Spiral welded pipes (SSAW) for water conservancy projects are generally spiral welded steel pipes with relatively large diameters, because the water passing through per unit time is large, which can greatly improve work efficiency. Since the inner wall of the spiral steel pipe is constantly washed by water, the inner wall is generally not treated with anti-corrosion treatment, but the exterior is generally in the form of overhead, so anti-corrosion needs to be done to deal with rain erosion and sun exposure, so the requirements for anti-corrosion coatings are higher.
Before anticorrosion of spiral steel pipes for water conservancy projects, the surface of the steel pipes should be sandblasted, and the grade should reach st2.5. After sandblasting, apply the anti-corrosion primer immediately. The anti-corrosion primer is generally epoxy zinc-rich paint with a zinc content of 70% or more, the middle is epoxy mica paint, and the outermost layer is anti-oxidation and corrosion. Polyurethane paint.
Before leaving the factory, the spiral steel pipe should be tested for mechanical properties, flattening and flaring, and must meet the requirements of the standard. Spiral welded steel pipes have greater flexibility in the range of diameter and wall thickness specifications, especially in the production of high-grade thick-walled pipes, especially small and medium-diameter thick-walled pipes. There are more requirements in terms of spiral steel pipe specifications. The diameter and size specification range of the spiral steel pipe should be flexibly controlled.
The implementation of anti-corrosion engineering must meet the following conditions before it can be implemented:
First, the plan and other technical documents are complete, and the construction drawings must be jointly reviewed. Second, the technical disclosure of the construction plan is completed, and safety technology teaching and necessary technical training are implemented. Third, all equipment, pipe fittings and fittings must have a factory certificate, or a corresponding account certificate. Fourth, the materials, machinery, construction equipment and site are thorough. Fifth, there must be reliable protective equipment that is safe and reliable, and construction water, electricity, and gas must be able to meet continuous construction needs.