Solutions Engine

Coating Damage and Disbondment

Coating damage and disbondment can cause external corrosion, but when combined with other factors, such as high stress, soil conditions can lead to environmentally assisted damage, including stress corrosion cracking (SCC). This being so, it’s important to create an integrity management plan that includes steps for identifying disbonded or damaged coating before it creates a risk.

In the Gas Transmission market, TDW offers a suite of solutions to:

  • Clean lines prior to inline inspection to ensure the best possible run conditions.
  • Detect disbonded or damaged coating, as well as areas of corrosion.
  • Assess damage levels to help prioritize repairs.
  • Keep lines running safely and efficiently, in compliance with company and regulatory standards.



If coating disbondment or damage leads to corrosion or cracking, pigging can help facilitate repairs by cleaning the line prior to an isolation operation. Pigging removes built-up liquids, contaminants, and deposits on the pipe wall, to help ensure first-time success and a flawless isolation. This translates into a quicker turnaround and less downtime for Gas Transmission operators. 

  • VANTAGE® V cleaning pig – Multi-use pig designed to remove both hard, crust-like and soft, gummy deposits, as well as ferrous materials.
  • WCK cleaning pig – Removes contaminants and deposits that increase resistance to flow.
  • REDSKIN™ foam pig – Used for light cleaning; one version incorporates a urethane cleaning wrap with bypass groove that effectively removes paraffin and other soft deposits that could lead to corrosion.
  • UNISPHERE™ pig – Provides heavy-duty removal of liquid hydrocarbons and water from pipelines and piping systems.

Technical assistance is available from TDW subject matter experts for special circumstances or if the path to a solution requires consultation.


Through advanced inline inspection (ILI) technology to detect and characterize coating disbondment and damage with a high degree of accuracy, TDW helps Gas Transmission operators avoid multiple inspection runs and unnecessary excavations, saving time while lowering operational risks and costs.

  • SpirALL® Electromagnetic Acoustic Transducer (EMAT) – Using a unique sensor/magnetizer configuration, guided ultrasonic (sound) waves are transmitted into the pipe wall through direct contact, allowing EMAT to inspect natural gas and liquids pipelines. Coating disbondment and damage, which can be related to external metal loss and stress corrosion cracking (SCC), is detected with EMAT by making use of the attenuation measurements collected by the tool. The attenuation data is directly proportional to the types of coating or coating quality on the pipeline. If there is an area where coating has become disbonded or damaged, EMAT can detect this through the localized changes in attenuation.
  • Multiple Dataset (MDS) platform – Combines multiple technologies to generate comprehensive, critical information in a single tool run. MDS correlates damage related to coating disbond with EMAT by utilizing SpirALL magnetic flux leakage (SMFL), high field axial MFL, and low field axial MFL to detect areas of external metal loss and SCC. 
  • XYZ mapping (XYZ) – Supplies highly accurate location information about coating damage and disbondment by pairing global positioning system (GPS) coordinates with inertial mapping.