Global pipeline solutions provider T.D. Williamson (TDW) received a patent for its Positive Material Identification (PMI) process from the U.S. Patent Office.
The PMI process, patent number US 9,880,056, uses a variety of non-destructive tools and techniques to generate traceable, verifiable and complete pipe records for in-situ pipe material verification, providing trusted results along with considerable cost, time and efficiency benefits.
TDW began developing the PMI process in 2011, soon after the Pipeline and Hazardous Materials Safety Administration (PHMSA) issued an initial Advisory Bulletin (ADB-11-01) establishing maximum allowable operating pressure (MAOP) or maximum operating pressure (MOP) using record evidence and integrity management risk identification, assessment, prevention and mitigation.
PHMSA noted that incomplete or partial records are not an adequate basis for establishing MAOP or MOP and indicated that, in the absence of complete, verified records, operators may need to conduct in-situ examination, pressure testing, nondestructive testing or other activities to very verify the characteristics of the pipeline when identifying and assessing threats or risks. PHMSA also eliminated a grandfather clause that allowed gas transmission operators to rely on historical data for establishing the MAOP of pipe installed before 1970.
According to Jeff Wilson, TDW Vice President, Global Solutions Engineering, the company's PMI process helps pipeline operators comply with PHMSA's multi-disciplinary approach to verify that steel gas transmission pipelines are adequate for continued operation.
"In essence, the patented process provides pipeline operators with a proven approach to determine pipe material properties in-situ and without the need to destructively test pipeline samples," Wilson said.
Using the PMI process avoids system shutdown, decreasing pressure and destructive techniques such as cutting out a coupon test specimen, which had previously been the only alternative. The efficacy of this approach has been validated externally, including by industry-leading, third-party laboratories, as well as pipeline operator blind tests and other industry organizations