Advantages and Disadvantages of PE Pipe, PPR Pipe and PVC Pipeline and Their Com
Date:2019-09-27 11:00:59 From: Times:
Advantages and Disadvantages of PE Pipe, PPR Pipe and PVC Pipeline and Their Comparison in Water Supply System
With the development of science and technology, the petrochemical industry has developed rapidly. In engineering, more and more industries in the water supply and drainage systems use plastic pipes instead of conventionally used cast iron pipes, galvanized pipes, and plastic-lined steel pipes. Compared with traditional pipes, plastic pipes have the advantages of light weight, corrosion resistance, low water flow resistance, energy saving, simple and quick installation, and low cost, which are favored by the pipeline engineering community. Moreover, plastic pipe has made great progress in the design theory and construction technology of the building, and accumulated rich practical experience, which has promoted the plastic pipe to occupy a very important position in the construction of water supply and drainage pipeline engineering, and Form an unstoppable development trend.
First, three materials material composition, parameter analysis
▲PE pipe: polyethylene, the English name "polythylene" referred to as PE, is a thermoplastic resin obtained by polymerization of ethylene, with excellent resistance to industrial chemicals. According to the long-term hydrostatic strength of PE pipe, the pipe and its raw materials are strictly classified into five grades: PE32, PE40, PE63, PE80 and PE100. Both PE80 and PE100 are used in water and natural gas systems to produce large diameter pipes. The pressure rating is 0 to 1.0 MPa.
▲ PVC pipe: PVC, the full name is "Polyvinylchlorid", referred to as PVC, the main component is polyvinyl chloride, and other ingredients to enhance its heat resistance, toughness, ductility and so on. Its specifications range from De16 to De630, which are divided into three types: water supply, sewage, and threading. The pressure rating is 0 to 1.6 MPa.
▲PPR pipe: the full name of the type III random polypropylene tube, a copolymer of propylene monomer Propylene and ethylene monomer Ethene (Poly Propylene Random Copolymer), is a new type of international level in the 1990s. Energy-saving and environmentally friendly plastic products. PPR pipe is a new material. Its specifications range from De20 to De110, using water supply, hot water, and pure drinking water. The pressure rating is 0 to 2.5 MPa.
Second, the advantages and commonalities of the three materials.
(1) Advantages of PPR water supply pipe
In addition to the characteristics of light plastic material, good strength, corrosion resistance and long service life, PP-R pipe is also non-toxic due to its own characteristics (the molecule contains only two elements of hydrocarbon and does not cause damage to the human body. Any poisonous and auxiliary use is a well-deserved environmental health material), no rust, no scaling (smooth inner and outer walls, strong corrosion resistance, and little flow resistance to flowing liquid) heat resistance, antifreeze, heat preservation The waste can be recycled and used. Therefore, it can be used as a hot and cold water pipe, a pure water pipe and a drinking water pipe, etc., and has the following main features:
1 heat-resistant, heat-insulating, is an energy-saving product. PP-R tube Vicat softening temperature is 131.3 ° C, the maximum use temperature is 95 ° C, long-term (50 years) use temperature is 70 ° C. The thermal conductivity of the product is 0.24W / m ° C, only 1 / 2 thermal conductivity of steel 200, for hot water pipe insulation energy saving effect is excellent;
2 It is convenient and reliable to install. It adopts hot-melt connection and can complete a joint connection in a few seconds. It is connected with metal pipe and water machine with high-quality metal nickel-plated inserts, which is safe and reliable.
3 easy to recycle.
(2) PE water supply pipe advantages
1PE pipe material is non-toxic, non-corrosive, non-fouling, can effectively improve the water quality of the pipe network; chemical corrosion resistance, resistance to internal, external and microbial corrosion, strong corrosion resistance, health; PE pipe has good water hammer resistance The ability to integrate the pipe joint with the pipe and the PE pipe to effectively resist the underground movement and end load greatly improve the safety and reliability of the water supply.
2 Easy to match welding and electrofusion welding to form a closed anti-seepage system. When laying along the groove, the amount of earthwork for trench excavation can be reduced and the amount of accessories can be reduced.
