Your Professional Ductile Iron Piping Supplier
ROCKERHILL is established in China from 2011 originally, with 15 years of development and improvement, today ROCKERHILL has formed the core businesses in design and engineering, manufacturing and modularization, contracting and services in water conservation and water treatment industry.With a manufacturing hub of 17,000 square meters in JiangSu China, and more than 30 professional technical staffs, and 20 professional senior engineers and national registration engineers, we provide sustainable values and services to our domestic and international customers by utilizing our extensive experiences and integrated competitiveness in design and engineering, technical package, procurement services and project contracting.
-
![Ductile Iron Pipes]()
Ductile Iron PipesDuctile iron(DI) pipe has been the choice for modern water and wastewater systems. It has excelled in strength, durability, and reliability for transporting raw and potable water, sewage, slurries, and process chemicals.view more -
![Ductile Iron Fittings]()
Ductile Iron FittingsDuctile iron fittings are pipe components made from ductile iron (also called nodular cast iron), a type of cast iron that has been treated with magnesium or cerium to enhance its strength and flexibility.view more
Ductile Iron Pipes
Ductile iron pipe is pipe made of ductile cast iron commonly used for potable water transmission and distributionThe pipe is manufactured using centrifugal casting in metal or resin lined moulds.Protective internal linings and external coatings are often applied to ductile iron pipes to inhibit corrosion: the standard internal lining is cement mortar and standard external coatings include bonded zinc, asphalt or water-based paint. In highly corrosive environments loose polyethylene sleeving (LPS) to encase the pipe may also be used.
|
DN (mm) |
Outside Diameter (mm) |
Wall Thickness (mm) |
Approximate Weight of Socket (kg) |
Weight of Straight Section (kg/m) |
Weight of Each Unit (kg/6m) |
Preferred pipe pressure classes |
|||
|
K9 |
C |
K9 / C |
K9 |
C |
K9 |
C |
|||
|
80 |
98 |
6 |
4.4 |
3.4 |
12.2 |
9.1 |
77 |
59 |
C40 |
|
100 |
118 |
6.1 |
4.4 |
4.3 |
15.1 |
11.1 |
95 |
71 |
C40 |
|
125 |
144 |
6 |
4.5 |
5.7 |
18.7 |
14.1 |
118 |
90 |
C40 |
|
150 |
170 |
6.3 |
4.5 |
7.1 |
22.8 |
12.5 |
144 |
106 |
C40 |
|
200 |
222 |
6.4 |
4.7 |
10.3 |
30.6 |
22.6 |
194 |
145 |
C40 |
|
250 |
274 |
6.8 |
5.5 |
14.2 |
40.2 |
32.6 |
255 |
211 |
C40 |
|
300 |
326 |
7.2 |
6.2 |
18.6 |
50.8 |
43.9 |
323 |
282 |
C40 |
|
350 |
378 |
7.7 |
6.3 |
23.7 |
63.2 |
51.9 |
403 |
335 |
C30 |
|
400 |
429 |
8.1 |
6.5 |
29.3 |
75.5 |
60.8 |
482 |
395 |
C30 |
|
450 |
480 |
8.6 |
6.9 |
38.3 |
89.7 |
72.3 |
577 |
476 |
C30 |
|
500 |
532 |
9 |
7.5 |
42.8 |
104.3 |
87 |
669 |
566 |
C30 |
|
600 |
635 |
9.9 |
8.7 |
59.3 |
137.3 |
120.6 |
883 |
784 |
C30 |
|
700 |
738 |
10.8 |
8.6 |
79.1 |
173.9 |
142 |
1123 |
932 |
C25 |
|
800 |
842 |
11.7 |
9.6 |
102.6 |
215.2 |
176.9 |
1394 |
1165 |
C25 |
|
900 |
945 |
12.6 |
10.6 |
129 |
260.2 |
215.5 |
1690 |
1422 |
C25 |
|
1000 |
1048 |
13.5 |
11.6 |
161.3 |
309.3 |
262.1 |
2017 |
1759 |
C25 |
|
1100 |
1152 |
14.4 |
12.6 |
194.7 |
362.8 |
313.55 |
2372 |
2103 |
C25 |
|
1200 |
1255 |
15.3 |
13.6 |
237.3 |
420.1 |
369.1 |
2758 |
2482 |
C25 |
|
1400 |
1462 |
17.1 |
- |
385.8 |
547.2 |
- |
3669 |
- |
- |
|
1500 |
1565 |
18 |
- |
474.9 |
616.7 |
- |
4175 |
- |
- |
|
1600 |
1668 |
18.9 |
- |
526 |
690.3 |
- |
4668 |
- |
- |
|
1800 |
1875 |
18.4 |
- |
702 |
850.1 |
- |
5803 |
- |
- |
|
2000 |
2082 |
20 |
- |
909.9 |
1026.3 |
- |
7068 |
- |
- |
Machinability
Ductile iron pipes can be bent or cut without producing chip-breaking effects. The silicon and graphite content in ductile iron offers flex, lubrication, and abrasion resistance during manufacturing. Compared to steel pipes, the ductile iron pipes present several advantages during machining, including higher productivity, extended tool life, faster spindle speed, and reduced cost of operation.
