Application of anti-corrosion coatings in the construction of serum-erki water pipelines

Song Tieding, Mao Jiansheng
(Yellow River Engineering Administration of Inner Mongolia Autonomous Region, Inner Mongolia Estuary 015200)
(Summary) using two-part white non-toxic epoxy
cetomar coating
and two-part The cold entanglement belt of epoxy coal drainage is anti-corrosion of the inner and outer walls of the spiral welding pipe pipeline, and it provides cooling water for power generation through water transfer, sand storage and pressurized engineering.
(keywords) water pipeline internal and external wall anti-corrosion; Epoxy ceramics
coatings
; Epoxy coal leaching cold strap application
in the figure classification number: TV47 article identification code: A article number: 1009-0088 (2012) 05-0087-02
1 Basic situation
1 .1 Project Overview
The Red Flower Erki water supply project, with the Red Flower Erki water conservancy hub as the source, through a 69km long water supply pipeline to transport water, sand storage, pressurized project, for the Emin power plant, Lunen Ewink power plant to provide industrial water, but also for Hulunbel City to provide a living backup water source.
1.2 Engineering Task
This project is located in the lower reaches of the hub grassland, the main task is to do internal and external anti-corrosion of spiral welding pipes in the pipeline, the inner wall anti-corrosion using two components of white non-toxic epoxy ceramic coating, its Model GH102 type A, B parts, the outer wall corrosion protection using two-part epoxy coal leaching cold entanglement belt, construction of a corrosion-resistant steel pipe length of 12000mm
China
.
1.3 construction process
the use of anti-corrosion construction process, this anti-corrosion steel pipe specifications have DN2020×18×12000mm, DN142 0×12×12000mm, DN1220×12×12000mm, DN1020×10× 12000mm, DN820×10×12000mm, DN720×9×12000mm, DN 630×9× 12000mm, DN530×9×12000mm and other 8 specifications of steel pipe and the corresponding specifications of various pipe inside and outside corrosion protection.
2. Production technology process of anti-corrosion steel pipe
2.1 non-toxic epoxy ceramic screw welding steel pipe lining construction process flow chart
non-toxic epoxy ceramic screw welding steel pipe lining construction process, see Figure 1.Non-toxic epoxy ceramic spiral welding steel pipe lining construction process
2.2 epoxy coal asphalt belt steel pipe outside anti-corrosion construction process
Enoxy coal asphalt winding steel pipe external anti-corrosion construction process
3. Anti-corrosion steel pipe main technical performance indicators
according to the tender documents and design requirements, anti-corrosion pipe manufacturing using "epoxy coal asphalt cold belt technical standards" and "epoxy ceramic coating technical standards" inspection and acceptance. Its main performance indicators are required, as in Table 1, Table 2.Anti-corrosion coatings
application in the Red Flower Erki pipeline projectAnti-corrosion coatings in the Red Flower Erki water pipeline project application
4. Engineering Construction
4.1 Construction Preparation
(1) The anti-corrosion steel pipe production for the site production project, by the project department technical staff in accordance with the approved construction organization program design of the production shift, preparation of production tasks, project engineers approved production tasks.
(2) the project manager presides over the production transfer meeting, to the production team leader issued the production task letter, project engineers and technical personnel to carry out technical, quality, safety. Pre-job training shall be carried out by technical personnel at all levels and the persons in charge of each section.
(3) production team leader to arrange the person in charge of each section to carry out picking, ingredients, commissioning, test drive head to do a good job of production preparation.
(4) the production person in charge to lead the anti-corrosion section operators, inspection, maintenance, commissioning of the production line, project engineers to the production line to carry out a comprehensive inspection and acceptance.
(5) The main operator cooperates with professional electricians and fitters to inspect all motors and electrical equipment of the production line equipment, and to fill and tighten all operating equipment to ensure that all electrical systems, transmission systems and blasting systems work properly.
(6) after confirming that the operators of each section are ready, the person in charge of production shall bring good protective equipment and supplies into the production line according to the anti-corrosion management specifications issued by the production task letter.
4.2 anti-corrosion steel pipe production and quality inspection
(1) the main operator first of all on the site steel pipe surface pre-treatment, remove the steel pipe inside and outside the surface of the steel pipe solder slag, burrs, grease and other dirt, and then use pressure of 0.6 to 0.8MPa air compressor air pressure, sand blaster spray diameter 0.2mm steel sand, has been up to the corrosion platform of the steel pipe blasting work. According to the pipe diameter size adjustment blasting speed, sand blasting rust treatment is completed, the field supervision engineer in accordance with the rust removal standards: the inner wall reached Sa2.5 level, the outer wall reached Sa2 level, after the inspection passed, the steel pipe can be transported to the designated location, the next step of the process. Otherwise, continue sand blasting and rust removal until quality standards are met.
