What are the ways of pipeline anticorrosion ?
1, pipeline external anti-corrosion design petroleum asphalt
This is a relatively old pipeline anticorrosion method, mainly used in dry areas. But now are the use of epoxy coal asphalt to replace petroleum asphalt to do anti-corrosion, not only good anti-corrosion effect can be excellent, the price is more affordable.
2, pipe wall coating anticorrosive paint
This way is to use paint on the outer wall of the pipeline, but to maintain uniform and dense, the pipeline and a variety of corrosive media to separate, which is a more commonly used pipeline anticorrosion method. For example, ProteKO-COAT 1114 environmentally friendly outer coating is a high-quality outer coating product that has both excellent impact resistance and good surface penetration. The PROTEKO-COAT 1114 Environmentally-friendly outer coating forms a clean and robust film that effectively resizes cracks, peeling and scaling that may occur under various working conditions. Proteko-coat 1114 is an environmentally friendly coating for tubing, casing, pipe, drill pipe, coiled tubing, riser, steel tank, structural steel and drilling rig.
- Coating the inner wall of the pipeline with anti-corrosion coating
The anticorrosive paint is applied to the inner wall of the tube to ensure that it is tightly adhered to the inner wall of the pipe, but before applying, the inside must be cleaned up first, and there can be no impurities such as water and oil. For example, PROTEKO-COAT 710 degradable drill pipe inner coating is a degradable coating for the oil and gas industry specifically designed to prevent corrosion on the inner surface of drill pipe during storage. Proteko-coat 710 degradable drill pipe inner coating is a petroleum-free hydrocarbon based product and contains only trace amounts of hydrocarbons. Proteko-coat 710 degradable drill pipe inner coating is an environmentally friendly coating that does not emit a harsh smell similar to fish oil like some conventional coatings. The PROTEKO-COAT 710 degradable drill pipe inner coating is composed of an anti-rust agent to prevent possible corrosion of the drill pipe inner surface. Proteko-coat 710 is a biodegradable internal coating for use on drill pipe, drill collar and other related drilling equipment.
What is the role of pipeline anticorrosion
After the pipeline is treated with anti-corrosion, it can effectively prevent it from being corroded by soil or air. Now most of the pipelines are used to transport gasoline and other substances, and these substances contain a lot of corrosion, so in order to avoid pipeline corrosion, you must do a good job of anti-corrosion work, which can also effectively reduce environmental pollution. In addition, pipeline anticorrosion can also avoid the phenomenon of oil leakage to a certain extent, and play a role in safety protection.
Precautions for pipeline anticorrosion construction
When carrying out pipeline anticorrosive engineering, the first thing to pay attention to is the ambient temperature, which must be constructed in an environment above 5 ° C and humidity below 80%. All materials must be deployed in accordance with the prescribed proportion, and the lap length of the dry cloth head part must be controlled between 10cm and 150cm.
Steel piping definition
Steel pipe: steel pipe, pipe fittings made of carbon steel, stainless steel, alloy steel, composite steel and other steel materials, it is commonly known as steel pipe, and steel pipe has the same place, there are also different processes.
Which steel grades of pipes need corrosion protection?
Generally, the corrosion resistance of steel pipes is limited, which is mainly reflected in carbon steel pipes and pipe fittings, composite steel, alloy steel, stainless steel is relatively better. Carbon steel refers to iron carbon alloy with carbon content of 0.0218%~2.11%. Also known as carbon steel. Generally also contains a small amount of silicon, manganese, sulfur, phosphorus. Generally, the higher the carbon content of carbon steel, the greater the hardness, the higher the strength, but the lower the plasticity. Including: high and low carbon steel, cast carbon steel, ductile iron, malleable steel and so on. Generally need anticorrosive carbon steel grades are: 10#, 20#, 45#, 16 manganese, 16Mn, Q345ABCDE, Q235ABCDE, Q245R, Q345R, Q195, Q215, Q255, Q335, A3, A105, 16MnR, and other grades.
What kinds of steel pipes can be divided into?
Steel pipe: seamless steel pipe, straight seam welded pipe, spiral steel pipe, hot expanded steel pipe, cold drawn steel pipe, hot rolled seamless pipe, square pipe, oval pipe, shaped steel pipe, concrete pump pipe, large diameter thick wall coil pipe, T-welded steel pipe, etc.
