685 INTEGRATED INSPECTION AND ANALYTICAL TECHNOLOGIES FOR BURIED PIPE ASSESSMENTS Stephen F. Biagiotti, Jr. P.E. and Andy Crompton Structural Integrity Associates, Inc 10731 E. Easter Ave, Suite 100 Centennial, CO 80112, USA Roger Royer Structural Integrity Associates, Inc 301 Science Park Rd., Suite 121 State College, PA 16803, USA ABSTRACT The demand for inspection services as part of a site’s management of buried and underground pipe and tank programs has been increasing over the last several years in support of NEI Initiative 09-14 – Guideline for the Management of Underground Piping and Tank Integrity. Unlike traditional NDE methods that utilize direct contact with a material surface for inspection, buried pipe inspections utilize “Indirect Inspection” methodologies to gain insight into the condition of the pipe without the need for excavation. Once adverse signatures are observed, excavation and quantitative examinations using traditional NDE methods are used. A secondary benefit of this approach is that the disposition of large amounts of pipe with minimal likelihood for significant degradation can be established, saving the site valuable time and resources while maintaining the reasonable assurance of an asset’s integrity for safe operation. This approach optimizes inspection planning at locations with the greatest potential for worst- case external corrosion degradation. This paper will present two methods, APEC and GWT, and the data integration and analysis processes used to arrive at prioritized recommendations regarding a pipe’s condition. An example will be used to demonstrate how the data supports corrosion engineering decisions used to establish the reasonable assurance of buried pipe integrity. INTRODUCTION NEI’s NSIAC has identified five actions along with implementation dates as a method to establish reasonable assurance of structural integrity for the Underground Piping and Tanks Initiative (UPTI). The use of indirect inspections is a foundational element in any UPTI program. Indirect Inspections are intended to be used as a part of the Risk Ranking and Prioritization phase of an effective aging management program [1]. Indirect Inspections provide observable data associated with the likelihood of external degradation, and when used in conjunction with other risk ranking parameters, provide targeted information useful for Direct Examination planning. Focusing resources toward locations/areas at which corrosion activity may have occurred or may be occurring has proven effective in other industries to demonstrate the reasonable assurance of pipe integrity. The continued use of Indirect Inspection tools can also be a leading indicator of system changes, further increasing the confidence in the system performance. Direct Examinations follow Indirect Inspections and provide the actual “inspection” of the buried systems or piping. Direct Examination is the combined process of excavation to expose the pipe and the characterization of a pipe condition through approved NDE technologies. The quantitative, measured results obtained from a Direct Examination can be used to support continued operability decisions.
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685
INTEGRATED INSPECTION AND ANALYTICAL TECHNOLOGIES FOR BURIED PIPE
ASSESSMENTS
Stephen F. Biagiotti, Jr. P.E. and Andy Crompton
Structural Integrity Associates, Inc
10731 E. Easter Ave, Suite 100
Centennial, CO 80112, USA
Roger Royer
Structural Integrity Associates, Inc
301 Science Park Rd., Suite 121
State College, PA 16803, USA
ABSTRACT
The demand for inspection services as part of a site’s management of buried and underground pipe and
tank programs has been increasing over the last several years in support of NEI Initiative 09-14 –
Guideline for the Management of Underground Piping and Tank Integrity. Unlike traditional NDE
methods that utilize direct contact with a material surface for inspection, buried pipe inspections utilize
“Indirect Inspection” methodologies to gain insight into the condition of the pipe without the need for
excavation. Once adverse signatures are observed, excavation and quantitative examinations using
traditional NDE methods are used. A secondary benefit of this approach is that the disposition of large
amounts of pipe with minimal likelihood for significant degradation can be established, saving the site
valuable time and resources while maintaining the reasonable assurance of an asset’s integrity for safe
operation. This approach optimizes inspection planning at locations with the greatest potential for worst-
case external corrosion degradation. This paper will present two methods, APEC and GWT, and the data
integration and analysis processes used to arrive at prioritized recommendations regarding a pipe’s
condition. An example will be used to demonstrate how the data supports corrosion engineering decisions
used to establish the reasonable assurance of buried pipe integrity.
INTRODUCTION
NEI’s NSIAC has identified five actions along with implementation dates as a method to establish
reasonable assurance of structural integrity for the Underground Piping and Tanks Initiative (UPTI). The
use of indirect inspections is a foundational element in any UPTI program.
Indirect Inspections are intended to be used as a part of the Risk Ranking and Prioritization phase
of an effective aging management program [1]. Indirect Inspections provide observable data associated
with the likelihood of external degradation, and when used in conjunction with other risk ranking
parameters, provide targeted information useful for Direct Examination planning. Focusing resources
toward locations/areas at which corrosion activity may have occurred or may be occurring has proven
effective in other industries to demonstrate the reasonable assurance of pipe integrity. The continued use
of Indirect Inspection tools can also be a leading indicator of system changes, further increasing the
confidence in the system performance.
Direct Examinations follow Indirect Inspections and provide the actual “inspection” of the buried
systems or piping. Direct Examination is the combined process of excavation to expose the pipe and the
characterization of a pipe condition through approved NDE technologies. The quantitative, measured
results obtained from a Direct Examination can be used to support continued operability decisions.
686
INDIRECT INSPECTION METHODS
The nuclear industry is not the first to embark on the widespread evaluation of in-service buried pipe for
the purposes of determining the integrity and continued fitness for purpose. At the turn of the 21st century,
the U.S. transmission pipeline industry experienced several incidents that resulted in fatalities and
significant property damage. In response, the U.S. Congress passed the Pipeline Safety Improvement Act
of 2002 [2] whereby pipeline operators were required to risk rank and perform baseline inspections to
demonstrate the pipelines were safe for continued operation. The approved inspection technologies were
initially: internal inline inspection (ILI) UT or other technologies capable of reporting metal loss,
deformation or cracking; hydrostatic testing; or excavation and conventional NDE methods.
Construction practices for natural gas pipeline, unlike hazardous liquid pipelines, included pipe
configurations that prevented the use of the highly reliable and cost effective ILI technologies. These
restrictions included: 90° fittings, pipe diameter changes, size-on-size tees, sub-size valves and lack of
access for the insertion of ILI tools. In response, the regulators introduced new terminology into the
regulations [3] based on research completed at the Gas Research Institute (GRI) demonstrating the value
and effectiveness of a new approach coined “Direct Assessment” [4]. Direct Assessment (DA) is a four-
step continuous improvement process in which: (1) a Pre-Assessment is performed to gather information
about a large collection of assets, establish risk ranking and grouping of similar assets, and select indirect