Session Details

History of In-line INSPECTION and Recent Technology Advancements

The session will address history and current practice of  inline pipeline inspection. The session will also provide a look ahead to future of inline pipeline inspections and how inline pipeline inspections can be further improved.



Starting in the early 1940s with the war emergency pipeline effort, cleaning tools known as pigs, were utilized to maintain cleanliness and throughput of product in the pipeline. In the 1950s and 1960s, there became a need to better assess the integrity of these ageing pipelines.

By 1965, the first in-line inspection (ILI) tool was created by Tuboscope to detect areas of metal loss on bottom of the pipeline. This device was called a magnetic flux leakage (MFL) tool. Soon after the invention of the MFL tool, T.D. Williamson (TDW) created the first deformation (DEF) tool, used to inspect the pipeline for dents and out-of-roundness pipe. By the late 1970s and through the 1980s, higher resolution MFL and DEF tools were developed by other vendors and the inspection business grew rapidly. Finally, the 1990s and into the 2000s brought on the invention of ultrasonic crack tools and combo-tools to meet the industry demand for detection and identification of new threat types that were previously undetectable. The multiple dataset (MDS) tool developed by TDW in 2008 has proven to be one of the most capable tools on the market to identify these new threat types that were previously unreported.

This presentation will provide a historical overview of ILI technology development and present more recent advancements in ILI industry that are allowing operators to become more proactive toward the assessment of various integrity threats. This advancement will be showcased through a couple case studies from MDS inspections.


Lloyd Pirtle, T.D. Williamson


Texas A & M University Graduate, BS – 1982 Sales, Sales Management, Operations Management, Market Dev. for Piping Systems operators and most recently Bus Dev for Integrity Services. Experience in Gathering, Water/Wastewater, Nuclear/Fossil Power, Chemical/Petrochemical, with a strong focus in Liquid/Gas Pipeline Transmission and Gas Distribution. Ten years – valve manufacturer. Twenty three years – TD Williamson including various capacities in technical support for products and services. The last 14 years supporting Pipeline Integrity Products & Services.