(2) for the steel pipe that has been blasted qualified, the epoxy ceramic coating should be sprayed as soon as possible. Spraying to keep the paint thin and uniform once live, there must be no leakage site, on-site supervision personnel with wet film instrument testing paint spray thickness must reach 280 to 320 m. After the epoxy ceramic coating is air-dried and cured, the supervision personnel in accordance with the "epoxy ceramic coating technical standards" on the steel pipe inner wall epoxy ceramic coating anti-corrosion layer thickness, coating is flat clean, smooth and other items, inspection, qualified, before entering the next process construction. For the spray thickness is not enough parts, should be re-sprayed, after the test qualified.
(3) to the internal spraying of qualified steel pipe, steel pipe external coating glue, plastic before the surface of the steel pipe must be dry, requiring a sufficient amount of glue, no leakage. Immediately after applying the glue wrapped epoxy coal asphalt cold tangle, the connection width of 20 to 25mm, must be cold strap tight, so that the cold tape and the outer wall of the tube close contact, surface flat no drum bag, part of the glue from the cold tape surface seepage (otherwise indicates insufficient amount of glue), the tape immediately after the tape in the uniform brushing a layer of molding glue. Brush construction is completed, by the supervision personnel in accordance with the "epoxy coal asphalt cold band technical standards" external anti-corrosion layer thickness, steel pipe outside the cold band is flat and uniform, steel pipe at both ends of the weld distance is uniform, whether there are obvious scratches, appearance should be clean and other items, after inspection qualified, can enter the finished product area stacking.
(4) anti-corrosion layer wrapped in self-drying, at least 8h to keep no rain, no water. After the anti-corrosion layer is dried, the electric spark detector, in accordance with the Chinese oil and gas industry standard SY/T0447-96 specified leakage detection voltage, that is, to strengthen the stage (0.4mm) with 2500V, check the paint uneven or leakage of a small number of pinholes formed by the pinhole with chalk ring mark and as soon as possible to apply a fixed glue to fill in the leak.
4.3 Temporary storage and protection of finished anti-corrosion steel pipes
For inspection and acceptance of the delivery of finished anti-corrosion pipes, the project department arranged for a special person to manage, special vehicles sent to the installation site. Finished anti-corrosion pipe lifting transport must be properly protected, the use of special lifting belt for loading and unloading, not only to protect the steel pipe port ramp, but also can not damage the protective layer. After the inspection of qualified anti-corrosion finished products tube to do a good job of protection, to ensure that the quality of finished products before delivery and installation is safe and reliable.
4.4 interface and pipe parts on-site corrosion protection
(1) site interface corrosion protection must be in the pipeline installation project segment pressure test or the overall pressure test after the end of the experience received by the engineering supervision personnel formally informed to allow anti-corrosion operations, before the construction work can be arranged.
(2) In order to ensure the anti-corrosion quality and job safety of the site joints, before construction, by the engineering supervision co-installation or pipe ditch civil construction units to dig the work pits in advance, the project department connectors responsible for timely to the site to coordinate the acceptance of whether the work pits meet the work requirements and safety requirements, such as the work pits have groundwater, need to implement drainage measures before the operation.
(3) interface anti-corrosion work steps: (1) clean the interface steel pipe or pipe surface, end surface and cold straps to connect the water, impurities, keep the job site clean, and then apply glue wrapped cold tape, and then apply glue. (2) the internal interface corrosion protection should also keep the end face clean, if necessary, with manual rust remover surface treatment, before applying epoxy ceramic paint, the port after the coating should be smooth and smooth. (3) According to the design requirements of the pipe port, pipe surface corrosion treatment, anti-corrosion work should be carried out in accordance with the standards of procedures. (4) After the on-site joint and pipe anti-corrosion operation is completed, the team self-inspection is qualified, the inspector conducts on-site acceptance, and fills in the inspection report form, asks the supervising engineer and the owner's representative to carry out on-site acceptance, handles delivery and confirms the amount of the project.
5. Anti-corrosion steel pipe production quality control measures
5.1 surface blasting effect inconsistent prevention and control
before sand blasting, must check whether the blasting equipment is good to use, steel sand is in line with the machine use standards, used angled steel sand must not be repeatedly used, otherwise there will be inconsistent effect of blasting effect.
5.2 spraying or brush uneven prevention and control
first check whether the sprayer is good to use, spray pressure is normal, spray gun head is blocked phenomenon, paint is stirred evenly, paint heating is up to the required temperature.
5.3 Cold tangle winding uneven prevention and control
First check whether the cold winding belt rotating machine is normal, speed is uniform, winding machine will be cold band tight, applying glue is uniform, applying glue is qualified for good use.
6. Anti-corrosion pipeline project operation effect
the project through 1 year of operation, pipeline water transmission normal, through fixed-point sampling inspection, did not find drip, leakage and running water and other phenomena occurred, by the local quality supervision department inspection and acceptance, agreed that the use of anti-corrosion materials in the pipeline has an extremely good effect. This fully proves that the use of two-part white non-toxic epoxy ceramic coating and two-group epoxy coal leaching cold entanglement belt, the spiral steel pipe pipe internal and external anti-corrosion construction, the effect is good, can be applied in other projects to promote.
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