The thermal conductivity of polyurethane is: λ=0.013—0.03kcal/m·h·oC, which is much lower than other commonly used pipe insulation materials, and the thermal insulation effect is improved by 4~9 times. Further, its water absorption rate is very low, about 0.2 kg/m2. The reason for the low water absorption rate is that the closed cell ratio of the polyurethane foam is as high as about 92%. The low thermal conductivity and low water absorption, plus the high-density polyethylene or FRP protective shell with good insulation and outer waterproofing, change the condition of the traditional ditch laying heating pipe “wet cotton quilting”, greatly reducing the heating pipe. The overall heat loss, heat network heat loss is 2%, far less than the international standard of 10%. 2, low heat loss, energy conservation According to the calculation of the relevant departments, under normal circumstances, polyurethane insulation steel pipe can reduce the project cost of 25% (using FRP as a protective layer) and 10% (using high-density polyethylene as a protective layer). 1. Reducing the advantages of engineering cost polyurethane insulation pipe:
The outer anti-corrosion coating of the oil pipeline. In December of the same year, the China Petroleum Infrastructure Bureau, the Pipeline Bureau, the Sichuan Petroleum Design Institute, the Northwest Pipeline and the Command Experts jointly organized a group to go to the United States, Italy, and many pipeline coating systems. China National Petroleum Corporation decided to introduce 3PE coating operation and coating technology in the summer of 1994 for the Shaanxi-Beijing gas pipeline and library to be started soon.
Production enterprises do not participate in disorderly competition, do not participate in vicious competition at below cost; continue to promote the lead-free work of PVC-U oil pipelines; strengthen the factory inspection and production of inferior products for the application field, and guide the regulation of market behavior. It is necessary to improve the technical level, quality level, product grade and improve the competitiveness compared with other traditional pipelines.
The service of Hunan LSAW Seamless Steel Tube Plant is supreme. On December 9th, when listening to the general situation report of the mass line education practice activities of the Hebei Provincial Party Committee, once again stressed that it is necessary to make great efforts to reduce the production capacity of seamless steel tubes and control pollution. For the medium and long term, the seamless steel pipe production capacity will return to a reasonable range, and the contradiction between supply and demand will be eased, which is conducive to the stability of the steel market. Seamless steel pipe theory weight table: profiteering has gone far, the current situation is growing in the crack.
Hunan LSAW seamless steel pipe factory service first
Large-diameter steel sleeve steel insulation pipe is quoted, so it is suitable for transportation with strong corrosive oil or under high temperature conditions. Seamless steel pipes are divided into hot rolling and cold drawing. Since the cold drawing process causes the material to harden, the pipes used in the oil pipeline are mainly carbon steel pipes, which can be divided into seamless steel pipes and welded steel pipes according to the manufacturing process. The seamless steel pipe has the characteristics of high strength, large specifications, etc. The development of the pipe and the applicable materials and specifications of the dynamic technology, the related technology has been widely used in the pipeline transportation of oil products. 
Zhejiang water supply black jacket insulation pipe manufacturers, in the early 1980s, 3PE anti-corrosion steel pipe was first widely used in Europe, praised by users, is the use of a lot of pipeline coating system. In the summer of 1994, China National Petroleum Corporation decided to introduce 3PE coating operation and coating technology for the external anti-corrosion coating of the Shaanxi-Beijing gas pipeline and the Kuqin oil pipeline that will be started soon. In December of the same year, experts from the China Petroleum Infrastructure Bureau, the Pipeline Bureau, the Sichuan Petroleum Design Institute, and the Northwest Pipeline Command team jointly went to the United States, Italy, Turkey and other countries to inspect the 3PE coating line. In May 1995, Liaohe Oil Construction Company was responsible for the tendering and introduction of China's 3PE coating line from Canada Root Labor Company. It was put into normal production at the beginning of 1996. In 1996, the Suzhou anti-corrosion plant jointly established by Soksam Company of Italy and Harbin Plastics Sixth Factory was put into normal production in May. The 3PE coating line imported from the Netherlands by the Northwest Pipeline Command and the Hong Kong Merchants Joint Venture was completed and put into operation in 1996 at Baoji Yadong Anticorrosion Co., Ltd. So far, 3PE anticorrosion has received attention and application in China. Since the construction of the Suininglan pipeline, through the bidding, and the localization of 3PE anti-corrosion materials, the prefabrication price of 3PE anti-corrosion has dropped drastically. Since then, the era of extensive application of 3PE anti-corrosion has been started. So far, 20,000KM buried steel pipe anti-corrosion has been treated with 3PE anti-corrosion coating. Floor. At present, there are dozens of 3PE coating lines with the ability to process 3PE coating of Φ25-2800mm steel pipe. Development status