Cangzhou Shenlong pipeline professional steel surface treatment, for steel shot blasting, spray painting, pickling (steel structure corrosion and rust removal) and other processing methods have a very high level, whether it is steel plate, profile, or other steel structure parts, can be processed, including export steel project packaging, shot blasting spray painting. Heavy anti-corrosion pipe, cement pipe, buried pipe in waterworks, and other services, followed by shenlong to tell you about the type and design of anti-corrosion steel pipe

It is a mature technology for coating the inner wall of water transmission steel pipe and anti-corrosion, and it is also different according to the different lining materials of the medium. But for water pipelines, especially tap water pipelines, the inner wall coating materials must be required to meet the environmental health requirements, in line with the safety of drinking water food grade standards. Although with the development of coating technology, food-grade coatings emerge in endlessly, absolutely safe water-lining coatings have not yet. Even if there are manufacturers known as green pollution-free lined anti-corrosion products, the public is still worried about the harm, because the product is organic materials, and organic materials ultimately affect the health of the public. In order to solve the problem of anticorrosion of tap water pipelines and the harsh condition of health and safety, the anticorrosion technology of coating cement mortar in tap water pipelines is developed accordingly. The emergence of this technology in our country has been more than 30 years, and the author roughly in the anticorrosion construction technology of work time, no matter from technology maturity, the superiority of materials, degree of automation equipment, there is a leap of development and has a mandatory construction quality standards in the buried for shuicheng steel pipeline coating cement mortar lining standard CECS10:89. In this paper, we make a simple superficial exchange and discussion on the anticorrosion technology of cement mortar coating on the inner wall of tap water pipelines, hoping to get some substantive inspiration and application in the anticorrosion construction of water pipelines, especially tap water pipelines, and reproduce the special wind color of inorganic materials in the field of anti-corrosion.

The water pipe is lined with cement mortar anticorrosive layer, which not only plays a simple physical isolation role but also forms a "passivation zone" between the mortar and the metal surface with a PH value of more than 12. Even if tap water reaches the metal surface through the coating (2mm every 10 years), it will not form rust. Comprehensive of many excellent characteristics, the cement mortar lining of the inner wall of the tap water pipeline has the following remarkable advantages:

1. Avoid corrosion and rust on the inner wall of the pipeline, so that the pipeline can maintain a good water delivery state for a long time. The friction coefficient N is small, and the N value of the coating with good quality is between 0.012-0.013, or even smaller.

2. Due to the isolation of the coating in the cement village, tap water is not in direct contact with the metal pipeline, and the cement mortar belongs to inorganic compounds, non-toxic, and has stable performance, to ensure water quality.

3. Good process performance, low requirements for pipe inner wall treatment, general steel wire wheel grinding rust removal can be.

4. Because the cement mortar coating has a certain thickness, it improves the rigidity and permeability resistance of steel pipe, reduces the wall thickness of steel pipe, and reduces the cost of pipeline engineering.

5. Flame cutting, electric welding, or mechanical pipe cutting have little effect on the mechanical strength and corrosion resistance of the cement mortar village layer.

6. The anticorrosion of cement mortar prevents the corrosion and perforation of the tap water pipeline and prolongs the service life of the tap water pipeline.

Process: set up operation table pit site ---- inner wall rust removal ---- coating (small diameter adopts centrifugal spraying, large diameter spraying at the same time) ---- sealing maintenance ---- inspection ---- and put into use.

Quality standard: Diameter of 400 thickness of 6.4 mm 500-700 thickness of 8 mm, a diameter of 800-1000 thickness of 10 mm, and a diameter of more than 1000 mm according to the standard requirements. The coating surface should be smooth, and continuous, with no leakage, no empty drum, and no dew. Trim for the manual, to feel smooth and sensitive.

Material requirements: cement, the selection of ordinary Portland cement or slag cement 425# above, in line with the national standard GB-175-85, factory issued by the quality certificate, beyond the storage period or other reasons, should be sent to the testing department for inspection before use. Yellow sand, industrial sand 40-70 mesh, hard and clean, good grading, impurities, and mud content should not be more than 2%, 14 mesh screen before use. Mixed water, tap water, well water. Additive, (S.T) non-toxic white powder, with a quality certificate and non-toxic test report of concrete products formed by it, its dosage is five-thousandths of cement, used to increase the bonding force between mortar and steel, reduce the axial contraction force.

