The Engineer’s Guide to Pipe Defects Repairable by Engineered Composite Wraps (ISO 24817 / ASME PCC-2)

‍

Composite wrap technology has become an essential tool for asset integrity management in industries ranging from oil and gas to water, power, and heavy industry. Engineered composite repair systems, when designed and installed in accordance with ISO 24817 and ASME PCC-2, offer a safe, compliant, and cost-effective alternative to traditional steel replacement.

One of the most common questions asset owners ask is: “What types of defects can composite wraps actually repair?”

The short answer is: quite a lot.

Composite wraps are engineered to restore structural integrity and pressure-containing capabilities across a wide range of pipe and tank damage scenarios. Below, we break down the key defect types where composites provide proven, long-term solutions.

‍

1. External Corrosion

‍

What it is:

‍
External corrosion is the gradual loss of pipe wall thickness caused by exposure to moisture, oxygen, and corrosive environments. It often occurs on uninsulated lines exposed to weather, buried pipelines in contact with soil, or sections where coating systems have failed.

‍

‍

How composite wraps help:

• Composite wraps bridge across the corroded section and redistribute hoop and axial stresses away from the damaged wall.
• The repair restores pressure-containing capability without the need for hot work.
• The composite encapsulation prevents further external corrosion by sealing the substrate from oxygen and electrolytes.
• Repairs can be designed for anything from minor pitting to extensive corrosion zones, extending the service life of the asset by up to 20 years.

‍

Typical applications:

• Above-ground process piping.
• Storage tank nozzles.
• Buried pipelines after excavation

‍

2. Corrosion Under Insulation (CUI)

‍

What it is:

‍
CUI is one of the most costly integrity challenges in the industry. Moisture penetrates insulation systems and becomes trapped against the pipe wall, leading to accelerated corrosion hidden from visual inspection. By the time CUI is discovered, significant wall loss may already exist.

‍

‍

How composite wraps help:

• After removing insulation, composite systems encapsulate the damaged zone, sealing it off from future moisture ingress.
• The repair restores hoops strength and protects against further external corrosion.
• Composite wraps are low profile, allowing insulation to be re-applied back over the top.
• Importantly, composite wraps avoid the downtime and expense of cutting out and replacing the section.

Typical applications:

• Fuel lines at coastal or marine terminals.
• Steam and condensate lines in refineries.
• Cryogenic service lines where insulation is unavoidable.

‍

3. Internal Corrosion

‍

What it is:

‍
Internal corrosion is driven by the process fluid itself. CO₂, H₂S, chlorides, produced water, or aggressive chemicals in transport lines can attack the pipe wall from the inside, leading to thinning or pitting.

‍

‍

How composite wraps help:

• Composite repairs are installed externally but restore hoop strength to compensate for the lost wall thickness caused by internal corrosion.
• Where corrosion has penetrated through the wall, a leak sealing method (such as a high-strength epoxy sealant) is first applied to re-establish the pressure boundary before wrapping.
• Important limitation: Unlike external corrosion, internal corrosion will continue to grow underneath the composite wrap. This means:
  
  • If wall loss rates are unknown, repairs can typically only be designed for a maximum of 2 years' design life.
  • If wall loss rates are known from inspection and monitoring, the repair can be engineered to account for the predicted defect size at the end of the composite wrap's design life.

Typical applications:

• Offshore production lines.
• Sour gas service pipelines.
• Produced water injection lines.

‍

4. Mechanical Damage (Dents and Gouges)

‍

What it is:

‍
Pipes and tanks can be dented or gouged by external impacts — dropped tools, strikes, or accidental contact with heavy equipment. Even if the wall hasn’t corroded, dents and gouges create stress concentrations that reduce fatigue life and may cause premature failure.

‍

‍

How composite wraps help:

• Composite repairs smooth out the geometry, redistributing stresses around the damaged zone.
• They prevent crack initiation at stress risers, extending the life of the asset.
• For deeper gouges, epoxy filler materials are used to rebuild the pipe profile prior to wrapping.

Typical applications:

• Subsea pipelines struck by anchors.
• Road crossings and yard pipelines.
• Above-ground storage tank skirts.
• Loading/unloading terminals with high vehicle traffic.

