U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Pipeline Construction Pipeline Construction Challenges Challenges NAPCA Workshop August 19, 2010 Houston, Texas Kenneth Y. Lee Office of Pipeline Safety
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration PHMSA Mission PHMSA Mission • To ensure the operation of the Nation’s pipeline transportation system is: – Safe – Reliable – Environmentally sound
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Incidents (2002 Incidents (2002-2009) 2009)
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Incidents (2002 Incidents (2002-2009) 2009) 30 25 20 15 % 10 5 0 Excavation Corrosion Misc & Other Equipment Construction W & OF Materials Operations
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Incidents Incidents • 2007 • Natural Gas • Excavation • 1 fatality
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Incidents Incidents • 2007 • Natural Gas • 30-inch • Corrosion • 1 fatality
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Incidents Incidents • 2007 • Natural Gas • 30-inch • Selective Seam Corrosion • High Resistivity Soils • No injuries
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Incidents Incidents • 2007 • 12 inch HVL • LF-ERW Seam • 2 fatalities
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Incidents Incidents • 2008 • Natural Gas • 30-inch • Excavation • 5 injuries
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration New Construction Issues Observed by New Construction Issues Observed by PHMSA Inspectors PHMSA Inspectors 120 100 80 Occurences 60 40 20 0 Coating Welding Excavation NDT Pipe Steel Bending Lowering
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Observed Coating Observed Coating Issues Issues
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Backfill before Coating has Cured Backfill before Coating has Cured
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Patch Stick: Inadequate Adhesion Patch Stick: Inadequate Adhesion
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Coating Over Tape Coating Over Tape
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Coating Disbondment Coating Disbondment
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Backfill Damage Backfill Damage
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Coating Over Dirt/Debris Coating Over Dirt/Debris
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Welding Band Damage Welding Band Damage
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Pipe Quality Issues Pipe Quality Issues • Low strength X70 & X80 • Inconsistent chemical and mechanical properties • Poor mill rolling practices • Advisory Bulletin (PHMSA 2009-1048)
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Girth Weld Failures Girth Weld Failures Radiographic Weld Inspection Hydrostatic Testing
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Hydrogen Cracking Hydrogen Cracking
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Hydrogen Hydrogen Cracking Cracking HYDROGEN MICRO- TENSILE STRUCTURE STRESS
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Hydrogen Cracking Risk by Electrode Hydrogen Cracking Risk by Electrode Type Type E9010 E8010 Cellulosic E7010 E6010 Increasing FCAW (flux-cored) Risk E9018 E8018 Low Hydrogen E7018 GMAW (MIG)
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Susceptible Microstructure (Hardness) Susceptible Microstructure (Hardness) • Historically, values > 350 HV should be evaluated for the risk of hydrogen assisted cracking • Cracking observed at 200 to 260 HV
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Hydrogen Cracking Hydrogen Cracking • Thru-thickness Repair • Partial-thickness 9018-M Repair • Transitions 9010 • Tie-ins 6010 6:00 Full thickness repair of mechanized weld
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Partial Thickness Repair: Partial Thickness Repair: Only 1 Cellulosic Weld Pass Only 1 Cellulosic Weld Pass 9018-M 9018-M Repair Low 9010 Hydrogen Weld Metal Mechanized GMAW 6:00
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Partial Thickness Repair: Partial Thickness Repair: Cellulosic & Low Hydrogen Cellulosic & Low Hydrogen 9018-M Repair 9010 6010 Mechanized GMAW 12:00
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Self Self-shielded Flux shielded Flux-Cored Transition Cored Transition 81T8 (FCAW-S) Fill & Cap 9018-M Hot 6010 Root 6010 Backweld
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Weld Preheat Weld Preheat • Heat entire circumference, especially 12:00 & 6:00 locations • Measure temperature immediately before start of every weld pass using: – Temperature Indicating Crayons – Contact Pyrometer – Infrared Thermometer (reading depends on surface condition and distance)
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Girth Weld Issues Girth Weld Issues • Transitions • Misalignment • Cut Induction Bends
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Improper Weld Transitions Improper Weld Transitions ASME B31.8 Fig. I-5
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Misalignment Misalignment
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Misalignment Misalignment Alignment – Does this meet API 1104?
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Bends & Fittings Bends & Fittings End Bend fittings Tolerance Tangent End Hot induction bends • If cutting bends, use segmentable bends with tighter body tolerance • Ends should meet: – API 5L dimensional limits – API 1104 fit-up Tangent End requirements Hot induction bend cross-section
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Weld Misalignment at Cut Bend Weld Misalignment at Cut Bend
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Best Practice: Best Practice: Shop fabricated bend assembly Shop fabricated bend assembly Field weld
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Lowering In Stress Lowering In Stress • Maximum weld stress occurs during lowering in • Most weld failures at top & bottom of pipe
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Industry Actions Industry Actions • Workshops • Pipe Quality Work Groups (8 work groups) • Construction Work Groups (5 work groups) • Standards updates PHMSA is appreciative of industry efforts
U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration API 5L API 5L • Proposed changes to reduce potential for non-conforming pipe • Quality management system (QMS) for steel mill & rolling mill • Tensile test & bracket retest locations in coil/plate • Traceability of pipe to coil/plate • Enhanced Manufacturing Procedure Specification (MPS) – Applies to steel mill, rolling mill, & pipe mill • Enhanced Manufacturing Procedure Qualification Test (MPQT) – Test of initial production to qualify MPS. Includes assessment of coil/plate tensile property variability and coil/plate to pipe strength changes • New - Inspection and Test Plan (ITP)
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