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Present situation and development trend of production and application of PVC pipe

Date:2017-09-01 10:09:16 Browse times:1036

Hard PVC pipe, pipe fittings in many PVC products, in our country showed a rapid growth trend, but also the largest variety of plastic pipes in the consumption of varieties. PVC pipes in China after years of promotion, especially the national related policy support, production and application of PVC pipe has achieved great development, PVC pipe plastic pipe production has accounted for more than 50% of the total production, widely used in many industries, industrial construction, agriculture etc..

Development of PVC pipe

1.1 PVC pipe strengths

In the production of general resins, the consumption of ethylene is lowest and the production cost is the lowest with PVC resin. Domestic production of PVC per ton of ethylene consumption of 0.5314 tons, while the per ton polyethylene consumption of 1.042 tons of ethylene, domestic PVC per ton of ethylene resin consumption less than polyethylene consumption of about 50%. Chlorine, the raw material used in the production of PVC, is an important way to balance the production of chlorine from caustic soda. Caustic soda is an essential and important raw material for the national economy. In addition, from the point of view of plastic products, PVC and various additives compatibility is good, in the production of pipe can be added a large number of low filler, so that production costs greatly reduced.

Compared with PVC pipe and metal pipe production, and production of PVC per cubic meter per cubic meter of steel and aluminum, steel consumption is 316KJ/m3, the energy consumption of aluminum is 619KJ/m3, the energy consumption of PVC is 70KJ/m3, the steel consumption is 4.5 times that of PVC, the energy consumption of aluminum is 8.8 times PVC. And the processing energy consumption of producing PVC pipe is only 1/3 of that of the same caliber metal pipe. At the same time, due to the smooth wall of the PVC pipe, no corrosion, water delivery efficiency, used for infusion can save about 20% power.

PVC pipe has good mechanical properties, and has excellent corrosion resistance, in the process of using light weight, convenient installation, no maintenance, and the use of steel for sewer utilities, in use because of easy corrosion, often must be coated with paint, high maintenance costs. General construction and public works with metal pipes need to be replaced for about 20 years, and the role of good processing PVC pipeline, the service life of up to 50 years. Therefore, PVC pipe is a kind of good plastic product with low cost, high strength and good corrosion resistance.

Generally speaking, in the sewage, waste water and ventilation pipe, PVC pipe than using iron pipe installation and labor cost savings of about 16-37%; as a conduit than cost saving 30-33% use metal wire casing; and the effect of chlorinated polyvinyl chloride (PVC) pipe in hot and cold water, than to use the same size of the copper tube to save cost for 23-44%. Therefore, due to the advantages of PVC pipe, all countries are actively developing and promoting PVC pipe.

Production and consumption of 1.2 PVC pipe

Since 80s, China has introduced different types of PVC pipe extrusion production line 1000, emerged as Dalian Shide, Zhejiang Yong high, Shanghai Tangchen large pipe manufacturer. At present, China's UPVC (hard PVC) pipes and fittings production factory has more than 600, more than the total production capacity of 1 million 100 thousand tons / year, manufacturers in the production scale of 10 thousand tons / year of above more than 30, the scale in the 0.5-1 million tons / year of more than 60 manufacturers, UPVC pipes and fittings production equipment basically achieved domestically.

In China, PVC tube is PE pipe and PP tube development early, many varieties, excellent performance, wide use, occupies an important position in the market. By the end of 1999, there were about 2000 plastic pipe production lines in China, of which about 15% were imported. In 1999, the production capacity of various plastic pipes in China exceeded 1 million 650 thousand tons / year, and the actual output was about 1 million tons, of which UPVC pipes accounted for more than 50%.

Over the years, in the world's PVC market applications, the building materials market is the largest, and the fastest rate of increase. In recent years, the United States building materials products accounted for 60% of its total products, Western Europe was 62%, Japan's 50%, China's proportion is less than 30%, rising space is great. In building materials products, the main pipe and profile, including the construction of water pipes, irrigation pipes, gas pipelines, crude oil pipelines.

The production and application of UPVC pipes in China began to develop rapidly during the period of "95", mainly due to the strong support from the government and the society's understanding of UPVC pipes.

At present, the application of plastic pipes in our country is not only in quantity, but also in varieties and specifications have been greatly developed. Such as UPVC pipe in some cities, building drainage applications have reached more than 90%, and most of the UPVC pipe enterprises in recent years, very good results.

During the "fifteen" period, the plastic pipes were mainly promoted by UPVC and PE plastic pipes, and other new plastic pipes were developed vigorously. By 2005, the national construction, renovation and expansion project, building drainage pipeline with 50% plastic pipe, plastic pipe by 20% city drainage pipeline, building water supply, water supply and heating pipes 60% using plastic pipe, city water supply pipe (Dn400) with 50% plastic pipe, rural water supply pipeline 60% using plastic pipe, city gas pipeline (low pressure pipe) with 50% plastic pipes, building wire protecting pipe with plastic pipe 80%. Plastic pipes are expected to be around 2 million tons in 2005, most of which are PVC pipes.

In developed countries, PVC tube consumption generally accounts for 70-80% of plastic pipe market, while China's PVC pipe accounts for only about 50% of the total plastic pipes, and the development potential of PVC pipes in our country is very huge. Developed countries PVC various pipe material consumption ratio is: water supply pipe accounted for 33%, the sewer pipe accounted for 22.3%, sewage pipes accounted for 15.7%, irrigation pipes accounted for 5.2%, gas pipes accounted for 0.8%, and other pipes accounted for 22.7%. Among them, the consumption of pipes and pipes is about 1:8.

