Direct Assessment Philip Sher Connecticut Department of Public
Direct Assessment Philip Sher Connecticut Department of Public Utility Control Gas Pipeline Safety Unit Representing NAPSR National Association of Pipeline Safety Representatives November 4, 2003 1
NAPSR § NAPSR = National Association of Pipeline Safety Representatives § non-profit organization § state pipeline safety directors, managers, inspectors and technical personnel § to support, encourage, develop and enhance pipeline safety regulation § Founded on December 2, 1982 2
Integrity Management Program Pipeline IMP = “a plan or system” “to handle or direct with a degree of skill” the “soundness” of a pipeline system 3
We Need Integrity Management Bellingham, WA Carlsbad, NM Edison, NJ 4
We Will Have Integrity Management 5
Steps in Risk Management 6
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ANSI Gas Piping Technology Committee & ANSI B 31. 8 S Integrity Management Process. 10
High Consequence Area – The Real World 11
Integrity Assessment Methods 1. Smart pig 2. Pressure test 3. Direct assessment 4. Other (new technology) 12
Smart Pigs § 1 st smart pigs – mid 1960’s, primarily for the detection of wall thinning. Now other types of defects - cracks, coating disbondment, dents and gouges - are detectable § Smart pig digs have served to calibrate and validate smart pig results 13
Smart Pigs § Smart pigs need § launchers & receivers § long radius bends § full opening valves § constant pipe diameter § Smart pigs may require interruption § 25 -30% of transmission pipelines are piggable 14
Pressure Testing § Require taking pipeline out of service § Water removal can be difficult § Water can promote internal corrosion § Pressure testing can grow subcritical flaws into critical flaws § Pressure test provides limited information and limited evaluation of future performance 15
Direct Assessment § ECDA = External Corrosion Direct Assessment § ICDA = Internal Corrosion Direct Assessment § SCCDA= Stress Corrosion Cracking Direct Assessment 16
ECDA 4 Step Process § Step 1 - Pre Assessment § Step 2 - Indirect Examination § Step 3 - Direct Examination § Step 4 - Post Assessment 17
Direct Assessment § Absolute need for DA § MUST be perfected § Must define parameters where it works § Must define parameters to evaluate it in use § Must develop body of knowledge and talent to utilize DA 18
Tools of ECDA § Cathodic Protection Readings (CP) 19
Tools of ECDA § Close Interval Survey (CIS) 20
Tools of ECDA § Direct Current Voltage Gradient (DCVG) 21
Tools of ECDA § C-Scan (The C-Scan mode or pulse-echo provides a planar view image at a specific depth. Illustrations of delaminations and void formation can be generated. ) 22
Tools of ECDA § Current Mapper 23
Direct Assessment § Some DA tools are old and there is considerable experience § Some DA tools are new with little experience § The DA process is new incorporating old and new tools, old and new techniques, and significant new data integration and documentation 24
Direct Assessment § Just as smart pig needed calibration and verification, DA will also need to be proven for the many conditions that may exist. § DA must be repeatable § DA must have a high level of confidence § Operator must demonstrate compliance § Regulator must confirm compliance 25
Reassessment Period § Original proposed reassessment period § Final reassessment period? 26
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Ultimate Goal 28
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- Slides: 29