Safety and Reliability
Other pipeline materials, such as PVC, can experience catastrophic failures due to ground movement and high pressures. For potable water pipelines, this failure presents the risk of drinking water contamination. Ruptured wastewater pipes can also contaminate the surrounding environment.
Corrosion Resistance
Various studies and field tests confirm that the longevity and corrosion resistance of ductile iron pipes exceeds that of cast iron. According to a report by the American Water Works Association (AWWA), the service life of a ductile iron pipe is expected to be over 100 years. This outlasts any other pipeline material used in water and wastewater infrastructure.
Easy Installation
Due to its flexibility and strength, the installation of ductile iron pipes is easier and less expensive than other pipe materials. For example, the strength and flexibility of ductile iron pipes allow them to be installed with less stringent bedding and backfill specifications.
Cost-Effectiveness
Standard ductile iron pipes also have internal diameters that are larger than other standard pipe materials. Additionally, the texture of the internal surface of the pipe remains consistent even after many years of service.
Easy Maintenance
Because of the superior durability of ductile iron pipes, the maintenance required is negligible. In the event of a leak, inexpensive pipe sleeves can be used as a form of repair, eliminating the need for complete pipe replacement.
Sustainability
Last but not least, ductile iron pipes are environmentally friendly and recyclable. They can be produced from iron salvaged from recycled steel scraps, demolished buildings, or other sources.
Type of Ductile Iron Pipes
Ductile iron pipe for water supply
Primarily used for water supply, gas, and oil transportation in municipalities, industrial and mining enterprises, it is the preferred choice for water supply pipes, offering a high cost-effectiveness. It features lightweight, thin walls, and excellent resistance to pressure, impact, corrosion, and earthquakes. Its pipe joints utilize flexible connectors, and they offer a certain degree of elongation and deflection.
Ductile Iron Pipe for Drainage
This type of pipe utilizes rubber seals and bolt fastenings. It exhibits excellent flexibility and elasticity under internal water pressure, accommodating large axial displacements and lateral deflections. It is suitable for indoor drainage pipes in high-rise buildings, especially in seismic areas.
Ductile iron pipes for gas supply
It requires high airtightness and is suitable for the transportation of pressurized fluids such as gas.
Applications of Ductile Iron Pipes
Water Distribution
One of the most common uses of ductile iron pipe is for water distribution systems. This is due to its high resistance to corrosion, which is essential for delivering clean drinking water. Ductile iron pipe is also known for its strength and durability, making it a reliable choice for underground water mains and fire hydrant systems.
Sewer and Wastewater Applications
Ductile iron pipe is also used extensively for sewer and wastewater applications. Its high strength and toughness make it ideal for handling the stresses and strains associated with underground sewer systems. Ductile iron pipe is also highly resistant to corrosion and chemical attack, making it an ideal material for handling wastewater and other corrosive substances.
Gas Distribution
Ductile iron pipe is also commonly used for gas distribution systems. Its high strength and durability make it a safe and reliable choice for transporting natural gas and other gases over long distances. Ductile iron pipe is also highly resistant to corrosion, making it ideal for use in harsh environments where other materials may fail.
