青岛大仓管道

　　Steel pipe anticorrosive & heat-insulated foam jacket molding technology is the new technology popularized in domestic oil fields in 1980s after original Ministry of Petroleum Basic Construction Bureau organized experts to visit Canada for inspection and review. On base of foreign “two-step” molding technics, in 1983, Shengli Oil field Process Engineering Research Institute firstly extended “one-step” molding technology, that is, one-time molding of steel pipe foam anticorrosion and heat-insulation technology and outside heat-insulated jacket layer, which is called “one-step” operation. The success of this process engineering not only enhances operating efficiency but also greatly saves material, reduces cost and makes construction convenient. Soon, this technology was popularized in oil fields all over the country and acquired Shandong Province Ten Excellent Scientific & Technological achievements. Furthermore, it acquired national invention patent in 1985 and till now, no “one-step” technology come into the world in our country.
　　The key of influencing popularizing “one-step” molding technics in foreign countries is that, color of foam material adopted domestically is yellow and jacket layer is yellow polyethylene material, which is commonly called yellow jacket but generally used in foreign countries is black jacket. However, there are series of technical problems of our “one-step” operating line haven't solved, such as splicing strength, protective layer adopting black jacket, etc.
　　In recent two years, Qingdao Dacang Pipe Anti-corrosive & Heat-insulated Equipment Co., Ltd, aiming at existing problems of “one-step” method, organizes experts to tackle key problems to acquire six key technical breakthroughs and own essential and technical breakthrough on past general “one-step” operating line, which is called new “one-step” operating line by us.
I Six technical breakthroughs
1. Breakthrough of becoming into black (jacket) from yellow (jacket)
　　After paying a visit to “one-step” production line, the Asia sales manager of Germany Bayer Corporation ever evaluated that “this process engineering is very advanced but same kind of product in Europe the jacket color is black and jacket and foam is spliced. These two points are quite important and they determine ageing resistance of product and stability of layer structure.” The foreign research test result proves that ageing resistance of black jacket is enhanced by 20 times than yellow jacket. Therefore, it's certainly that black is not only the color problem but also quality problem. Black jacket owns excellent performance on ultraviolet and ageing resistance which can't be compared. Compared to yellow jacket, yellow jacket will chap once under sunshine but black jacket won't chap.
2. Foaming location visibility technology breakthrough
　　Key technology of adopting black jacket is solving visibility of foaming location to observe foaming quality and blow hole which may forms when foaming. Otherwise, black jacket will become an empty talk. Our company successfully developed black foam jacket “one-step” technics tester and this instrument can observe foaming location directly through black jacket layer from television screen and make foam jacket pipe act as a pioneer in manufacturing application of “one-step” method.
3. Breakthrough of splicing technology of foam and jacket
　　Carry through electropolarized treatment on inside wall of protective layer black jacket to make nonpolarized polyethylene material polarized and then spliced with polarized polyurethane foam plastic. Accordingly they will form splicing layer of foam and jacket and make they firmly splice together.
4. Adopt pitch polyurethane foam plastic as heat-insulated material
　　Make heat-insulation and anti-corrosion 2 in 1 and form black jacket and pulp, realizing “black and black” optimal combination. Owing to successfully developed foaming location visibility technology, adopting pitch polyurethane foam material “pipe-in-pipe” technology become possible.
　　 Pitch polyurethane foam plastic is made through adding 30% to 40% pitch into common polyurethane foam plastic to make it modify into neutral material from acid material. At the same time, the pitch polyurethane foam plastic is enhanced on ageing and ultraviolet resistance and it makes buried pipe line effectively resist insect and mouse bites. It undoubtedly increases service life of anticorrosion and heat insulation of pipe and it generally can reach 20 years.
Comparison between Pitch polyurethane foam plastic and common polyurethane foam plastic

Sort Item	Polyurethane hard foam plastic	Pitch polyurethane foam plastic
Water permeability	Water permeability is not as good as pitch polyurethane foam plastic	Own water permeability
Ageing resistance	Don't resist atmospheric weathering and ageing resistance is poor.	With excellent splicing property on basis material and ageing resistance, it can resist atmospheric weathering action.
Anti-corrosive property	Flame-retardant hard foam easily gives off acid substance and corrodes steel material and pipes.	Hard foam is neutral and owns anti-corrosion on steel pipe and pipe materials so that bottom layer anticorrosion can be cancelled.
Catalyst dosage	Many kinds of catalyst variety are required and dosage is large as well.	Pitch contains amido group, imdo group and other active hydrogenated compound so that owns catalytic action.

After using pitch polyurethane foam plastic, steel pipe can do without anti-corrosive layer and anticorrosion technics is simplified and cost is reduced by 10% as well.
5. Breakthrough of rectifying organization is converted into hydraulic pressure drive from electric drive
　　The former “one-step” rectifying machine is rectifying organization which is driven by electric motor and easily make motor burn out after touching water. After converted into hydraulic-pressure drive, it takes hydraulic-pressure station as drive and does automatic rectification on non-central foam jacket layer through four hydraulic-pressure oil cylinders.
6. Breakthrough of splicing strength of anti-corrosive and heat-insulated layer
　　It makes it don't displace and leads to possibility of canceling waterproof cap accordingly to reduce cost greatly and innovate technics as well.
II Excellent performance-price ratio
　　New “one-step” operating line owns advantages of single machine combination and can be combined at will according to technic requirement. Furthermore, its cost and price are both not higher than “one-step” operating line.
III Excellent economic flexibility
　　1. After adopting new “one-step” operating line, owing to superiority of machine and excellent splicing property of jacket and heat-insulated layer, the pipe tie-in doesn't damage easily and waterproof cap in technics can be cancelled to reduce cost of anticorrosion and heat-insulation by 20% to 30% greatly.
　　 2. Adopting pitch polyurethane foam plastic can reduce cost by 5% to 10%
　　 3. Anticorrosion and heat-insulation service life is prolonged and improved by 10 to 20 times than former “one-step” method.
　　 4. Sunlight resistance and anti-detonating property of pipeline is strengthened.
IV Application Condition & Prospect
　　Application in 400km pipe of Qinghai Oil Field further proves that the new “one-step” technics is really feasible and the operation of equipment is simple and product quality is excellent. Liaohe Oil Field and many other oil fields have ordered this kind of product and technics.