Pipe fittings: elbow, flange blind plate, three-way, four-way, size head, reducing pipe, sealing head, pipe cap, big bend, etc.
Valve: electric valve, manual valve, cast steel valve, cast iron valve, welding valve, gate valve, butterfly valve, etc
Miscellaneous: waterproof sleeve, ripple compensator, expansion joint, rain cap, rain bucket, insulation joint, damper, support hanger, cowl, flame arrester, sight mirror, bolt gasket, explosion door, flare, etc
Trench pipe fittings: fire pipe fittings, malleable steel pipe fittings, ductile iron pipe, etc
What are the types of steel pipeline anticorrosion?
Steel pipeline anticorrosion according to the form of the pipeline can be divided into: inner wall anticorrosion and outer wall anticorrosion, the overall anticorrosion three.
2PE/3PE anti-corrosion: only applicable to the outer wall of steel pipe and pipe fittings, polyethylene particles are sprayed on the outer wall of the pipe after hot melting. It can be divided into: enhanced grade and ordinary grade. 3PE anticorrosive pipeline with light weight, high strength, insulation, sound insulation, flame retardant, cold resistance, anticorrosion, no water absorption, construction and other superior characteristics, has become the construction, transportation, kerosene, chemical, electric power, cold storage and other industries all insulation anticorrosion, waterproof plugging, sealing and other indispensable information. 3PE anticorrosive steel pipe is used for the anticorrosion and cooling engineering of various pipes in the room and surface, heating pipes, local air conditioning pipes, chemical industry pipes, etc. 3PE pipeline anticorrosion from inside to outside is divided into three layers of pipeline anticorrosion layer 1: task steel pipe layer in accordance with the attempt and customer request 1 seamless pipe (GB eight 163-87) spiral welded pipe (GB9711-88; SY/T503 8-92) and straight seam welded pipe (GB3092-93). After the rust removal process of the previous generation, the rust removal of the steel pipe can reach the Sa2 level in the GB 8923-19 88 specification, and the external precision can reach R=12.5 microns in the GB6060.5-88 specification. The second layer of pipeline anticorrosion: The 3PE anticorrosion layer is formed by injecting rigid 3PE foam liquid into the cavity formed between the outer protective layer of the steel pipe with a low pressure foaming machine. It is commonly known as the “tube in tube foaming process”. Its infection 1 is waterproof, 2 is anti-corrosion, and the third is to support the weight of the heat supply network. When the temperature of the conveying medium is: -50 to 120 degrees Celsius, the hard polyurethane foam is used as the anti-corrosion layer. 3PE anticorrosive steel pipe is therefore foamed by chemical reaction based on polyether polyol composition and polyphenyl isocyanate. The third layer of pipeline anti-corrosion: high-density polyethylene precious layer is prefabricated into a color (yellow) plastic pipe with a fixed wall thickness, and its infection is 1 that the precious 3PE anti-corrosion layer is not crushed by stagnant hard objects, and 2 that is anti-corrosion and waterproof. The use of 3PE anti-corrosion steel pipes should be used to transport various media in the range of -50 to 150 anti-corrosion and cold protection projects. It is widely used in rural heating, heating room, cold storage, coal mine, kerosene port, chemical industry and other industries of anti-corrosion and cooling engineering.
2PP/3PP anticorrosion: It is the way of heating and spraying anticorrosion of polypropylene particles.
FBE epoxy powder anticorrosion: is the internal epoxy powder electrostatic spraying, good performance, high price.
TPEP anti-corrosion: is the internal epoxy resin powder electrostatic spraying, external 3PE anti-corrosion, good performance
TPEP anticorrosion: the general term for internal epoxy external 3PE, which is suitable for steel pipes and pipe fittings, with good performance and high price.
