(1) high pressure pipeline
high-pressure pipelines used in oil fields mainly include water injection pipes and oil well pipes. the pipe diameters are small, mostly in the range of dn50-200mm, and the pressure is high, generally between 5-30mpa. for frp, the conditions are relatively high. the performance of domestic glass fiber products is difficult to meet the requirements, and the glass fibers required for the production of such pipes need to be imported from abroad. at present, only the sino-foreign joint venture harbin smith frp products co., ltd. produces such pipelines in china, and has been used in oil fields since 1994. it has successively provided several pipelines for daqing oilfield, jilin oilfield, shengli oilfield, changqing oilfield, liaohe oilfield, etc. ten kilometers of high-pressure fiberglass pipes.
(2) medium and low pressure frp pipes
among the large number of pipelines used in oilfield production, 80% of the pipelines are used to transport oil with high water cut, mixed oil and gas and oilfield produced water. due to the harsh conditions of the oilfield sewage medium, such as the sewage produced in shengli oilfield, its salinity can reach 5.7×104 mg/l, the chlorine content can reach 3×104 mg/l, and there are dissolved oxygen, co2, sulfide, etc. corrosive substances and sulfate-reducing bacteria, therefore, the corrosion of metal pipes is quite serious. when the steel pipe is selected, the perforation will start as soon as 3 months after it is put into production , and it is common to be scrapped within one year. therefore, in 1983, shengli oilfield began to try to use frp pipes with good corrosion resistance as a substitute for steel pipes. in the late 1980s and early 1990s, fiber-wrapped frp pipes were mass-produced in my country, and were soon widely welcomed by oilfields. several large oil fields in china, such as shengli oilfield, liaohe oilfield, zhongyuan oilfield, daqing oilfield, karamay oilfield, jianghan oilfield, etc., have adopted a large number of medium and low pressure winding frp pipes. oilfields, golmud oilfield in qinghai, etc. also use medium and low pressure winding frp pipes to varying degrees. in 1990, only 20km was used in qinghai’s weasel oilfield, and during the period from 1991 to 1992, shengli oilfield used nearly 30km in ground application engineering . therefore, in the past few years, the oilfield has become a glass fiber reinforced plastics industry. a very important application market for pipes. the medium and low pressure glass fiber reinforced plastic pipelines currently used in the oil field are nearly 1,000 kilometers long, and the diameters of the selected pipes are mostly between dn50 and 700mm.
in order to ensure that the wound frp pipeline can better serve the oil field, the oilfield system, together with frp manufacturers and relevant design and scientific research institutes, hold the "frp pipeline application technology promotion conference in oil fields" every two years. starting from the actual situation of the oil field, the company has compiled the technical specification of "low pressure fiberglass line pipe" with reference to api spec 15lr "specification for low pressure fiberglass line pipe" of the american petroleum industry association's fiberglass pipe standard to further standardize and promote the application of winding fiberglass pipes in my country's oilfields. application.
2. chemical industry
in my country, frp pipes were firstly applied in the chemical industry in the 1960s, but at that time, frp pipes were mainly based on tape winding and hand lay-up, with poor anti-seepage performance, so they were not widely promoted in the chemical industry. in 1988, harbin frp research institute and other units successfully processed and produced frp pipes of dn 800mm for conveying salt brine for qinghai golmud salt lake, which played a pioneering and demonstration role for the large-scale application of frp pipes in the chemical industry. since the 1990s, frp pipes have been widely used in the chemical industry. although there have been problems when using frp pipes in a few occasions, the general condition is good. so far, it has been widely recognized in the chemical industry, and many domestic chemical companies or projects have chosen a large number of frp pipes, such as: china wuhuan chemical company, yueyang chemical plant, shanghai petrochemical polyester plant, jinhua chemical group, suzhou chemical group , hubei chemical plant, qingdao shanqing chemical co., ltd., qinghai golmud potash fertilizer plant and other units and hubei huangmailing phosphate fertilizer project, dayukou mineral fertilizer project, chongqing titanium dioxide project, tongling jinlong project and other large projects. the selection of frp pipes in the chemical industry is on the rise. according to the forecast, by 2000, about 30,000 t/a glass fiber reinforced plastics will be used in the chemical industry, and a large part of them will be pipes. the growth rate is higher than other fields, and the application prospect is broad.
at present, most of the frp pipes used in the chemical industry in my country are used as process pipelines and long-distance transportation pipelines. the diameter of frp pipes used in the chemical industry is generally small, mostly below dn800mm, the pressure ranges from normal pressure to 4.0mpa, and the temperature: -40 ~ 100℃. due to the large number of chemical manufacturers, the media conditions involved include various aspects such as acid, alkali, salt, solvent, and acid-base alternation.
