Pipeline Deformation


Excessive geometric deformation of the pipe can result in ovality, dents, wrinkles, etc., that can affect the structural integrity of the pipeline.

Through a wide range of products and services (some requiring the pipeline to be piggable), TDW can help Gas Distribution operators detect and verify pipeline deformation, assess line integrity, and help execute remedial measures or repairs.



Cleaning pipelines with pigs prior to running inline inspection (ILI) tools helps Gas Distribution operators improve data capture about potential threats to pipeline integrity, including deformation, and leads to more accurate information about necessary repairs.

In addition, TDW gauging pigs are used to identify deformation by measuring the internal diameter of pipelines, detecting bore restrictions and obstructions, and proving roundness. These pigs are equipped with aluminum gauging plates – available in a variety of thicknesses and diameters – that are designed to deform locally when they reach an obstruction. This prevents additional pipe damage and, except in the case of severe obstructions, keeps the pig from getting stuck in the pipeline.

Pigs for pre-ILI cleaning:

  • VANTAGE® V cleaning pig – Remove both hard, crust-like and soft, gummy deposits, as well as ferrous materials.
  • PitBoss™ cleaning pig – Removes soft to medium-hard deposits from internal pits, which is essential to improving the effectiveness of corrosion inhibitors.
  • WCK cleaning pig – Removes contaminants and deposits that increase resistance to flow in smaller pipelines.
  • 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.
  • Pencil brush pig – Rids pipelines of finely divided black powder that has accumulated as the result of corrosion on steel pipe walls as well as hard scale deposits

Pigs for gauging deformation:

  • OptionALL™ SO-G gauging pig – Designed for pipelines from 4 inches through 14 inches; available with multiple gauge plates, providing complete information in a single run.
  • VANTAGE® LV-G – For pipelines 16 inches and larger; combines the strength and durability of the steel-bodied VANTAGE V steel cleaning pig with proven aluminum gauging discs from TDW.
  • Polly-G REDSKIN™ pig – Available in medium- and high-density foam with aluminum gauging plate bolted on.
  • X-Pig® multi-purpose utility tool – A versatile, one-piece tool molded from TDW proprietary Formula SI™ urethane, available with optional bolted-on gauging plate.

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


Sensitive, accurate, and verifiable, high-resolution inline inspection (ILI) technology from TDW detects and locates pipeline anomalies, including pipe wall deformations. Whether needing to inspect new construction or existing pipelines, TDW will help Gas Distribution operators comply with regulatory requirements, prioritize repairs, and ensure system integrity while avoiding multiple inspection runs and unnecessary excavations.

ILI for deformation detection:

  • KALIPER® 360 (K360) technology Engineered to provide deformation detection in newly constructed and in-service pipelines up to 48 inches in diameter.
  • Deformation (DEF) technology – High resolution tool efficiently detects dents and other minute bore reductions, with accuracy to calculate dent strain and prioritize plain dents.
  • Magnetic flux leakage (MFL) – High resolution technology optimized for liquids pipelines detects and sizes volumetric corrosion features such as metal loss in dents.
  • Gas magnetic flux leakage (GMFL) – High resolution technology optimized for natural gas pipelines detects and sizes volumetric corrosion features such as metal loss in dents.
  • Multiple Dataset (MDS) platform Combines multiple technologies to generate comprehensive, critical information in a single tool run. Utilizes all available technologies to detect and prioritize interactive threats associated with dents.
  • XYZ mapping (XYZ) – Supplies highly accurate location information about every defect reported by pairing global positioning system (GPS) coordinates with inertial mapping.


TDW provides non-destructive in-ditch assessment of pipeline deformation, from localized areas up to entire joint lengths. By incorporating the Gas Distribution operator’s interaction rules with the TDW mapping capabilities, TDW can provide critical and highly accurate information to help operators address pressing issues and prioritize remediation activities.

  • Digital pit depth gauge Measures external pipeline anomalies, including areas of external pitting and deformations.
  • Automated laser profilometry  Quickly and accurately determines corrosion depths on large external sections of pipeline and may also be used to evaluate deformations. Provides permanent documentation.


TDW offers Gas Distribution market owners and operators hot tapping and plugging (HT&P) solutions for a wide array of pipeline defects and maintenance challenges from dents to corrosion to valve failure. TDW equipment and services are engineered for safety and efficiency, allowing operators to better protect their employees and the surrounding community. 

The HT&P process incorporates a low 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. 

Whether operators are purchasing equipment to perform their own HT&P jobs or turn to TDW to execute the service for them, they can rely on the company’s broad line of equipment and consumables. TDW application engineers are recognized industry experts, ready to assist operators through each project phase – from start to finish. To meet regional needs quickly and efficiently, TDW maintains equipment and consumables in service centers around the globe. 

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 their pipelines — and restore product flow — in the shortest time possible.