pipeline construction challenges
TRANSCRIPT
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Pipeline Construction Pipeline Construction ChallengesChallenges
NAPCA WorkshopAugust 19, 2010 Houston, Texas
Kenneth Y. Lee
Office of Pipeline Safety
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
PHMSA MissionPHMSA Mission
• To ensure the operation of the Nation’s pipeline transportation system is:
– Safe
– Reliable
– Environmentally sound
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Incidents (2002Incidents (2002--2009)2009)
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Incidents (2002Incidents (2002--2009)2009)
0
5
10
15
20
25
30
Excavation Corrosion Misc & Other Equipment Construction W & OF Materials Operations
%
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
IncidentsIncidents
• 2007
• Natural Gas
• Excavation
• 1 fatality
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
IncidentsIncidents
• 2007
• Natural Gas
• 30-inch
• Corrosion
• 1 fatality
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
IncidentsIncidents• 2007
• Natural Gas
• 30-inch
• Selective Seam Corrosion
• High Resistivity Soils
• No injuries
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
IncidentsIncidents• 2007
• 12 inch HVL
• LF-ERW Seam
• 2 fatalities
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
IncidentsIncidents
• 2008
• Natural Gas
• 30-inch
• Excavation
• 5 injuries
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
New Construction Issues Observed by New Construction Issues Observed by PHMSA InspectorsPHMSA Inspectors
0
20
40
60
80
100
120
Coating Welding Excavation NDT Pipe Steel Bending Lowering
Occ
ure
nce
s
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Observed Coating Observed Coating IssuesIssues
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Backfill before Coating has CuredBackfill before Coating has Cured
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Patch Stick: Inadequate AdhesionPatch Stick: Inadequate Adhesion
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Coating Over TapeCoating Over Tape
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Coating DisbondmentCoating Disbondment
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Backfill DamageBackfill Damage
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Coating Over Dirt/DebrisCoating Over Dirt/Debris
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Welding Band DamageWelding Band Damage
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Pipe Quality IssuesPipe Quality Issues• Low strength X70 & X80
• Inconsistent chemical and mechanical properties
• Poor mill rolling practices
• Advisory Bulletin (PHMSA 2009-1048)
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Girth Weld FailuresGirth Weld Failures
Radiographic Weld Inspection Hydrostatic Testing
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Hydrogen Cracking Hydrogen Cracking
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Hydrogen Hydrogen CrackingCracking
HYDROGEN
MICRO-STRUCTURE TENSILE
STRESS
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Hydrogen Cracking Risk by Electrode Hydrogen Cracking Risk by Electrode TypeType
E9010E8010E7010E6010FCAW (flux-cored)E9018E8018E7018GMAW (MIG)
Increasing Risk
LowHydrogen
Cellulosic
U.S. Department of TransportationPipeline 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 TransportationPipeline and Hazardous Materials Safety Administration
Hydrogen CrackingHydrogen Cracking
• Thru-thickness Repair
• Partial-thickness Repair
• Transitions
• Tie-ins 6:006010
9010
9018-M
Full thickness repair of mechanized weld
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Partial Thickness Repair:Partial Thickness Repair:Only 1 Cellulosic Weld PassOnly 1 Cellulosic Weld Pass
9010
9018-M
Mechanized GMAW
Low Hydrogen
WeldMetal
9018-M
6:00
Repair
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Partial Thickness Repair:Partial Thickness Repair:Cellulosic & Low HydrogenCellulosic & Low Hydrogen
Repair
6010
9010
9018-M
MechanizedGMAW
12:00
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
SelfSelf--shielded Fluxshielded Flux--Cored TransitionCored Transition
81T8 (FCAW-S) Fill & Cap
9018-M Hot 6010 Root
6010 Backweld
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Weld PreheatWeld 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 TransportationPipeline and Hazardous Materials Safety Administration
Girth Weld IssuesGirth Weld Issues• Transitions• Misalignment • Cut Induction Bends
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Improper Weld TransitionsImproper Weld Transitions
ASME B31.8 Fig. I-5
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
MisalignmentMisalignment
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
MisalignmentMisalignment
Alignment – Does this meet API 1104?
