Introduction of ductile cast iron pipe and its anti corrosion meassures

1. Ductile cast iron pipe is a kind of cast iron, is a kind of an alloy of iron, carbon and silicon.
The graphite exists in the form of spherical shape in the ductile cast iron pipe, usually the size of
6-7 level, for the quality, nodulizing grade is required to be controlled between grade 1 and grade
3 (nodulizing rate of 80% or higher), so it can get better improvement on the mechanical
properties of the material itself, has the nature of the iron and the performance of the steel.
For the ductile cast iron pipe after annealing, the microstructure is ferrite and a small amount of
pearlite with good mechanical properties.
Ductile iron pipes are also called centrifugal ductile iron pipe, it has the performance of the
essence of the iron and steel, anti-corrosive performance, good ductility, good sealing effect, easy
to install, it is mainly used for municipal, industrial and mining enterprises, water supply, gas, oil,
etc, is the first selection of water supply pipe, has the very high cost performance.
Compared with PE pipes, from the installation time, ductile pipe is more simple and quick than PE
pipe installation, and the bearing pressure inside and outside is better installed; From the
perspective on the impermeability and corrosion, ductile pipe installed in sealing better, also can
improve the anti-corrosion performance through many kinds of anti-corrosion measures; From the
point of hydraulic performance, because generally refers to the inner diameter ductile pipe
specification, PE pipe specifications generally refers to the outer diameter, because under the
condition of the same specification, ductile pipe can achieve greater runoff; From the point of
comprehensive installation and maintenance cost, ductile pipe has more superior performance.
Wall spray zinc, cement mortar anti-corrosion materials.
Anti corrosive coating
1. Bituminous paint coating
Bituminous paint coating is used for conveying gas pipeline.
Spray paint on the pipe before preheating can improve the adhesion of asphalt paint, accelerate
drying.
2. The cement mortar lining + special coating
Such anti corrosion measure is suitable for transporting sewage pipeline, can improve the
corrosion resistance of lining.
3. The epoxy coal tar coating
Epoxy coal tar coating applies to gas pipelines, can also be applied to sewage pipe.
It is a kind of two-component coating, the coating has good adhesion and very smooth surface
4. Epoxy ceramic lining
Epoxy ceramic lining applied to sewage pipeline and gas pipeline, but due to the manufacturing
process is difficult, high cost, so there are some limitations on use. Epoxy ceramic lined with high
adhesion and bright and clean degree, is a kind of excellent corrosion resistant coating.
5. Coating or sulfate aluminate cement concrete coating
These two kinds of special cement coating are suitable for sewage pipe with the ductile cast iron
pipe corrosion protection, improve the erosion ability of resistance to acid-base components in
sewage.
6. Pu coating
It is a kind of order to adapt itself to the requirements of environmental protection and
development of a new type of green, the special coating, good wear resistance and corrosion
resistance.