Solutions Engine

Stress Corrosion Cracking

When pipeline segments are subjected to higher levels of hoop stress, they can be more susceptible to stress corrosion cracking (SCC), particularly if they have sustained hydrostatic testing. In the Gas Transmission market, TDW offers a variety of technologies to detect, evaluate, and help mitigate SCC

TDW services enable operators to:

  • Detect microscopic cracks in the pipeline.
  • Assess susceptibility of SCC in various pipeline segments.
  • Prioritize repairs.
  • Avoid pipeline shutdown.
  • Isolate and repair the affected pipe segment without interruption to service.
  • Keep pipelines running safely and efficiently, in compliance with company, industry, and regulatory standards.



Through advanced inline inspection (ILI) technology to detect and characterize stress corrosion cracking (SCC), TDW helps Gas Transmission operators optimize the number of inspections and unnecessary excavations, saving time while lowering operational risks and costs.

  • Multiple Dataset (MDS) platform – Combines multiple technologies to generate comprehensive, critical information in a single tool run. The MDS tool can be leveraged in combination with the SpirALL® Electromagnetic Acoustic Transducer (EMAT) tool when there is presence of corrosion with the crack colonies. This is very typical of near-neutral PH SCC.
  • 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. SCC is detected with EMAT by correlating attenuation data for coating disbond with reflection data for crack colonies. This is an effective correlation because SCC (on pipelines) results from the combination of a stress concentration (crack growth) and corrosive environment (coating disbond).
  • XYZ mapping (XYZ) – Supplies highly accurate location information about bending strains and seam abnormalities reported by pairing global positioning system (GPS) coordinates with inertial mapping.


TDW provides the Gas Transmission market non-destructive in-ditch assessment to detect and size crack and crack-like anomalies in the pipe wall, including inside welds, near mechanical damage, and in high-stress areas.

  • Phased array – An advanced ultrasonic inspection used to detect and size planar anomalies, such as stress corrosion cracking, this evaluation allows for permanent documentation of acquired data for anomaly growth monitoring.
  • Conventional shear wave ultrasound – This technology detects and sizes planar anomalies that are perpendicular to the pipe wall.
  • Magnetic particle inspection (MPI) – A combination of magnetic flux leakage (MFL) testing and visual inspection, this evaluation checks exposed pipe for surface anomalies, such as stress corrosion cracking.


In the Gas Transmission market, where pipeline shutdown often is not an option, TDW offers safe and efficient hot tapping and plugging (HT&P) solutions for a wide array of pipeline defects and maintenance challenges, from dents to corrosion to valve failure.

The HT&P process incorporates a high pressure pipeline fitting, valve, tapping machine, and isolation equipment – all working together to provide a safe and proven isolation solution. Once the area of pipeline that needs work has been safely isolated and evacuated, the line modification can be performed.

TDW isolation technology plays a critical role in this process, and a temporary bypass allows work to be performed without the need to stop product flow. The TDW STOPPLE® Train isolation system, for example, uses double block and bleed technology to help increase efficiency and safety during pipeline modification. This approach to line isolation, which only requires a single pipeline tap, reduces costs associated with fittings, valves, welding and inspection services. The bleed port affixed on the line ensures that any product that bypasses the first seal is contained and evacuated through the bleed port, which helps operators better protect people and the environment.

Because double block and bleed plays such a large role in protecting people, the environment, and communities that a number of regulators in Canada now require it for HT&P repairs. American regulators are likewise moving in that direction.

Whether operators purchase equipment to perform their own HT&P jobs or turn to TDW to execute the service, they can rely on the company’s broad line of equipment and consumables. TDW engineers and manufactures nearly every component needed for an HT&P project, and the company’s tapping and plugging machines are considered the industry standard. To meet regional needs quickly and efficiently, TDW maintains equipment and consumables in service centers around the globe.

TDW can also partner with operators before the work begins, providing consulting services to help them make optimum use of TDW products and services. TDW application engineers are recognized industry experts, ready to assist operators through each project phase – from start to finish. 

TDW also offers RES-Q® Wrap and Steel Repair Sleeves, quick, simple solutions that allow operators to keep their pipeline operational and within code.

To prepare for future challenges, operators have the option of creating an Emergency Pipeline Repair System (EPRS), which equips them to take a proactive approach to pipeline emergencies. Working with the TDW team, operators will have the planning and resources in place to repair and recommission the pipelines — and restore product flow — in the shortest time possible.