Cement mortar with weight ratio, cement: yellow sand =1:2 add cement dosage of five-thousandths of additives and adjust the degree of collapse between 70-100 mm.

The main points of construction operation: A, small-diameter pipeline is constructed by a centrifugal shotcrete machine, which is operated on the ground. The shotcrete machine should be installed firmly so that the supported pipeline axis is in A horizontal position. B. Ground and underground construction are divided according to the pipe diameter and the actual situation of the construction site. C. Before construction, the pipes made should be arranged neatly in the ground construction. Pipes with a diameter of more than 1200 can be connected with more than two pipes, and the joints should be well-connected and smooth. D. Before spraying mortar, some impurities such as rust spot welding slag and oxide skin should be removed from the inner wall of the pipeline, and the rust removal should meet the St3 standard. E. Mix mortar. Mortar ingredients should be weighed according to the mixing ratio. F. The mortar ratio should be accurate and evenly mixed. The mixed mortar should be used up within 40 minutes. G, spraying machinery, should be according to the size of the pipe diameter, choose its suitable spray machine, before spraying debugging. H. The thickness of the spraying mortar shall be determined according to the design or the size of the pipe diameter according to the standard. I, the shotcrete machine should be constructed continuously to prevent cement mortar hardening, so that the nozzle of the shotcrete machine is blocked, affecting the construction progress and causing quantity waste. J. After the inner wall of the water pipe is coated with cement mortar, plastic film is applied to seal the pipe mouth and straw bags are used to shade the sun, so as to prevent wind and sun exposure, which may cause premature dehydration of the mortar, resulting in cracks and quality accidents. K. After coating the cement mortar on the inner wall of the tap water pipeline, the temperature in the pipe should be recorded. When the mortar strength reaches the prescribed strength, it should be moistened and cured with water until its strength reaches 100%. L, Steam curing should be carried out when the temperature is below 5 degrees Celsius. M. When a certain amount of cement mortar is sprayed on the inner wall of the tap water pipeline, two groups of cement mortar pressure test blocks should be made. One group should be put into the pipeline for curing at the same time, and the other group should be cured at room temperature. N, after the use of each layer of the shotcrete machine, it should be cleaned, check whether the electrical circuit is correct or not and whether the cable is damaged. O, quality test, thickness control between the standard value of plus or minus 2 mm, using non-magnetic thickness gauge, or local destructive direct measurement. Compressive strength 300Kg per cm square, the use of pre-left standard block pressure test, commissioned detection. Naked eye observation, steel ruler measurement, the inner coating surface should be smooth, smooth, and continuous, with no shell, no hanging slurry, no flow, no leakage coating, and no cracking. The width of the cement mortar coating crack is less than or equal to 1.6 mm, and the axial length along the pipeline is not greater than the circumference of the pipeline length and is not greater than 5 mm and can not be repaired. When the crack width is greater than 1.6 mm, after strengthening the maintenance the crack can be automatically healed, and can be considered qualified, for hemp, sand hole, and an empty nest, each place shall not be greater than 5 cm square, a single defect depth is not greater than 2 mm. The area of each cavity must not be larger than 400 cm square. P, the defect repair material should be the same as the original spray paint, and the repair area should be maintained. For small repair areas, polyvinyl acetate mud should be used to repair, so as to ensure quality and maintenance speed.

Cangzhou shenlong pipe manufacturing co., ltd. Is engaged in oil, gas, water, coal slurry mixing medium steel pipeline coating operations, anti-corrosion, insulation, piping is set in a body's specialized pipeline engineering precast construction enterprises, products used in an oil pipeline, chemical piping, electrical, pipe, gas pipe, heat pipes, sewage pipes, etc. Anti-corrosion processing of straight pipe and bend pipe DN40-3000 three-layer structure polyolefin (PE, PP, TPEP,3LPE) steel pipe coated with anti-corrosion, DN40-3800 steel hot stewed bend pipe and pipe fittings coated with FBE, epoxy resin coating anti-corrosion, DN40-3800 steel pipe inner wall resistance reduction, solvent-free epoxy steel pipe, epoxy paint anti-corrosion, Coated plastic steel pipe, dip plastic steel pipe. They are lined with plastic steel pipe PE,PO, PP, PTFE, HDPE, and polymer polyethylene corrosion. The company is in strict accordance with China Petroleum and Natural Gas SY/T0413-2002, national GB/T23257-2009, German DIN 30670, American AWWA C210, and other international and domestic anti-corrosion standards.