In the construction market, the use of PVC pipe has two kinds: one is the pressure pipe, and the other is the non pressure pipe. Cast iron pipes used in the past and 

As a pressure resistant building material, copper tube is not only seriously corroded, but also needs regular maintenance and replacement. Foreign construction is now widely used pressure water pipes, hot water supply pipes, most of the use of PVC pipe. Small caliber PVC tube (UPVC tube, CPVC tube) has the advantages of low cost, corrosion resistance, no need of regular maintenance and replacement. The large caliber PVC pressure pipe (100-900mm in diameter) replaces cast iron pipe and strengthens small mud pipe. The water supply system has good fluidity, corrosion resistance and low weight. Electricity saving and good water quality. The PVC core layer foaming non pressure pipe is used as the indoor sewer pipe and the rainwater system pipe, and the utility model can solve the noise problem of the indoor water pipe well. The utility model adopts a non pressure PVC pipe, which has the advantages of corrosion resistance, no hydrogen sulfide erosion, long service life, light weight, low installation cost, easy connection and sealing, and is not easy to break. In addition, the construction of pipe string and underground cable protection pipe is another market for PVC pipe products. At present, the domestic varieties are straight expansion tube, double wall tube and single wall corrugated pipe.

Agricultural pipe is another broad field of PVC application. China is a country that lack water resources, at present, China has the most farmland irrigation canal, water waste is very serious. Because of lack of water, a large amount of cultivated land can not get very good irrigation, and the yield of crops is low. Irrigation with PVC pipes can save water by about 50%. The use of PVC fixed or semi fixed irrigation system farming, not only saves water, but also can improve production, equipment is not corrosive, etc., greatly saving the cost of irrigation and spraying facilities. At present, there is no one county in China fully managed irrigation, the vast majority of areas in the country are still lack of basic understanding of irrigation management. Therefore, the propaganda and promotion of PVC irrigation in rural areas are greatly increased, and its potential is enormous.

1.3 some commonly used PVC pipes in China

UPVC tube: UPVC pipe is the largest application of the construction industry. At present, it is popularized and applied in the water pipeline system and the residential water pipe in all provinces and cities of China, and is mainly used as drainage pipe, rainwater pipe and threading pipe in the construction industry. UPV tube has the advantages of chemical resistance, self extinguishing and flame retardancy, good chemical resistance, smooth inner wall and good electrical performance, but the UPVC tube has low toughness, high coefficient of linear expansion and narrow temperature range of use. The development of UPVC pipe production efficiency obviously, and the use of UPVC pipe cast iron pipe production and use of such 55-68%, UPVC water supply pipe than galvanized pipe such 62-75%, and the same size per unit length of the price of only 1/2 galvanized pipe, galvanized pipe installation costs than low 70%, using 1 tons of UPVC water supply pipe can replace 12 tons of cast iron pipe, application 1 tons of UPVC corrugated pipe can save 25 tons of steel.

The core layer foaming pipe: the core layer foaming pipe is the three layer co extrusion production process of the two layer and the UPVC tube, the middle is a new type of tubing with relative density of 0.7-0.9 low foam layer, the circumferential rigidity is 8 times that of ordinary UPVC tube, and a change in temperature scale has good stability, heat insulation well, especially the foam core layer can make out the noise propagation, more suitable for the high-rise building drainage system.

Compared with the solid tube, the foamed core tube can save more than 25% of the raw material, and the internal wall compression capacity is greatly improved. In the wall with a foam core muffler several convex spiral tube water continuously along the inner wall of the pipe free spiral flow in the central drainage pipe to form a gas column, the tube pressure is reduced by 10%, the general capacity increased by 10 times, the drainage amount increases 6 times, lower noise than ordinary 30-40db UPVC drainage pipe.

PVC radial reinforced pipe: this kind of pipe is made of special mould and forming follow-up device. It is a heavy, big caliber and super strong ring corrugated pipe. The utility model is characterized in that the outer wall of the pipe is provided with a radial reinforcing rib, and the utility model can greatly improve the ring rigidity and the compressive strength of the pipe, and is especially suitable for draining water in the municipal engineering.

Double wall corrugated pipe: double wall corrugated pipe is extruded at the same time two concentric tubes, and then bellows outside the tube welded on the inner wall of the smooth copper tube made of. With a smooth inner wall and corrugated outer wall, light and high strength, than ordinary UPVC pipe can save 40-60% of raw materials, mainly used as communication cables, protective pipes, building exhaust pipes and agricultural drainage pipes.

PVC through time reinforced tube: made by extrusion of two layers of plastics inside and outside, with synthetic fiber in it, flexible and flexible. PVC transparent tube has better acid resistance, alkali resistance, oil resistance, aging resistance, can replace rubber pipes, and the price is cheap. Widely used in nitrogen, oxygen, carbon monoxide and other gases and water, dilute alkali, oil and other liquid transport, but also can be used as water heaters, sprayers, gas stoves and other catheter.

CPVC pipe: CPVC pipe is a kind of heat resistant plastic pipe made of chlorinated polyvinyl chloride with chlorine content as high as 66% or more. The heat resistant temperature of CPVC pipe is higher than that of pipe, and the dimension stability is improved, and the coefficient of linear expansion is lower than that of UPVC pipe. CPVC tubes are excellent in heat resistance, aging resistance, chemical resistance, and are not deformed in boiling water. They can be used in hot water, corrosion resistant liquids and gases. Domestic Li Li Co., Ltd. produces CPVC pipe.