Strengthening anticorrosion treatment fo
发布日期:2018/04/11
How to deal with the reinforced anticorrosion treatment of directly buried pipeline:
First, ordinary fire fighting pipeline anticorrosion practice: first coat a primer, then coat three layers of topcoat.
Two, strengthen the anti-corrosion practice of the grade fire pipe: first coating a layer of primer, then coating the finish, and then adding glass cloth, then coating the face paint, wrapping a layer of glass cloth, and then applying two layers of finish.
Three, special strengthening grade fire pipeline anticorrosion practice: first coating a layer of primer, then coated with a coat, wrapped a layer of glass cloth, then coated with a paint, a layer of glass cloth, then coated with a varnish, a layer of glass cloth, then two layers of finish.
The steel structure such as pipes, pipe supports and so on are all cleaned by sand blasting.
When sand blasting is used, the rust removal is arranged in the anticorrosion factory. The quality grade of the rust removal is Sa2.5 grade, in order to ensure the quality grade of the rust removal, the spray abrasive material is quartz sand, the water content is less than 1%, the grain size is all through the 7 sieve number, the 20 sieve number is not less than 40%, and the 45 sieve number is not passed.
The spraying angle, the speed of the spray gun and the spray distance should meet the requirements, and the surface roughness of the sand blasting surface is more consistent, which not only increases the adhesion of the coating, but also ensures the surface roughness.
B) mechanical rust removal.
The rust removal of the installed weld parts adopts the mechanical dynamic derusting mode of the grinder, and the rust removal level is up to St3 grade.
4.1.2.2 primer and lacquer in front of glass cloth
A) anticorrosive epoxy coal tar paints are painted in accordance with the site conditions.
B) the rust removal of steel after inspection is qualified to paint the primer and topcoat. When the coating is painted, the weld position of the steel assembly is left out as much as possible. The reserved length is about 150mm, so as to avoid the difficult to clear the root and affect the quality of the welding.
C) for steel surface pits and dust (greater than 2mm), it should be mixed with putty.
D) mix the epoxy coal tar paint, mix it up and make it 15 to 30min, and use it in 4 hours.
E) the primer is painted with the first coat before drying and solidified before finishing. After finishing the finish, second topcoat is applied before curing. During construction, it is often continuous on the process flow, so special attention should be paid to the painting interval between the paint and the interval between the minimum and maximum coating intervals. The interval time of painting should be determined according to the performance and weather conditions of the coating.
F) if the paint coating interval is too long, you need to paint the surface with abrasive cloth or grinding wheel shaving after after brushing paint.
G) when the steel is qualified, the primer should be brushed immediately. Therefore, the effect of dust on the paint should be paid attention to at the same time. As far as possible, the coating area or the construction of sand blasting should be taken as far as possible.
H) the operation of epoxy coal tar paints shall be carried out according to the specifications and specifications of the materials arrived with the goods.
I) painting equipment should be clean, proper cleaning and disposal after use.
J) when the brushing is done, the layers are crisscrossed, each layer reciprocating. The paint interval should meet the technical requirements of the coating, and the thickness of the film meets the design requirements. During the drying process, the paint film should keep the surrounding clean and prevent the paint surface from being polluted.
4.1.2.3 winding glass cloth
A) the winding of the glass cloth should be carried out immediately after the second topcoat is painted. Strengthen the epoxy coal tar anticorrosion as required, winding a layer of glass cloth.
B) the pressure side edge 15 ~ 25mm winding glass cloth, lap joints of 100 ~ 150mm.
C) if there is bubbling when wrapping, use a knife to cut it, then squeeze out the air in the bubble and smooth the surface.
D) the winding of the entire glass cloth should be uniform and smooth.
4.1.2.4 topcoat brush
A) when the glass cloth is wrapped, the paint is immediately painted. The finish of the coat is painted two.
B) when painting the top coat, make sure that the coating is covered with no coating and pinhole.
C) the coating ensures that the glass cloth is completely covered.
4.1.2.5 drying and maintenance
After the pipe is finished, it is allowed to stand on its own to dry. At least 8h can not be moved, so that it can not be raining or soaking.
Repairing and filling of 4.1.2.6 pipeline anticorrosion layer
In the course of transportation and installation of pipeline, the damage of pipe anticorrosion layer may occur. After the installation of pipeline is completed and the acceptance of the pipeline is qualified, it is necessary to repair the pipe anticorrosion layer.
A) the rust on the surface of the steel on the surface of the steel is dermabrasion or manual rust removal, and the rust removal level should be above St3 grade.
B) because of its complexity and inconvenient operation, it is easy for the inspectors to neglect the repair site. The construction personnel should pay special attention to the quality assurance.
C) the anticorrosive coating used for the corrosion protection and repair of the pipeline should be consistent with the anticorrosive layer of the adjacent pipelines. The new and old coating anticorrosion layer Jiecha a ladder, the interface must overlap. The lap is kept at least 50mm.