three, water supply and drainage
in 1985, a water pipeline was laid between shenzhen and hong kong. the hong kong side used glass fiberglass pipes purchased from the united kingdom, with diameters of dn2200mm and dn1700mm, and a total length of 50km. it is the first time to use frp pipes. in recent years, food-grade resins have been mass-produced in my country and the quality is stable, which has solved the hygienic requirements when frp pipes are used for water supply. coupled with the appearance of frp sanding pipes, the production cost of pipes has been reduced. therefore, the use of frp pipes in the field of water supply and drainage is on the rise, and the market competition is fierce. according to reports: in 1994, the 9km-long daqing west water source to the hongwei chemical industry zone used the dn800mm water pipeline; in 1995, the 5km-long zigong water supply project and the beijing municipal engineering project were about 70km long of dn900mm, dn700mm, dn600mm pipelines; in 1996, yongji, jilin province 17km long dn300mm, dn400mm, dn600mm water supply pipeline, shangzhi water supply pipeline 14km dn500mm long, jilin nong'an 5.1km dn500mm water supply pipeline, panjin ethylene company 30km long processing water pipeline, and other main water pipelines such as dn600mm in hangzhou urban area are all made of frp . in addition, a drinking water pipeline with a length of about 10km and dn700mm in chongyang, hubei is being installed, and a fiberglass drainage pipeline with a length of about 15km and a dn1200mm in taicang, jiangsu is also under planning and construction.
most of the frp pipes used in the water supply field are of medium and small diameters, and most of the frp pipes used in the drainage field are of large and medium diameters. the pressure during water supply and drainage is generally low, so they have good corrosion resistance, light weight, and easy installation. convenient, excellent hydraulic performance, but generally unable to withstand high pressure (sand) frp pipes are especially suitable for this field. with the development of my country's economy and the development of municipal construction, the application of frp pipes in this field will be more and more.
4. power station
the application of frp pipes in power plants began in the middle and late 1980s. at that time, the yangbajing geothermal power station in tibet selected the frp pipes produced in japan for circulating geothermal water; the haikou power plant selected 24m long, dn1600mm frp pipes circulate generator cooling water. after that, in 1990 and 1992, the yangbajing geothermal power station in tibet again selected nearly 5 million yuan of glass fiber reinforced plastic pipes in the second and third phases of expansion. the pipe diameters range from dn500 to dn900mm. these pipes are in good condition so far. in 1996, qinshan nuclear power plant selected dn 1800mm and dn2800mm glass fiber reinforced plastic pipes in the second phase of construction, with a total contract price of about 10 million yuan; in 1997, shenzhen west hydropower plant selected seven specifications of glass fiber reinforced plastic with nearly 2 million yuan from dn100 to 1200mm. pipes, in addition, zhanjiang power plant, baoji no. 2 power plant and other units also selected frp pipes.
the frp pipes used in power stations (plants) are generally used as circulating water pipes, chemical water pipes, supply water pipes, rainwater pipes and seawater desulfurization pipes. its use is currently in the ascendant stage. the number is limited, and many advantages of frp pipes have not been recognized and accepted by the power industry. therefore, in the entire application of frp pipes, this part of the market has not yet occupied a large share, but there is a great market potential to be tapped.
5. extraction of corrosive gas chimney
because the glass fiber reinforced plastic pipe is integrally formed, it can withstand the negative pressure generated by the extraction when it is used as a chimney to extract corrosive gas, and will not produce delamination; in addition, the glass fiber reinforced plastic pipe is light in weight, easy to hoist, and through design, it can resist different wind pressure and shock load, and the anti-aging performance is also very good. therefore, frp pipe is an ideal pipe for chimney. in 1991, the 47m high, dn2800mm and dn3200mm chimneys used in the 404 titanium dioxide project in gansu; in 1994, the 100m high dn2200mm chimneys used in the huangmailing ammonium phosphate project; in 1995, the dn3000mm chimneys to be used in the shenzhou ammonium phosphate plant in hebei and the qinshan nuclear power plant were both. made for fiberglass pipes. frp pipes used as chimneys to extract corrosive gases is one of the markets with great potential.
in addition to the above five application fields, frp pipes are also used to varying degrees in papermaking, tanning, food, ventilation and other fields in my country, and the scope of use is becoming more and more extensive. however, the number of frp pipes used in all these fields is still very limited. therefore, the application of frp pipes in these fields still needs to be further developed.