‍

5. Leaking Defects (Type B Repairs)

‍

What it is:

‍
Leaks may result from corrosion, pinholes, or stress cracking. In traditional scenarios, this would mean shutting down the line, cutting out the damaged section, and welding in a replacement.

‍

‍

How composite wraps help:

• Type B composite repairs, as defined in ISO 24817 and ASME PCC-2, allow for the sealing of live leaks
• A leak-sealing compound or injection system is used first to stop the leak and re-establish the pressure boundary. The composite wrap is then applied to provide structural reinforcement.
• This enables safe repair without shutdown in many cases, saving operators significant downtime and costs.

Typical applications:

• Fuel  transfer lines
• Water  injection lines.
• Tank  penetrations and nozzles

‍

6. Weld Defects

‍

What it is:

‍
Weld defects such as porosity, undercutting, or cracking can create weak points in pressure systems. Over time, cyclic stresses can exacerbate the problem.

‍

‍

How composite wraps help:

• Composite wraps provide a non-intrusive reinforcement around defective welds.
• They redistribute stresses and reduce the risk of further propagation.
• This is especially valuable where re-welding is impractical or where hot work poses safety risks.
 

Typical applications:

• Girth welds on pipelines.
• Tank seam welds.
• Nozzle welds in refineries and chemical plants.

‍

7. Cracks

‍

What it is:

‍
Cracks may form due to fatigue, thermal cycling, or stress corrosion. They are serious threats to asset integrity and must be addressed carefully.

‍

‍

How composite wraps help:

• Important note: Composite wraps do not themselves arrest crack growth. The crack must be stopped and stabilised before composite installation.
• Once the defect is controlled, the composite wrap provides reinforcement and redistributes stresses, preventing the crack from being re-activated under service loads.

Typical applications:

• Pipelines operating in high-stress environments.
• Ammonia and fertilizer plants (where SCC is prevalent).
• High-temperature lines subject to thermal cycling.

‍

8. Erosion and Abrasion

‍

What it is:

‍
High-velocity fluids, entrained solids, or turbulent flow can erode the internal wall of pipes and bends. External abrasion can occur where pipes rub against supports or saddles.

‍

‍

How composite wraps help:

• Internal erosion damage cannot usually be rebuilt directly with fillers, but external wraps restore strength and compensate for the lost wall thickness.
• At pipe supports or saddles, wraps act as a protective barrier against further abrasion.
• In erosive services, composites can be combined with external abrasion-resistant coatings for added durability.

Typical applications:

• Slurry pipelines in mining.
• Elbows and bends in water injection lines.
• Pipe supports in refineries.

‍

Why Composite Repairs Are Effective Across So Many Defects

The versatility of composite wraps comes down to three factors:

1. Stress  Redistribution – The wrap takes load off the damaged steel, ensuring the defect is no longer the limiting factor.
2. Barrier Protection – The resin matrix seals the surface and prevents oxygen and electrolytes from causing further external corrosion.
3. Custom Engineering – Each repair is designed for the specific defect geometry, operating pressure, and temperature, in full compliance with ISO 24817 and ASME PCC-2.

By combining these elements, composites can address everything from minor surface corrosion to active leaks.

‍

Conclusion

Composite wrap repair systems are not a one-size-fits-all solution. Instead, they are carefully engineered to restore integrity across a wide range of defect types — external corrosion, CUI, internal corrosion,dents and gouges, leaks, weld defects, cracks, and erosion.

For asset owners, the benefits are clear:

• Compliance with international standards.
• Minimal downtime compared to cut-and-replace.
• Long-term service life extension (often 20 years or more).
• Cost savings and improved safety.

As infrastructure around the world continues to age, the role of composite wraps will only grow. They provide operators with a reliable way to extend the life of critical assets while maintaining safety and compliance.

Ready to extend the life of your pipelines or tanks?

‍
At Icarus Composites, we design and deliver composite wrap repair systems fully compliant with ISO 24817 & ASME PCC-2. Whether you’re dealing with external corrosion, CUI, internal wall loss, or leaks, our engineered solutions restore integrity and extend service life safely and cost-effectively.

‍

Contact us today to discuss your repair requirements by clicking here.

‍