The pipes made by casting molten iron above No. 18 and adding a nodularizing agent through high-speed centrifugal casting of a centrifugal ductile iron machine are called "ductile iron pipes", referred to as ball pipes, ductile iron pipes, and ductile iron pipes for short. Compared with cs seamless pipes, ductile iron pipes are more suitable for the transportation of tap water, and are ideal materials for tap water pipes.
Features of ductile iron pipes:
Ductile iron pipe is a kind of cast iron pipe. In terms of quality, it is required that the spheroidization level of cast iron pipes be controlled at 1-3 levels, so it can be better improved, with the essence of iron and the performance of steel. The metallographic structure of the annealed ductile iron pipe is ferrite plus a small amount of pearlite. Good mechanical properties, excellent anti-corrosion performance, good ductility, good sealing effect, easy installation, mainly used for water supply, gas transmission, oil transportation, etc. in municipal and industrial and mining enterprises.
A certain amount of spherical graphite is distributed on the ferrite and pearlite matrix. According to the different nominal diameter and elongation requirements, the proportion of ferrite and pearlite in the matrix structure is different. The proportion of pearlite in small diameter is generally not more than 20%, and the proportion of pearlite in large diameter is generally controlled at about 25%.
Mechanical properties
Minimum tensile strength: 420/Mpa
Minimum yield strength: 300/Mpa, minimum elongation 7%
Standard: GB/T13295-2013, ISO2531-2009
Caliber: DN80-DN2600
Advantages and disadvantages
1. Advantages
In the medium and low pressure pipe network (generally used below 6MPa), the ductile iron pipe has the characteristics of safe and reliable operation, low damage rate, convenient and fast construction and maintenance, and excellent anti-corrosion performance.
2. Disadvantages
Generally not used in high pressure pipe network (above 6MPa). Because the pipe body is relatively bulky, machinery must be used during installation. If there is water leakage after the pressure test, all the pipes must be dug out, the pipes must be hoisted to a height where they can be placed in the clamps, and the clamps should be installed to prevent water leakage.
Compared with carbon steel pipes, the manufacturing process of ductile iron pipes is more complicated and the cost is more expensive, but its corrosion resistance and pressure resistance life is longer than carbon steel pipes, more than 70 years.
Features of ductile iron pipes:
Ductile iron pipe is a kind of cast iron pipe. In terms of quality, it is required that the spheroidization level of cast iron pipes be controlled at 1-3 levels, so it can be better improved, with the essence of iron and the performance of steel. The metallographic structure of the annealed ductile iron pipe is ferrite plus a small amount of pearlite. Good mechanical properties, excellent anti-corrosion performance, good ductility, good sealing effect, easy installation, mainly used for water supply, gas transmission, oil transportation, etc. in municipal and industrial and mining enterprises.
A certain amount of spherical graphite is distributed on the ferrite and pearlite matrix. According to the different nominal diameter and elongation requirements, the proportion of ferrite and pearlite in the matrix structure is different. The proportion of pearlite in small diameter is generally not more than 20%, and the proportion of pearlite in large diameter is generally controlled at about 25%.
Mechanical properties
Minimum tensile strength: 420/Mpa
Minimum yield strength: 300/Mpa, minimum elongation 7%
Standard: GB/T13295-2013, ISO2531-2009
Caliber: DN80-DN2600
Advantages and disadvantages
1. Advantages
In the medium and low pressure pipe network (generally used below 6MPa), the ductile iron pipe has the characteristics of safe and reliable operation, low damage rate, convenient and fast construction and maintenance, and excellent anti-corrosion performance.
2. Disadvantages
Generally not used in high pressure pipe network (above 6MPa). Because the pipe body is relatively bulky, machinery must be used during installation. If there is water leakage after the pressure test, all the pipes must be dug out, the pipes must be hoisted to a height where they can be placed in the clamps, and the clamps should be installed to prevent water leakage.
Compared with carbon steel pipes, the manufacturing process of ductile iron pipes is more complicated and the cost is more expensive, but its corrosion resistance and pressure resistance life is longer than carbon steel pipes, more than 70 years.
