Ductile Iron Pipe Repair: Operations & Maintenance

The maintenance of ductile iron pipes is a critical step. If any type of damage occurs, several steps must be taken to repair the damage or failure. The most common causes of failure are corrosion, joint leaks, and structural damage. However, some helpful repair techniques exist, such as pipe relining, spot repairs, and joint sealing solutions. Some materials are more suitable for use in each repair method. An expert opinion will help you choose the right material. Failure and damage can also be prevented by taking steps such as regular inspections, corrosion control, and following industry standards. However, the right DI repair service supplier must be decided for the best results.

What Are the Common Causes of Ductile Iron Pipe Failures?

Ductile iron pipes can face failure in different project situations. There are some common reasons for this failure. A few safety practices must be done in the installation, inspection, and maintenance stages. Any issues that are found must be taken care of as soon as possible in the ductile iron pipe repair process.

Corrosion

Ductile iron pipes are considered corrosion-resistant pipes. However, these pipes can face corrosion in two forms in a harsh environment. Referring to Science Direct, corrosion influences ductile iron and cast iron differently, but it can still be a threat to ductile iron pipes.

Internal corrosion: There are several reasons for internal corrosion. The major ones are certain chemicals and aggressive substances. The fluid in the pipes causes corrosion of pipe walls. This can eventually lead to leaks or complete failure of the pipes.
External corrosion: Another reason for the need for ductile iron pipe fitting repair is external corrosion. The main factors are the surrounding soil condition, the presence of corrosive elements, and stray electrical currents.

Joint Leaks

Joint sealing techniques are one of the most essential factors to consider when installing ductile iron pipes. With proper joint sealing techniques, the need for ductile iron pipe repair will decrease significantly. Joint leaks will occur due to two main reasons.

Joint material deterioration: Some components of the joints, such as seals or gaskets, will degrade over time. The degradation of these parts will lead to leaks or joint failures.
Improper joint installation: Improper joint installation significantly increases the risk of failure and leaks. In this case, ductile iron pipe repair is urgently needed.

Structural Damage

Structural damages are one of the most crucial issues ductile iron pipes can have. These damages directly threaten the pipes’ reliability. There are many reasons for structural damage; however, here are the most important ones. Each of these issues will make the pipes require serious repair.

Manufacturing defects: Some ductile iron pipes have serious defects during the manufacturing process. These defects end up creating weak points in the pipes, and the pipes will eventually face failure.
Excessive external loads: A primary form of structural damage is caused by external loads. Soil loads, heavy traffic, and ground movement are of these excessive loads. There is a need for ductile iron pipe repair to prevent cracks, collapse, and deformations.
Improper handling or installation: Improper handling, such as dropping or rough handling, threatens the integrity of the pipes.

Effective Techniques to Repair Ductile Iron Pipes

There are a few effective techniques for ductile iron pipe repair. These are some common ways for pipe rehabilitation. Depending on the pipe condition, each of these methods can be employed to repair the pipes. Also, expert consulting is very helpful in most cases.

Pipe Relining

Several pipe relining methods are available for ductile iron pipe repair. These methods are widely employed in projects that face pipe failure. Different liners are used in this technique to repair the pipes effectively.

Spiral-wound liners: These types of liners are made of interlocking PVC and HDPE strips. Being locked together, they form a continuous line. The liner is formed within the pipe that needs repair.
Fold-and-form liners: As the name reveals, these liners are folded to a smaller size. This allows them to be inserted into the damaged pipe. After being inserted, they expand and create a new pipe in the existing old pipe.
Cured-in-place pipe (CIPP) lining: These liners are made of flexible material, such as fiberglass or felt. They are inserted into the old pipe. To repair the ductile iron pipe, they cure it in place with heat, steam, or UV light. A new, seamless pipe is created within the old one, which seals leaks.

Spot Repairs

Another popular technique in many industries is spot repair. This type of ductile iron repair can be done to cure the pipes using two different methods. The right method is decided based on the project’s needs.