IPN8710 anticorrosion: mainly applied to the inner wall of drinking water supply pipeline, drinking water non-toxic anticorrosion. IPN8710 Drinking water anticorrosive steel pipe on tap water, drinking water. Modification of epoxy resin. Epoxy resin is so far, a large number of applications in the world, a wide range of very important resin, but the great limitations of epoxy resin applied to the inner wall of heavy IPN8710 drinking water pipeline are poor weather resistance, easy to powder, brittle, easy to change color, not suitable for processing into heavy IPN8710 drinking water pipeline inner wall resistant to chemical atmosphere. Modification of stem oleic acid resin. Stem oleic acid resin is a synthetic resin with high decorative and excellent protective properties. Its main advantages are excellent outdoor weather resistance, excellent adhesion, good alkali resistance, excellent light and color preservation, good ultraviolet resistance, moisture prevention, salt spray prevention, mold prevention, heat and chemical corrosion resistance, bright and full color, hard and wear-resistant, water and oil resistance. But there are poor ammonia resistance, oxidation resistance to acid, acetic acid, ethanol is not ideal weakness. Modification of chlorinated rubber. Chlorine-containing rubber refers to rubber polymers containing a large number of chlorine atoms, which have the advantages of flame retardancy, self-extinguishing, enzyme resistance, water resistance, acid resistance, alkali resistance, salt resistance, chemical corrosion resistance, good mechanical strength, construction is not subject to seasonal and climatic conditions, fast drying speed, and can form films at low temperatures. However, there are defects such as thin anticorrosive pipeline coating, high temperature resistance (generally not more than 60), poor permeability resistance, solvent resistance and moisture resistance, and it is difficult to make high solid component weight IPN8710 drinking water pipeline inner wall.
Epoxy ceramic anticorrosion: Epoxy ceramic is composed of epoxy resin and a large number of (weight ratio of more than 50) quartz powder anticorrosion coating. The coating hardness is high, smooth and wear-resistant, but it has certain willfulness. It is a pipeline lining material with high mechanical strength, large bonding force and excellent anti-corrosion properties. Mainly used to transport sewage, water cast iron pipe, steel pipe inner wall anticorrosion, white pottery appearance white, mainly used to transport drinking water, water cast iron pipe, steel pipe inner wall anticorrosion, epoxy ceramic products can also be used for steel storage tanks, concrete ponds, sewage treatment plants, chemical plant equipment inside the anticorrosion.
Galvanized pipe: steel pipe fittings are basically applicable, generally divided into galvanized steel pipe, and after hot dip galvanized treatment.
Plastic coating pipe: plastic coating is suitable for the inner and outer walls of steel pipes, and it is coated after the whole heating, with good performance and high price. The modified heavy anticorrosive epoxy resin powder used in the epoxy composite steel pipe has excellent chemical corrosion resistance, which fundamentally solves many problems such as surface rust corrosion and inner wall scaling after long-term use of similar products, and avoids internal blockage affecting the use of the phenomenon, thus greatly improving the service life of the special fire pipe. Due to the addition of flame retardant materials in the coating material, the temperature resistance of the product has been improved compared with other similar products, and the price is almost the same as that of ordinary galvanized pipes. The product can be selected according to different requirements of users to add flame retardant red polyethylene (PE), crosslinked polyethylene (PE-X), epoxy resin (EP) on the inner and outer walls of the steel pipe. Smooth surface, reduce fluid resistance, increase flow, and no scaling, will not clog the pipe and clog the spray head phenomenon.
Spray pipe: It is suitable for spraying anti-corrosion processing after the overall heating of pipeline parts. Good performance, high price.
Plastic lined rubber lined PTFE pipe: suitable for the inner wall of the pipe, the pipe after heating spray treatment, mostly suitable for small pipe fittings.
Paint pipe: Suitable for small parts of the pipe fittings or pipe fittings of the overall paint anticorrosion, more reliable than painting.
Brush anti-rust paint anticorrosion: suitable for the inner and outer walls of the pipeline, is only the simplest form of anticorrosion, the color can be customized by the customer.
