0 ITEM
The advantages and disadvantages of PE, PPR and PVC and their application
With the development of science and technology, the rapid development of petrochemical industry, in the engineering of water supply, drainage system in more and more industries to use plastic pipe to replace the conventional use of cast iron pipe, galvanized pipe, lined plastic steel pipe and other materials.
Plastic pipe and traditional pipe compared, with light weight, corrosion resistance, water resistance is small, energy saving, simple and rapid installation, low cost of significant advantages, by the pipeline engineering circle.
Moreover, the plastic pipe in the construction of the design theory and construction technology has made great progress and perfect, and accumulated rich practical experience, make the plastic pipe in the construction of water supply and drainage pipe engineering occupy a very important position, and form an irresistible trend of development.
Material composition and parameter analysis of three kinds of materials
Perspace: Polyethylene, which is a thermoplastic resin made by the polymerization of ethylene, has 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.
PE80 and PE100 specifications are mainly used for water supply and natural gas systems, which can produce large diameter pipelines.
The pressure grade is 0 ~ 1.0mpa.
PVC pipe: PVC, full name is "Polyvinylchlorid", PVC for short, mainly composed of polyvinyl chloride, other ingredients are added to enhance its heat resistance, toughness, ductility and so on.
Its specifications from De16 to De630, divided into water, water, threading pipe three.
The pressure grade is 0 ~ 1.6mpa.
PPR pipe (full name: type III atactic polypropylene pipe) is a Poly Random Copolymer polymerized from Propylene monomer and Ethene, which is a new type of energy-saving and environment-friendly plastic product with international standards in the 1990s.
PPR pipe as a new material.
Its specifications from De20 to De110, used for domestic water supply, hot water, pure drinking water engineering.
The pressure grade is 0 ~ 2.5mpa.
The advantages and common points of two or three materials
(1) ADVANTAGES of PPR water supply pipeline
Pp-r pipe in addition to good with general plastic pipe material is qualitative light, intensity, corrosion resistance, long service life characteristics, also due to the nature of itself has a non-toxic (molecules containing hydrocarbon only two elements, won't cause any adverse to human body, is worthy of healthy environmental protection material), does not rust, does not scale (inside and outside the wall smooth,
Has strong corrosion resistance, and has little flow resistance to flowing liquid) heat resistance, anti-freezing, heat preservation, waste can be recycled and other advantages, therefore, can be used as cold and hot water pipes, pure water pipes and drinking water pipes, but also has the following main characteristics:
Heat resistance, heat preservation, energy-saving products.
Pp-r tube vicka softening temperature is 131.3℃, the highest service temperature is 95℃, long-term (50 years) service temperature is 70℃.
The thermal conductivity of the product is 0.24W/m℃, only 1/200 of the thermal conductivity of steel pipe, used for hot water pipe insulation and energy saving effect is excellent;
(2) Easy and reliable installation, hot melt connection, a few seconds to complete a joint connection, and metal pipe and water pipe connection with high quality metal plated nickel insert, safe and reliable.
Easy to recycle and use
(2) ADVANTAGES of PE water supply pipeline
(1) PE pipe material is non-toxic, non-corrosive, non-scaling, which can effectively improve the water quality of pipe network;
Chemical corrosion resistance, internal, external and microbial corrosion resistance, strong corrosion resistance, with health;
PE pipe has good resistance to water hammer pressure, and the fusion joint of pipe and PE pipe have effective resistance to underground movement and end load, which greatly improves the safety and reliability of water supply.
(2) Easy to pair welding and electric fusion welding to form a closed anti-seepage system.
When laying along the trench, the earthwork amount of trench excavation and the amount of accessories can be reduced.
Light weight and easy to install and handle;
Angle of pipe fittings can be processed arbitrarily.
④ Strong wear resistance and excellent hydraulic properties, in the buried pipeline without outer protection.
It can be applied to earthquake and subsidence area of mining soil layer, and can also be laid in river bottom by sinking method.