Industrial Applications
Ductile iron pipe is also used extensively in industrial applications. Its strength, toughness, and resistance to corrosion and chemical attack make it ideal for use in pipelines for a variety of chemicals and other industrial substances. Ductile iron pipe is also used for the transportation of slurries and other abrasive materials.
Irrigation
Ductile iron pipe is widely used for irrigation systems due to its durability and resistance to corrosion. Irrigation systems typically involve long stretches of underground piping, and ductile iron pipe's toughness and strength make it a reliable choice for this application.
Mining and Construction
Ductile iron pipe is used extensively in the mining and construction industries for a variety of applications. Its high strength and durability make it ideal for use in underground mining operations and for transporting materials in construction projects.
Fire Protection
Ductile iron pipe is also used for fire protection systems due to its strength and durability. Fire hydrant systems and underground fire mains require pipes that can withstand the high pressures and stresses associated with firefighting operations, and ductile iron pipe is an ideal choice for this application.
Performance of Ductile Iron Pipes
Mechanical Properties
After annealing, the microstructure is ferrite with a small amount of pearlite. The minimum tensile strength reaches 420 MPa, the yield strength is 300 MPa, and the elongation is ≥7%, approaching the performance of carbon steel.
Corrosion Resistance
The inner wall is sprayed with zinc or lined with cement mortar, and the outer wall is coated with anti-corrosion coatings such as asphalt paint and epoxy resin. It is suitable for conveying corrosive media such as gas and sewage.
Toughness
The spherical graphite reduces stress concentration, making the pipe resistant to impact and seismic events, and adaptable to geological deformation.
Production Process of Ductile Iron Pipes
Raw Materials
Molten iron of grade 18 or higher, with the addition of a nodulizer (magnesium powder) and an inoculant (ferrosilicon).
Casting
The molten iron is rotated at high speed (approximately 1000-1500 rpm) in a centrifugal ductile iron casting machine. This centrifugal force forms a uniform tube wall, resulting in a dense, defect-free structure.
Post-treatment
Annealing to eliminate internal stresses, zinc spraying for corrosion protection, interior lining with cement mortar or epoxy resin, and exterior coating with asphalt paint or polyurethane.
Ductile Iron Pipe Installation
Identify The Mounting Surface
According to the design, identify the mounting surface with the observer and level gauge. Make the bottom of ditch neat and avoid placing the pipe on the convex surface of the stones at the bottom.
Lay The Pipe
The flow direction is closely related to that of the socket. Normally, the water flows from socket to spigot. When slope is steep, put the socket upwards and install the pipe from down to up. When place the pipe in the ditch, avoid strong collision with bottom and wall.
Socket Cleanup
Carefully clean the socket inside, especially the position of rubber sealing ring. Do not leave residue such as paint, soil, sand and so on.
Spigot Cleanup
Clean the spigot and make the edges smooth by using lubricant.
Draw Standard Line
Installed line is usually marked in the spigot position of the company's products. During the construction, for the cut pipe, draw the standard line on the arch with a caliper. The distance between the line and the smooth edge should be 5mm - 10mm shorter than the socket depth.
Put the rubber seal ring into the socket and check whether it is a complete match. And then use special lubricant (other lubricant, engine oil, paint not allowed). Despite of the small-diameter pipe, no other position of the rubber seal ring needs lubrication.
Joint
For pipes of different sizes, use different tools to joint up them. See figure. Carefully insert a pipe gradually until the standard line meets the socket's front. If the resistance is too strong during pipe inserting, you should immediately stop and pull out the pipe. After checking the rubber seal ring and socket location, identifying the cause and solving it properly, you can re-insert the pipe. Next, insert the metal ruler into the annular space between the socket and the wall until it hits the rubber seal ring. The pipes connected to each other should has a same axis center, otherwise you should adjust the uneven part probably at the ditch bottom.
Check
After joint, check the rubber seal ring with a thick ruler along the entire arched line, in case of leak, which will damage the sealability.
Ditches Burial
Use soil free of sand, grass, roots and debris to bury and ensure the depth at least 200mm higher than the up-line. Soil on both sides of the pipe should be compacted, the upper part of which should be buried compacted for another 200mm - 300mm.
FAQ
We're professional ductile iron piping manufacturers and suppliers in China, specialized in providing high quality custom service. We warmly welcome you to buy high-grade ductile iron piping at competitive price from our factory.
