Buried pipe external corrosion
Shot blasting: spray steel shot rust Sa5 restraint, rust, metal appearance of heavily exposed silver-white metallic luster, surface roughness of 40 ~ 70μm.
Spray coating: strengthen the special grade coal tar epoxy, or a primer, cheek 5, the center clip four layers of epoxy glass cloth, 0.9 ~~ 1mm thickness, coated with the paint painted on each paint the interval drying up the sticky subject.
Quality check: from visual inspection, paint the appearance of uniform, smooth, no sagging, no bubbles, no wrinkles. Application thickness gauge, sampling 5 percent, fully measured to achieve the design thickness, or thicken up painting. Held at the 5000V spark pinhole leak detector, pinhole and insulation check for qualified non-sparking. Adhesion to check the coating cut triangular mouth, held tearing force should be difficult to pull up; if pulled up, but the first layer of primer must be attached to the pipe metal appearance, so to be qualified.
External corrosion of carbon steel pipe out tube
Using the STIC heavy-duty coatings.
Shot blasting: all child pipe rust.
Spray anti-corrosion coatings: When rust qualified, using airless high pressure spray gun to spray the first layer of red primer until the paint to dry non-stick hand, and then spray the end of the second film thickness of 300μm.
Paint inspection: visual inspection, all child thickness measured using a magnetic thickness gauge held measurement, the total film thickness of more than 600μm.
Internal coating pipes
Buried pipes and penstocks within the anti-corrosion, are used to hang galvanized barbed wire, spray compressive strength of not less than of 30N/mm2 the cement mortar lining. Cement mortar mix ratio, water: cement: sand = 22:200:270; use of domestic water; # 525 Portland cement; rigid, clean, well-graded natural sand, clay content is less than 2% particle size less than 2mm.