Good environmental adaptability and frost resistance.
Can be used for indoor and outdoor water supply pipeline.
⑦ Long service life, with more than 50 years of service life;
⑧ easy to recycle.
(3) the advantages of PVC pipe
① In the production of universal resin, PVC resin has the lowest ethylene consumption and the lowest production cost.
Domestic production per ton of PVC consumption of 0.5314 tons of ethylene, and per ton of polyethylene average consumption of 1.042 tons of ethylene, domestic per ton of PVC resin consumption of ethylene than polyethylene consumption of about 50%.
The production of PVC raw material chlorine, is an important way to balance the production of caustic soda chlorine, caustic soda is essential to the national economy is very important raw materials.
In addition, from the point of view of plastic products, PVC and all kinds of good compatibility of additives, in the production of pipes can join a large number of low filler, so that the production cost is greatly reduced.
PVC pipe has good mechanical properties, and has excellent corrosion resistance, light weight in the use process, easy installation, no need to maintain, the role of good processing PVC pipe, service life of up to 50 years, etc..
Therefore, PVC pipe is a good plastic products with low production cost, high strength and corrosion resistance.
Connection mode -- bonding, convenient and quick.
④ Easy to recycle and use.
All three materials can be used in domestic water supply system, process circulating water system and general water supply system.
Three, three kinds of material shortcomings comparison
(1) SHORTCOMINGS of PPR water supply pipeline
(1) Few pipe specifications and fittings.
Accessories and valve types are not complete, and there are inconvenient problems to connect with the metal door.
At present, the largest size of large size pipe is Dn160, there is no larger specification.
Affected by temperature changes greatly.
(2) The rigidity and impact resistance is worse than the metal pipe, easy to be damaged.
The linear expansion coefficient of pipe is large.
4. Poor uv resistance.
In the long time of sunlight and ultraviolet environment, PPR pipe is easy to aging, reducing the service life.
(2) DISADVANTAGES of PE:
(1) PE cost is high, the price of pipe is now acceptable with the continuous promotion, but the price of pipe fittings is still too high.
PE can not be used for hot water pipe network.
(3) High pressure and long cooling time are required for hot melt welding.
④ Exposed in the outdoor sun is easy to aging.
(3) PVC pipe shortcomings:
(1) Few pipe specifications and fittings.
Accessories and valve types are not complete, and there are inconvenient problems to connect with the metal door.
(2) The rigidity and impact resistance is worse than the metal pipe, easy to be damaged.
③ The compressive strength of buried connection is slightly lower and easy to fracture.
The three kinds of pipes mentioned above are widely used in water supply systems (fire supply systems use steel frame plastic composite pipes), PPR pipes can be used for hot water pipes.
PE pipe is used for outdoor large diameter water supply network.
Four, three kinds of pipe connection method comparison
PE: DN≤63, using injection hot melt socket connection or hot melt butt;
When DN≥75, use hot melt butt connection or electric fuse socket connection;
When connecting with different materials, flange or thread connection is used.
PPR: injection molding hot melt socket connection;
When connecting with different materials, flange or thread connection is used.
PVC: use special adhesive socket bonding, flange or thread connection when connecting with different materials.
When the pipe diameter is greater than or equal to 75mm, PE should be used in terms of cost (the price of pipe fittings is high).
Outdoor pipe diameter is generally large, so PE is mainly used for outdoor pipe network.
Five, three kinds of pipe aesthetic comparison
PE is mainly black and black with blue stripes (with anti-uv function) on the market today.
PPR is now marketed mainly in white and grey.
The current market for PVC is mainly white and blue.
From the visual aspect of aesthetic consideration, indoor pipeline should be used PPR pipeline or PVC pipeline.
Six, summarized
Outdoor water supply pipe network using PE pipe, indoor water supply pipe and hot water pipe network using PPR pipe, indoor cold water can be PVC pipe.