Grouting: In this specific method, cementitious or chemical grout gets injected into the exact damaged area of the pipe. The grout fills the cracks or voids that have led to damage. This type of repair offers additional structural support and seals leaks.
Internal point repair systems: Some damages are small cracks or isolated corrosion. Short liner sections are inserted into specific areas of the pipe to address the localized issue within the ductile iron pipe.

Joint Sealing Solutions

Joint sealing methods are known and popular solutions for ductile iron pipe repair. Two effective methods are commonly used, and you can see them below.

Internal joint seals: A certain type of seal is used to position within the joint so that any risk of leak or infiltration is prevented.
Chemical grout injection: Grout is injected into the specific area of the joint to fill voids and create a watertight seal.

What Are the Best Materials for Repairing a Ductile Iron Pipe?

Several different materials are used to repair a ductile iron pipe. However, the best material to repair these pipes effectively must be chosen. The decision on this material highly depends on an expert opinion and the damaged pipe condition. Also, the chosen repair technique determines the material. Here are the most common materials used in various ductile iron pipe repair techniques.

Cured-in-place pipe (CIPP) lining: Flexible materials like felt or fiberglass are saturated with epoxy or polyester resin. Vinyl ester resin is also used to saturate these liners. UV-cured liners are normally used for smaller-diameter pipes.
Fold-and-form liners: There are HDPE or PVC materials that are widely used for such liners.
Spiral-wound liners: This type of liner is different, as a specific type of strip is used. An interlocking strip of PVC or HDPE must be used to form spiral wound lines.
Grouting materials: Cementitious grouts are a useful type of material for ductile iron pipe repair. The only tip is that the used material must be Portland cement-based. Other chemical grouts, such as polyurethane or acrylic resin, are also used for grout. These materials grant structural support, leak sealing, and void filling.
Joint seals: Internal joint seals are performed by using rubber or elastomeric materials. Materials such as nitrile rubber or EPDM are mainly used in this method.
Mechanical repairs: Some replacement pipes are provided for this technique. These pipes can be made of ductile iron, HDPE, PVC, or other standard materials suitable for this usage. However, this technique is employed for specific requirements.

How to Maintain Ductile Iron Pipes and Prevent Failures?

Preventing damage to ductile iron pipes to perfectly maintain these pipes is a step before ductile iron pipe repair. According to Mcwane Ductile, failure prevention offers several advantages, such as saving time and money on projects. Also, the chances of crucial structural damage are significantly reduced.

Regular Inspections

Regular and routine inspections must be done for any visual damage or issue. Any sign of leak, corrosion, or structural damage must be taken seriously. Other advanced inspection methods, such as ultrasonic testing or closed-circuit television, can be used to control the condition of internal areas of the pipes.

Corrosion Control

Water quality highly influences the internal condition of the pipes. Bad water will cause internal corrosion, so water quality must be monitored regularly. Some effective corrosion control measures must be used, such as cathodic protection systems or protective coatings and linings.

Follow Industry Standards and Best Practices

Manufacturers develop critical recommendations. Following these recommendations, along with industry standards, will greatly reduce the chances of failure, leaks, or other structural damages. These standards and recommendations cover installation, maintenance, and repair processes. Also, consulting with professional engineers will be highly helpful.

How to Choose the Best DI Repair Service Supplier?

There are a few key factors to consider when choosing the best DI repair service supplier. The supplier’s reputation is a crucial factor. Also, their experience in ductile iron pipe repair is highly determinant. All required warranties and guarantees must be given to the customer. The quality of materials and equipment is crucially important in choosing the best supplier. Lastly, good customer service is a must in this case.

Conclusion

Although preventing damage must be the first priority in projects, proper repair steps can be taken if necessary. If ductile iron pipes face any type of structural damage, a few effective repair techniques can be implemented. The repairing process must be done carefully and precisely. For that reason, a good and expert ductile iron pipe repair service supplier must be chosen.