Epoxy coal asphalt paint anticorrosion: generally divided into three oil two cloth, four oil six cloth anticorrosion, suitable for pipeline wall anticorrosion. Oxygen coal asphalt coating according to its use function is divided into epoxy coal asphalt primer and epoxy coal asphalt top paint two categories. Epoxy coal asphalt anti-corrosion coating is composed of two main components of epoxy and coal asphalt, is a (epoxy) B (curing agent) two-component coating, with excellent adhesion, toughness, moisture resistance, water resistance, chemical medium resistance, with the ability to prevent various ions through the paint film, with the same expansion and contraction characteristics with the coated object. The paint film never falls off or cracks. Thickness 0.5 ~ 1.0mm. Epoxy coal bitumen is a cost-effective form of anticorrosion, the engineering test shows that epoxy coal bitumen with cathodic protection. Oil and gas pipelines have been used for 20 years without corrosion. The components are epoxy coal asphalt primer and top paint, which are made of epoxy resin and coal asphalt as the main film forming material, adding various anti-rust pigments, insulating fillers, toughening agents, leveling agents, diluents, anti-settling agents, etc. The B component is modified amine curing agent or curing agent as the main material, adding makeup filler. When the product is sold, A and B components are supplied, mixed proportionally during construction, and used up within the specified time after mixing evenly. According to the solid content, it is divided into two categories: solvent-free (GH 201) and thick slurry (GH 202), and according to the heat resistance temperature when the coating is used, it is divided into temperature resistant type (used within 150 ° C, adding W) and standard type (used within 100 ° C), for users to choose according to the actual requirements of anti-corrosion engineering. The enterprise standard of this product is Q/DH 02-2009 “Liquid epoxy anticorrosive coating”, its technical indicators are the same as China’s oil and gas industry standards SY/T 0447-96 “Buried steel pipeline epoxy coal asphalt anticorrosive coating technical standard” and SY/T 0457-2000 “Steel pipeline liquid epoxy coating internal anticorrosive coating technical standard”. It also meets the requirements of the American Waterworks Association standard AWWA C 210-03 “Internal and external anti-corrosion coating of liquid epoxy coating for steel water pipes”.
Cement mortar lining anti-corrosion: mostly applied to the inner wall of the pipeline, mostly used for the inner wall of the drainage sewage pipeline anti-corrosion. The anticorrosive materials in cement mortar should meet the following requirements: (1) The water supply pipeline should not use admixtures that pollute water quality and hinder human health. (2) Anti-corrosion materials that are corrosive to pipelines and pollute water quality shall not be used in construction. (3) The mortar mixing water should be clean water that has no effect on the strength and durability of cement mortar. The internal anti-corrosion of the buried pipe and the open pipe are hung with galvanized wire mesh and sprayed with cement mortar lining with compressive strength of not less than 30N/mm2. The mix ratio of cement and mortar is: water: cement: sand = 22:20 0:270; Use domestic water; Portland cement; Hard, clean, well-graded natural sand with a mud content of less than 2 and a large particle size of less than 1.2mm. Rust removal: After the acceptance of steel pipe installation, welding, backfilling, vertical displacement, etc., the steel wire wheel brush is used to thoroughly remove the floating rust, oxide skin, welding slag, oil and so on inside the pipeline. Bunzha galvanized wire mesh: lay a diameter of 3mm wire mesh, mesh size 50mm×50mm, mesh spacing 10mm, steel pipe bottom arc length 1380mm range do not lay wire mesh, in order to facilitate the spraying car walking; Between the wire mesh and the pipe wall, the Q235 steel bar with diameter φ6 and length of 7mm is spot-welded, the spacing is 350mm, and the inner wall of the steel pipe is 9mm from the surface of the iron wire. Mechanical spraying cement mortar: spray in two layers, the first layer is 1012mm thick, the second layer is 810mm, to ensure that the scraping is smooth. Cement mortar lined anti-corrosion steel pipe has the following obvious advantages: 1. To avoid the production of corrosion rust and scale on the inner wall of the pipeline, the pipeline can maintain a good state of water transmission for a long time, and the friction coefficient is small. 2. Due to the isolation of the lining coating, the water body is not in contact with the metal pipe, ensuring the water quality. 3. The inner wall of the pipeline is anticorrosive by cement mortar, which prevents corrosion and perforation and prolonging the service life of the pipeline. The material of cement mortar coating is convenient, the construction period is short, the anti-corrosion effect is good, and the cost of pipeline engineering is reduced. In view of the above advantages of cement mortar lined anti-corrosion steel pipe, the function and economy of its anticorrosion are recognized by more and more engineering and technology departments at home and abroad, and cement mortar is used as the main point of anticorrosion in metal water supply pipelines in large and medium-sized cities in China. The state has also formulated specifications and quality standards for cement mortar lining.
Polyethylene wound belt anticorrosion: It is suitable for irregular pipe fitting machine can not operate products, used to replace 3PE anticorrosion. (2023-10-08)
