Corrosion protection of buried pipes

It can be treated with 3PE anti-corrosion coating or FBE coating

The external anti-corrosion coating for buried pipelines is divided into three grades: ordinary, reinforced, and extra-reinforced. The type of coating and the anti-corrosion grade are determined based on soil and environmental factors. The grades and structures of epoxy coal tar pitch anti-corrosion coatings, as well as the structures of various grades of asphalt glass fiber cloth anti-corrosion coatings, are clearly specified in relevant design manuals; of course, new designs can also be developed based on actual needs. Of course, the key is to carry out construction in accordance with the technical requirements. This is what matters most; otherwise, spending money will not have any anti-corrosion effect. Technical requirements for the anti-corrosion application of epoxy coal tar glass fiber cloth: 1. Substrate preparation – Before applying the primer, the surface of the steel pipes must be treated to remove oils, dirt, existing coatings, and other impurities. The rust removal standard should generally be at least Sa2; the surface must be free of defects such as weld bumps, sharp edges, or burrs. 2. Applying the primer: After the steel pipe surface has been properly treated, the epoxy coal tar primer should be applied as soon as possible, with an interval of no more than 4–8 hours. The paint should be mixed according to the instructions and allowed to mature for 10–30 minutes before application. An area of 100–200 mm at each end of the pipe should remain unpainted. The coating must be even, without any missed areas, bubbles, or lumps, and the dry film thickness should be no less than 25 microns. 3. Plastering: Plaster should be applied to welds and other uneven surfaces to create a smooth transition surface. The putty is made from epoxy coal tar paint and talcum powder, and is applied after the primer has dried to prevent hollowing out when glass fiber cloth is wrapped around it. 4. Standard grade: After the primer or putty has dried, apply the first coat of topcoat evenly, ensuring no areas are missed; the second coat can be applied only after the first coat has fully dried. 5. Reinforced grade: For the reinforced anti-corrosion coating, after applying the first coat of paint, glass fiber cloth is wrapped around it immediately; the cloth should be stretched tightly, with a smooth surface free of wrinkles or bulges. The bead width should be 100–150 mm; thereafter, a second coat of paint is applied, ensuring that the paint coverage is thorough, with all gaps in the glass fiber cloth filled with paint. The third topcoat is applied after the second coat has dried. It is also possible to directly wrap it with glass fiber cloth soaked in epoxy coal tar pitch after the first topcoat has dried, and apply the final topcoat once it has fully cured. 6. Extra-strength grade: For the anti-corrosion coating of the extra-strength grade structure, repeat the process described in the previous point, except that the glass fiber cloth is wrapped in the opposite direction to the previous time; then, after the fourth coat of topcoat has dried, apply the fifth coat. 7. It can only be transported after being left to cure. The technical requirements for applying the asphalt glass fiber cloth anti-corrosion layer are largely similar, aside from boiling the asphalt and covering it with a layer of polyethylene film at the end; therefore, no further details are needed.

Thick-paste epoxy aluminum powder paint can be used, with primer + topcoat； Epoxy coal tar pitch paint + glass fiber cloth can also be used.

We usually use asphalt glass fiber cloth for corrosion protection

After rust removal, wrap it with asphalt-coated glass cloth or provide insulation before burying it in the ground.

Wrapped in glass cloth; it can be made with resin or other materials as well

The plan for the third floor is completely feasible; this is how we proceed, using pre-prepared epoxy coal tar paint.

Polyurethane foam also provides a good anti-corrosion effect these days.

We use polyethylene adhesive tape; just wrap it around, and it’s easy to apply.

For buried pipelines, the anti-corrosion measures to be used depend on the soil composition and the degree of corrosion. The most commonly used methods are: 1) epoxy coal tar pitch, 2) petroleum asphalt, 3) polyethylene tape

Three coats of epoxy coal tar pitch plus two coats of glass fiber cloth

Everything said upstairs is correct. Additionally, for applications with higher requirements, cathodic protection is necessary, which can be achieved either through sacrificial anodes or external current supply

Technical requirements for the anti-corrosion application of epoxy coal tar glass fiber cloth: 1. Substrate preparation – Before applying the primer, the surface of the steel pipes must be treated to remove oils, dirt, existing coatings, and other impurities. The rust removal standard should generally be at least Sa2; the surface must be free of defects such as weld bumps, sharp edges, or burrs. 2. Applying the primer: After the steel pipe surface has been properly treated, the epoxy coal tar primer should be applied as soon as possible, with an interval of no more than 4–8 hours. The paint should be mixed according to the instructions and allowed to mature for 10–30 minutes before application. An area of 100–200 mm at each end of the pipe should remain unpainted. The coating must be even, without any missed areas, bubbles, or lumps, and the dry film thickness should be no less than 25 microns. 3. Plastering: Plaster should be applied to welds and other uneven surfaces to create a smooth transition surface. The putty is made from epoxy coal tar paint and talcum powder, and is applied after the primer has dried to prevent hollowing out when glass fiber cloth is wrapped around it. 4. Standard grade: After the primer or putty has dried, apply the first coat of topcoat evenly, ensuring no areas are missed; the second coat can be applied only after the first coat has fully dried. 5. Reinforced grade: For the reinforced anti-corrosion coating, after applying the first coat of paint, glass fiber cloth is wrapped around it immediately; the cloth should be stretched tightly, with a smooth surface free of wrinkles or bulges. The bead width should be 100–150 mm; thereafter, a second coat of paint is applied, ensuring that the paint coverage is thorough, with all gaps in the glass fiber cloth filled with paint. The third topcoat is applied after the second coat has dried. It is also possible to directly wrap it with glass fiber cloth soaked in epoxy coal tar pitch after the first topcoat has dried, and apply the final topcoat once it has fully cured. 6. Extra-strength grade: For the anti-corrosion coating of the extra-strength grade structure, repeat the process described in the previous point, except that the glass fiber cloth is wrapped in the opposite direction to the previous time; then, after the fourth coat of topcoat has dried, apply the fifth coat. 7. It can only be transported after being left to cure. and glass fiber cloth