance are very important. The commonality of all PE100 polymerization processes is the inclusion of at least 2 polymerization reactors in series.
1) Polyethylene (PE) pipes for water supply;
2) Buried polyethylene pipes for gas;
3) HDPE silicon core tube;
4) HDPE cable sheath tube;
5) High density polyethylene pipe;
6) PE buried cable sheath tube;
7) PE perforated tube;
8) HDPE double-wall corrugated pipe.
Classification by density
PE is mainly divided into several different categories based on its density and branching. Its mechanical properties depend on significant variables such as the degree and type of branching, crystal structure and molecular weight. With sales volume, the most important polyethylene grades are high density polyethylene, linear low density polyethylene and low density polyethylene (LDPE).
Ultra high molecular weight polyethylene (UHMWPE)
Ultra low molecular weight polyethylene (ULMWPE or PE-WAX)
High high molecular weight polyethylene (HMWPE)
High density polyethylene (HDPE)
High-density cross-linked polyethylene (HDXLPE)
Cross-linked polyethylene (PEX cross-linked polyethylene)
Medium density polyethylene (MDPE)
Linear low density polyethylene (LLDPE)
Low density polyethylene (LDPE)
Very low density polyethylene (VLDPE)
Chlorinated Polyethylene (CPE) 
High-density polyethylene, the English name is "High Density Polyethylene", referred to as "HDPE". HDPE is a thermoplastic polyolefin produced by copolymerization of ethylene. Although HDPE was introduced in 1956, this plastic has not yet reached a mature level. This universal material is constantly developing its new uses and markets.
The unique characteristics of various grades of HDPE are an appropriate combination of four basic variables: density, molecular weight, molecular weight distribution, and additives. Different catalysts are used to produce customized special performance polymers. These variables are combined to produce HDPE grades for different purposes; the best balance is achieved in performance.
High-density polyethylene is non-toxic, odorless, odorless white particles, melting point is about 130 ℃, relative density is 0.941 ~ 0.960. It has good heat resistance and cold resistance, good chemical stability, high rigidity and toughness, and good mechanical strength. Dielectric properties and resistance to environmental stress cracking are also good.
Packaging, storage and transportation
Keep away from fire and heat insulation during storage. Keep dry and tidy in the warehouse. It is strictly prohibited to mix in any impurities. Sun and rain are strictly prohibited. Transportation should be stored in a clean, dry covered car or ship cabin, without sharp objects such as nails. Mixed transportation with flammable aromatic hydrocarbons, halogenated hydrocarbons and other organic solvents is strictly prohibited.
recycle and re-use
HDPE is the fastest growing part of the plastic recycling market. This is mainly due to its ease of reprocessing, minimal degradation characteristics and its numerous applications in packaging. The main recycling is to use 25% of the recycled materials, such as post-consumer recycling (PCR), and pure HDPE after reprocessing to make bottles that are not in contact with food.
PE pipes for water supply are the replacement products of traditional steel pipes and polyvinyl chloride (PVC) drinking water pipes.
1. PE gas pipe
(1) Reliable connection: the polyethylene pipeline system is connected by electric heat fusion, and the strength of the joint is higher than the strength of the pipeline body.
⑵Good low-temperature impact resistance: The low-temperature embrittlement temperature of polyethylene is extremely low, and it can be safely used in the temperature range of -60-60 ℃. During winter construction, due to the good impact resistance of the material, brittle cracking of the pipe will not occur.
(3) Good resistance to stress cracking: HDPE has low notch sensitivity, high shear strength and excellent scratch resistance, and environmental stress cracking resistance is also very prominent.
⑷Good chemical resistance: HDPE pipelines can resist the corrosion of various chemical media, and the chemical substances present in the soil will not cause any degradation of the pipeline. Polyethylene is an electrical insulator, so it does not rot, rust or electrochemically corrode; it also does not promote the growth of algae, bacteria or fungi.
⑸Aging resistance and long service life: Polyethylene pipes containing 2-2.5% uniformly distributed carbon black can be stored outdoors or used for 50 years without being damaged by ultraviolet radiation.