3 light weight and easy to install; pipe angle can be arbitrarily processed.
4 Strong wear resistance and excellent hydraulicity, no need for outer protection in buried pipelines. It can be applied to earthquake and mining area settlements, and can also be laid at the bottom of rivers by sinking method.
6 good environmental adaptability and frost resistance. Can be used for indoor and outdoor water supply pipes.
7 long service life, with a service life of more than 50 years;
8 easy to recycle.
(3) Advantages of PVC piping
1 In the production of general-purpose resin, PVC resin consumes the lowest amount of ethylene and has the lowest production cost. Domestic production of PVC per ton of PVC requires 0.5314 tons, while the average consumption of ethylene per ton of polyethylene is 1.042 tons. The ethylene consumption per ton of PVC resin in China is about 50% less than that of polyethylene. The production of chlorine, a raw material for PVC, is an important way to balance the production of chlorine by caustic soda. Caustic soda is an essential raw material for the national economy. In addition, from the perspective of plastic products, PVC has good compatibility with various additives, and a large amount of low-cost filler can be added to the production pipe, which greatly reduces the production cost.
2PVC pipe has good mechanical properties, and has excellent corrosion resistance. It is light in weight, easy to install, requires no maintenance, and works well on PVC pipes with a service life of up to 50 years. Therefore, PVC pipe is a good plastic product with low production cost, high strength and corrosion resistance.
3 connection method - bonding, convenient and fast.
4 easy to recycle.
All three materials can be used in living water supply systems, process circulating water systems, and general water supply systems.
Third, the comparison of the shortcomings of the three materials.
(1) Disadvantages of PPR water supply pipeline
1 There are few pipe specifications and accessories. The types of accessories and valves are not complete, and there is a problem of inconvenient connection with the metal door. Large gauge pipes currently have the largest Dn160, no larger specifications. It is greatly affected by temperature.
2 Rigidity and impact resistance are worse than metal pipes and are easily damaged.
3 The linear expansion coefficient of the pipe is large.
4 poor UV resistance. In the long-term exposure of the sun, the PPR pipe is prone to aging and reduces the service life.
(2) PE disadvantages:
1 PE is expensive, and the pipe is now acceptable with constant promotion prices, but the price of pipe fittings is still too high.
2 PE cannot be used in hot water pipe networks.
3 The hot melt welding requires a large pressure and a long cooling time.
4 exposed to outdoor sunlight is easy to age.
(3) PVC pipe defects:
1 There are few pipe specifications and accessories. The types of accessories and valves are not complete, and there is a problem of inconvenient connection with the metal door.
2 Rigidity and impact resistance are worse than metal pipes and are easily damaged.
3 Buried connection has low pressure resistance and is easy to break.
These three types of pipes are widely used in water supply systems (fire-fed water supply systems use steel skeleton plastic composite pipes), and PPR pipes can be used for hot water pipes. The outdoor large-diameter water supply network uses PE pipes.
Four, three types of pipe connection comparison
●PE: When DN≤63, it adopts injection molding hot-melt socket connection or hot-melt butt joint; when DN≥75, it adopts hot-melt butt joint or electrofusion socket connection; when connecting with different materials, it adopts flange or thread connection.
●PPR: It adopts injection molding hot melt socket connection; it is connected by flange or thread when connecting with different materials.
● PVC: It is made of special adhesive for bonding and bonding. When connecting with different materials, it is connected by flange or thread.
When the pipe diameter is greater than or equal to 75 mm, PE should be used in terms of cost (high pipe fitting price). Outdoor pipes generally have large pipe diameters, so PE is mainly used for outdoor pipe networks.
Five, three aspects of pipe aesthetics comparison
◆PE is mainly black and black with blue stripes on the market today (with UV resistance).
◆ PPR is mainly white and gray on the market today.
◆ PVC is mainly white and blue in the market today.
From the perspective of visual aesthetics, PPR pipes or PVC pipes should be used for indoor pipes.
The outdoor water supply network uses PE pipes, the indoor water supply pipes and hot water pipe networks use PPR pipes, and the indoor cold water can use PVC pipes.