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Bends & FittingsBends & Fittings
• If cutting bends, use segmentable bends with tighter body tolerance
• Ends should meet:
– API 5L dimensional limits
– API 1104 fit-up requirements
Tangent End
Tangent End
EndTolerance
Hot induction bend cross-section
Bend fittingsHot induction bends
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Weld Misalignment at Cut BendWeld Misalignment at Cut Bend
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Best Practice:Best Practice:Shop fabricated bend assemblyShop fabricated bend assembly
Field weld
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Lowering In StressLowering In Stress• Maximum weld stress occurs during lowering in
• Most weld failures at top & bottom of pipe
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Industry ActionsIndustry 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 TransportationPipeline and Hazardous Materials Safety Administration
API 5LAPI 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)
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
API 1104 Appendix AAPI 1104 Appendix A• Guidance for ECA & lowering-in stresses
• Retests for Charpys & crossweld tensiles
• Consideration for weld misalignment
• Weld Procedure Essential Variable. A change in the:
– Steel mill (slab, ingot, etc.)
– Rolling mill (plate, coil)
– Pipe mill (manufacturing facility)
– Pipe manufacturing process (UOE, spiral, ERW, etc.)
– Chemical composition limits (Pcm, CE, C)
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
API 1104 Repair Task GroupAPI 1104 Repair Task Group
• Backweld, multiple, & double repairs
• Repair length (minimum & maximum)
• Hardness testing
• NDT delay
• Preheat & Postheat
• Procedure qualification
• Welder qualification
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
API 5L/1104 Joint Task GroupAPI 5L/1104 Joint Task Group
• Misalignment & dimensional tolerances
• Tensile test orientation
• Residual magnetism
• Identification of steel/rolling mill
• Multiple grades & strength limits
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Recent PHMSA ActionsRecent PHMSA Actions
April 2009: PHMSA New Construction Workshop
May 2009: ADB: Potential Low & Variable Yield & Tensile Strength & Chemical Composition Properties inHigh Strength Line Pipe
June 2009: PHMSA Letter to Industry Trade Associations
Summer 2009: Letters to Alt MAOP SP holders on Low Strength Pipe
Spring/Fall 2009: Worked with operators to identify and remove low strength pipe
August 2009: Construction web site established
March 2010: ADB: Girth Weld Quality Issues Due to Improper Transitioning, Misalignment, and Welding Practices of Large Diameter Line Pipe
April 2010: Distribution Construction Workshop
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Looking AheadLooking Ahead
• Continued focus on construction inspections
• Expect increased enforcement actions on construction issues – for 72%SMYS and 80%SMYS pipelines
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Pipeline Construction WebpagePipeline Construction Webpagehttp://primis.phmsa.dot.gov/construction/index.htmhttp://primis.phmsa.dot.gov/construction/index.htm
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
PHMSA PHMSA –– Links Links
• Pipeline Safety Guidance – Advisory Bulletins, Low Strength Pipe Guidelines, MAOP Rule FAQs
– http://www.phmsa.dot.gov/pipeline/guidance
• Construction Issues
– http://primis.phmsa.dot.gov/construction/index.htm
• MAOP Rule – FAQs
– http://primis.phmsa.dot.gov/maop/index.htm
• Special Permits – FAQs
– http://primis.phmsa.dot.gov/classloc/faqs.htm
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
Thank you
Kenneth Y. LeeOffice: (202) 366-2694
E-mail: [email protected]
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
QUESTIONSQUESTIONS
U.S. Department of TransportationPipeline and Hazardous Materials Safety Administration
PHMSAPHMSAOffice of Pipeline Safety Office of Pipeline Safety