⑹ Good wear resistance: The comparison test of the wear resistance of HDPE pipe and steel pipe shows that the wear resistance of HDPE pipe is 4 times that of steel pipe. In the field of mud transportation, HDPE pipes have better wear resistance than steel pipes, which means that HDPE pipes have a longer service life and better economy.
⑺ Good flexibility: The flexibility of HDPE pipeline makes it easy to bend. In engineering, it can bypass the obstacle by changing the direction of the pipeline. In many occasions, the flexibility of the pipeline can reduce the amount of pipe fittings and reduce the installation cost.
⑻Convenient handling: HDPE pipes are lighter than concrete pipes, galvanized pipes and steel pipes. It is easy to handle and install. Lower manpower and equipment requirements mean that the installation cost of the project is greatly reduced.
⑼ A variety of new construction methods: HDPE pipelines have a variety of construction techniques. In addition to the traditional excavation methods, a variety of new non-excavation techniques such as pipe jacking, directional drilling, liner, Split pipes and other methods are used for construction, which is a good choice for some places where excavation is not allowed, so HDPE pipeline applications are more extensive.
PE water supply pipe
1. Long service life: Under normal conditions, the minimum service life is up to 50 years.
2. Good sanitation: PE pipes are non-toxic, do not contain heavy metal additives, do not scale, and do not breed bacteria, which greatly solves the problem of secondary pollution of drinking water. It complies with GB / T17219 safety evaluation standards and relevant health safety evaluation regulations of the Ministry of Health.
3. Corrosion resistance of various chemical media: no electrochemical corrosion.
4. The inner wall is smooth, the friction coefficient is extremely low, the passing capacity of the medium is correspondingly improved and it has excellent wear resistance.
5. Good flexibility, high impact strength, strong shock resistance and distortion.
6. Light weight, convenient transportation and installation.
7. The unique electric fusion connection and hot fusion butt connection and hot fusion socket connection technology make the interface strength high and the pipe body, ensuring the safety and reliability of the interface.
8. The welding process is simple, the construction is convenient, and the overall project cost is low.
9. PE environmental protection and health water supply pipes dn20 ~ dn90 are blue, above dn110 are blue or black with blue wire, other colors need to be customized, and the color of accessories corresponds to the color of the pipe.
10. Low water flow resistance: HDPE pipes have a smooth inner surface with a Manning coefficient of 0.009. The smooth performance and non-adhesive properties ensure that HDPE pipes have a higher transport capacity than traditional pipes, while also reducing the pressure loss of pipelines and energy consumption for water delivery.
PE sewage pipe
Sewage PE pipe is also called high-density polyethylene pipe, HDPE in English. This kind of pipe is often used as the first choice for municipal engineering, mainly used in: sewage treatment industry. Because of its wear resistance, acid and corrosion resistance, high temperature resistance and high pressure resistance, it has gradually replaced the traditional pipe materials such as steel pipes and cement pipes in the market, especially because this pipe is lightweight and easy to install and move. It is a new material Preferred. Users should pay special attention to the following points when choosing pipes of this material:
1. Special attention should be paid to the selection of raw materials for plastic pipes. There are thousands of grades of polyethylene raw materials, and there are as low as several thousand yuan a ton of raw materials on the market. The products produced from such raw materials cannot be constructed, otherwise the rework loss will be huge.
2. The selection of pipeline manufacturers shall be subject to formal and professional manufacturers.
3. When you choose to purchase PE pipes, you must conduct on-site inspections of the manufacturers to see if they have production capacity.
1. The hydrostatic strength at 20 ℃ (circumferential stress 9.0MPa, 100h) does not rupture or leak
2. The hydrostatic strength at 80 ℃ (circumferential stress 4.6MPa, 165h) does not rupture or leak;
3. The hydrostatic strength at 80 ℃ (circumferential stress 4.6MPa, 165h) does not rupture or leak;
4. Elongation at break,% ≥350;
5. Oxidation induction time (200 ℃), min ≥20;
6. Longitudinal shrinkage (110 ℃),% ≤3;
7. Weather resistance:
The accumulative hydrostatic strength (circumferential stress 4.6MPa, 165h) of the pipe at 80 ℃ does not rupture or leak. Accepts ≥3.5GJ / m aging fracture shrinkage rate,% ≥350 after energy) induction time (200 ℃), min ≥10 .