3PE anti-corrosion steel pipe use

Before the painting of the buried pipeline, the surface is blasted. The cleanliness and surface roughness of the treated metal surface must meet the specifications. 1.1 The relative humidity of the air should be lower than 70%, and the surface temperature of the base metal should not be lower than -3 ℃. 1.2. In adverse climates, effective measures should be taken, such as heating and covering, to meet the requirements of the working environment. 1.3. The surface of the buried pipeline before corrosion protection must be free of edges, no welds, smooth and thorny. 1.4. The metal surface treatment is blasting and rust removal to Sa2.5 level. The standard is: completely remove all debris, such as grease, oxide scale, rust products on the metal surface, visible shadow stripes, marks and other residues should not exceed the unit 5% of the area. 2. Pipeline anti-corrosion 2.1, primer and top coat before wrapping glass cloth ***, anti-corrosion epoxy coal asphalt paint construction adopts brush and roller coating methods according to site conditions. 2.1.2. After the derusting of the steel is qualified, paint the primer and topcoat. When painting, leave the welding seam of the steel assembly as far as possible. The reserved length is about 150mm to avoid difficulty in cleaning the root and affecting the welding quality. . 2.1.3. If the degree of pit dust on the steel surface is large (> 2mm or more), putty should be mixed to make it up. 2.1.4. Mix the epoxy coal tar pitch paint and mix it well, then ripen it for 15 to 30 minutes and use it up within 4 hours. 2.1.5. After the primer is dry, apply a top coat before curing, and after the primer is dry, apply a second coat before curing. During construction, the process flow is often continuous, so special attention needs to be paid to the paint painting interval to ensure that the painting interval is between the minimum and large painting intervals. During on-site construction, the coating interval should be determined according to the performance of the paint and weather conditions. 2.1.6. If the paint overcoating interval is too long, the paint surface needs to be roughened with emery cloth or grinding wheel before applying the back coat paint. 2.1.7. Primer should be applied immediately after the pipeline is qualified for sandblasting. Therefore, attention should be paid to the influence of dust on the paint. Keep as far away from the sandblasting area as possible or suspend sandblasting construction.