Pipe anti-corrosion
The anti-corrosion of welded pipe is in accordance with the requirements of drawings, using epoxy coal asphalt paint wrapped with glass cloth and top coat for anti-corrosion.
1. Pipe descaling: Before applying primer, the surface of pipe should be cleared of grease, grey residue, rust and iron oxide. The quality standard of rust removal by sand blasting reaches Sa2.5 level.
2. After removing rust on the surface of pipe, apply primer, the time interval between them should not be more than 8 hours, when applying primer, the base surface should be dry. The primer should be painted uniformly and fully, and there should be no clumping and blistering phenomenon, and the two ends of the tube should not be painted within 150~250mm.
3. primer surface drying after painting the top coat and wrapping glass cloth, primer and the first top coat painted at intervals of not more than 24 hours.
4. Epoxy coal asphalt paint using two-component, room temperature curing paint: glass cloth using dry, dewaxed, untwisted, sealed edges, medium alkali, warp and weft density of 10 * 12 roots / cm ~ 12 * 12 roots / cm of glass cloth. Immediately after the top coat is applied, the glass fabric is wrapped, the crimp width of the glass fabric is 30~40mm, the joint lap length is not less than 100mm, and the lap joints of each layer are staggered with each other. The oil penetration rate of glass fabric is more than 95%, and there shall not be any blank larger than 50mm*50mm, and the pipe end shall be left with 150~250mm stepped stubble.
5. pipe interface construction should be carried out after the welding test pressure, new and old anti-corrosion crimping is not less than 50mm, the joint lap length shall not be less than 100mm, the stubble should be bonded firmly, tightly.
6. the outer wall of the steel pipe coating mechanism: a bottom two sides of a cloth two sides, the total thickness of the dry film 400um.
7. the inner wall of the steel pipe coating mechanism: a bottom three sides, the total thickness of dry film 300um.
8. After the construction of external anticorrosion is completed, the quality inspection is carried out according to the design requirements or relative requirements.
