Pipeline Repair Methods, Hot Tapping, and In-Service Welding

It will be necessary to bring a laptop to this course.

The objective of this course is to provide an in-depth overview of the various aspects of pipeline repair and modification (full-encirclement sleeves, hot taps, etc.) as well as to address the concerns for welding onto in-service pipelines. A thorough understanding of the factors that affect the concerns for welding onto in-service pipelines will allow repairs and modifications to be made with confidence. The proper use of in-service welding allows both economic and environmental benefits to be realized by avoiding pipeline shutdown and interruption of service. The course is intended for a wide range of personnel – from engineers and managers to welders and inspectors.

COURSE OBJECTIVES

The course will dispel a number of misconceptions that have developed pertaining to operating practices required to safely weld onto an in-service pipeline. If the knowledge gained can be used to justify the application of in-service welding where it would have otherwise been prohibited (or prevent a single failure), the first application of the results can often offset the cost of attendance by orders of magnitude. The application of industry best practices for pipeline repair, hot tapping, and in-service welding will ensure the safety of workers, reduce the probability of a failure, and can help to extend the life of pipeline systems.

CONTINUING EDUCATION UNITS

Upon completion of the course, participants will be awarded 1.4 CEUs.

WHO SHOULD ATTEND

Pipeline engineers, Operations and Maintenance personnel, inspectors, and welders.

INSTRUCTORS

Bill Bruce, P.E., IWE, CWEng, is Senior Principal Consultant, Welding Technology, with DNV in Columbus, Ohio. Prior to this he was a technology leader at the Edison Welding Institute and a senior engineer at Panhandle Eastern Pipeline Company. He is a member of the American Petroleum Institute API 1104 Committee and is the chairman of the Maintenance Welding Subcommittee.

Dr. Chris Alexander is President of ADV Integrity, Inc. He has been integrally involved in assessing the effects of dents and mechanical damage on the structural integrity of pipelines. He has also been involved in assessing the use of composites in repairing pipelines and offshore risers.

SYLLABUS

DAY 1

Pipeline Repair Methods/Hot Tapping/InService Welding

• Introduction
• Incentives
• Primary concerns

Defect Assessment Prior to Repair

• Reason for assessment
• Types of pipeline defects
• Pressure reduction requirements
• Corrosion measurement methods
• Corrosion assessment methods
• Assessment of grinding defects

Welding Processes/Discontinuities and Defects

• Arc welding processes
• Consumable designations
• Crack types and discontinuities vs. defects

Burnthrough and Related Safety Concerns

• Factors affecting burnthrough
• Effect of wall thickness
• Effect of welding parameters
• Effect of flow rate/pressure
• Avoiding burnthrough
• Related concerns

Hydrogen Cracking Concerns

• Recent significant incidents
• Common factor/recommendation
• Hydrogen cracking requirements
• Weld hydrogen levels
• Crack susceptible weld microstructures
• Welding residual stresses
• Welding metallurgy for carbon steels
• Thermal cycles of welded joints
• Prevention of hydrogen cracking

FullEncirclement Repair Sleeves

• Full encirclement sleeve types
• Principal of operation
• Assuring effective reinforcement
• Sleeve design
• Sleeve fabrication
• Other Sleeve Types

Hot Tap Branch Connections

• Branch connection design
• Reinforcement types
• Integrally reinforced
• Line replacement/stopping
• Pressure testing
• Hot tapping through welds

Pipeline Repair by Weld Deposition

• Physical concept
• History of weld deposition repair
• Burnthrough risk
• Integrity restoration
• Practical application
• External repair of internal wall loss
• Regulatory activities

DAY 2

NonWelded Repairs and Commercial Repair Products

• Repair by grinding
• Bolton repair clamps
• Fiberreinforced composite repairs
• Epoxyfilled shells
• Grouted tees
• Steel sleeves vs. composite repairs

Selecting an Appropriate Repair Method

• Pipeline repair manual
• Detailed selection criteria
• Repair option summary
• Qualifying factors

Code and Regulatory Requirements

• Procedure and Welder Qualification
• History of API 1107/API 1104 Appendix B
• Qualification of Procedures
• InService Welder Qualification
• Comparison with other codes (CSA Z662, AS28852, etc.)

Procedure Development and Selection for Hot Tap and Repair Sleeve Welding

• Procedure options
• History of weld cooling rate prediction
• Predictive methods
• HAZ hardness limits
• Iterative procedure qualification trials
• Procedure selection guidelines

Practical Aspects of Hot Tap and Repair Sleeve Welding

• Practical aspects of avoiding burnthrough
• Practical aspects of avoiding hydrogen cracking
• Welding procedure selection examples
• Chemical composition determination
• Proper electrode handling
• Proper fitup and welding sequence
• Control of heat input levels
• Inspection and testing

Alternative Welding Processes for InService Welding

• Conventional processes
• Alternative processes
• Branch connection root pass welding
• Cellulosiccoated electrode limitations

A Simple Approach to Hot Tap and Repair Sleeve Welding

• Introduction
• Five general rules of thumb
• Prove it yourself

Lessons to be Learned from Past Pipeline Repair/Hot Tapping Incidents

• Reported incidents
• Previously unreported incidents
• Ten commandments of inservice welding