Ductile iron pipe is a pipe made by casting molten iron above No. 18 after adding a nodularizer, and then centrifuged at a high speed by a centrifugal ductile iron machine. It is referred to as ball pipe, ductile iron pipe, and ductile cast pipe. , silicon, manganese, sulfur, phosphorus and magnesium. Ductile iron pipe is also an ideal material for tap water pipes, and its main purpose is naturally to transport tap water.
Secondly, we must know what are the characteristics of ductile iron pipes. As the name suggests, ductile iron pipes are one of the cast iron pipes. In terms of quality, the nodularization grade of cast iron pipes is required to be controlled at 1-3, that is, the nodularization rate is not high. Less than 80%, so the mechanical properties of the ductile iron pipe material itself can be better improved, so that it has the essence of iron and the performance of steel. After annealing, the metallographic structure of the ductile iron pipe is ferrite plus a small amount of pearlite, which makes it have the characteristics of good mechanical properties, excellent anti-corrosion performance, good ductility, good sealing effect, and easy installation. In addition, in the medium and low pressure pipe network, the ductile iron pipe has the advantages of safe and reliable operation, low damage rate, convenient construction and maintenance, and excellent anti-corrosion performance, but there are also some shortcomings, such as low pressure resistance in the high pressure pipe network, so generally Not used; the pipe body is relatively heavy, so machinery must be used during installation; if water leakage occurs after the pressure test, all pipes must be dug out, and then the pipes must be lifted to a height that can be placed in the clamps, and the clamps must be installed Hoop to stop water leaks.
In all urban water supply and drainage pipe network systems, ductile iron pipe is a relatively safe and reliable pipe material. Ductile iron pipes are very suitable for use in elbows, tees and corresponding flange connections. Compared with ordinary pipes, in terms of quality, ductile ink tubes have two main advantages, one is long service life, and the other is strong corrosion resistance. In combination, that is to say, under correct installation and construction water quality and use conditions, ductile ink tubes have two main advantages. The service life of the tube can reach 50 years, and the maintenance is very convenient. Then there are the issues of price and environmental protection. It is cost-effective and more environmentally friendly than plastic pipes.
After understanding the intrinsic characteristics, it is also necessary for us to understand the appearance and performance of ductile iron pipes. Ductile iron pipes are called centrifugal ductile iron pipes. They are mainly used for water supply, gas transmission, and oil transportation for municipal and industrial and mining enterprises. They are the first choice for water supply pipeline materials, so they have high cost performance.
Finally, we must pay attention to the anti-corrosion treatment of ductile iron pipes. It mainly includes the following methods:
1. Coating with green paint, this method is suitable for pipelines that transport gas. Also, preheating the pipes prior to painting improves asphalt paint adhesion and thus speeds up drying.
2. Lining with cement mortar and adding a special coating, this method is suitable for pipelines that transport sewage, and can improve the corrosion resistance of the lining.
3. Coating with epoxy coal tar pitch, this method is suitable for both gas pipelines and sewage pipelines, the coating has high adhesion and a very smooth surface.
4. Lining with epoxy ceramics, this method is suitable for sewage pipelines and gas pipelines, but its manufacturing process is difficult and costly, so it has certain limitations in use. Epoxy ceramic lining is an excellent anti-corrosion coating with high adhesion and smooth finish.
5. Coating with aluminate cement or sulfate cement coating, this method is suitable for the internal anticorrosion of ductile iron pipes used in sewage pipelines, and can improve the ability to resist the erosion of acid and alkali components in sewage.
6. Polyurethane coating is a new type of green special coating developed to meet the needs of environmental protection. It has good wear resistance and corrosion resistance.
Post time: Apr-25-2023