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Weld Flaw Acceptance Criteria for New Pipelines

Webinars 21 June 2022

Structural Integrity Technical Group Meeting: Weld Flaw Acceptance Criteria for New Pipelines 

Attendees will learn about the implementation of fracture mechanics methods, (Engineering Critical Assessment = ECA), to derive flaw acceptance criteria for pipeline girth welds. In particular, overviews of the main standards applied for this purpose will be discussed, e.g. CSA Z662, API 1104 and DNV-OS-F101/RP-F108. Challenges introduced with the use of ECA will be discussed and the event will be rounded off with presentations on fatigue assessment for offshore risers and future challenges for the use of ECA on pipelines.

This webinar is aimed at materials, welding and NDT engineers, fracture mechanics specialists, pipeline engineers and all others who are interested in pipeline integrity, especially those involved in pipeline construction whether it is onshore or offshore.

Experts from industry and TWI will be presenting on a range of topics:

Practical Implementation of ECA Based Weld Flaw Acceptance Criteria in Canada, David Horsley, Consultant, Horsley Consulting Ltd.

API 1104 Appendix A – Past, Present and Future, Dr Robin Gordon, Senior VP, Microalloying International

DNV’s Recommended Approach for Assessing Flaws in Pipeline and Riser Girth Welds – DNV-RP-F108, Steinar Bjerke, Principal Specialist, DNV

Challenges Implementing ECA Based Flaw Acceptance Criteria, David Reeves, Senior Engineer Materials and Welding, Nova People AG

Quantifying Probability of Fatigue Failure in Offshore Risers; an Alternative to the Use of Design Fatigue Factors (DFF), Dr Isabel Hadley, Technology Fellow, TWI Ltd
Presentation co-authored by: Alexandre Galiani Garmbis (Petrobras), Justin Crapps (ExxonMobil)

ECAs. The Future?, Dr Andrew Cosham, Consultant, Ninth Planet Engineering Limited


Download Programme


  • Professional Members of The Welding Institute: £25 + VAT (£30)
  • Industrial Members of TWI: £25 + VAT (£30)
  • Non-members: £95 + VAT (£114)
  • Retired Members: £25 + VAT (£30)
  • Students: £25 + VAT (£30)
  • TWI Training School Customers: £70 + VAT (£84)
  • TWI Staff - please contact Becki Parratt if you wish to register

Please note that payment must be made before the event in order to receive the joining instructions for the event.


If you can't join us on the day, you can still access the recording of the webinar and the presentations by registering ahead of the event.*

*presentation dissemination is dependent on presenter consent.


Registering on this Technical Group webinar as a non-member or a TWI Training Customer gives you full Associate Membership (AWeldI) for one year. To activate your membership, just complete the highlighted fields on the event registration form.

You will also benefit from:


The Welding Institute awards points towards CPD for delegates attending this webinar. Every hour attendance of an event will earn 2 points towards your continuing professional development.

Please contact if you require a certificate of attendance towards your continuing professional development.


Dr Isabel Hadley CEng, Eur Ing, FWeldI - Technology Fellow – Materials and Structural Integrity Technology Group, TWI

Dr Isabel Hadley CEng, Eur Ing, FWeldI

Technology Fellow – Materials and Structural Integrity Technology Group, TWI

Isabel is a Technology Fellow, recently semi-retired from TWI. Her work focuses on the development of analytical flaw assessment techniques, and their application to safety-critical welded structures and pressure equipment. She has a particular involvement in the development and validation of structural integrity procedures and standards such as:

  • BS 7910 (UK flaw assessment procedure); Chair of the committee, 2008-2021
  • R6 (UK nuclear assessment procedure); member of the panel
  • FITNET (European fitness-for-service procedure); co-author.

She is also Royal Academy of Engineering Visiting Professor in Integrity Management at the University of Bristol, as part of an initiative to transfer industrial know-how to engineering undergraduates.

Dr Andrew Cosham - Consultant

Dr Andrew Cosham

Ninth Planet Engineering

Dr Andrew Cosham is an independent consultant. He has worked in the oil and gas industry for over twenty five years. Andrew was previously employed by Atkins, Penspen/Andrew Palmer and Associates, and the Research & Technology Division of (the then) British Gas. Andrew is a Chartered Engineer and a Fellow of the Institution of Mechanical Engineers. Andrew is a member of two BSI technical committees: PSE/17/2 - Transmission pipelines and WEE/37 - Acceptance levels for flaws in welds.


Eur Ing David Reeves CEng, BSc, MSc, Sen MWeldI, IWE - Senior Engineer Materials and Welding

Eur Ing David Reeves CEng, BSc, MSc, Sen MWeldI, IWE

Senior Engineer Materials and Welding
Nova People AG

David Reeves is the Chair of the Structural Integrity Technical Group. David has over 30 years’ experience working in onshore and offshore construction, heavy engineering, and nuclear industries. He started his career with Whessoe Heavy Engineering Ltd in 1976 as a technical apprentice, progressing to Senior Welding Engineer for Onshore Construction in 1985. Since 1991 David has worked in Offshore Oil and Gas occupying a variety of roles for installation contractors, engineering companies and operators.

In all these roles, he has been active in developing weld flaw acceptance criteria for pipelines and steel catenary risers using his knowledge of welding, NDT and engineering critical assessment. He is currently working for Nord Stream2 AG as a senior materials, welding and NDT engineer.

Dr Robin Gordon - Senior Vice President

Dr Robin Gordon

Senior Vice President
Microalloying International

Dr Robin Gordon has consulted for the Oil and Gas Industry for more than 40 years and is a recognized expert in Engineering Critical Assessment (ECA) and Fracture & Fatigue Design.  Dr. Gordon has authored more than 100 papers on the development and application of Fitness-for-Service and Reliability design and assessment methods to offshore structures, pipelines and pressure vessels.  He has managed a number of major research projects on pipeline reliability as well as several international Joint Industry Projects on Fracture and Fatigue Design.  Dr Gordon is currently involved in a number of research initiatives to develop ECA methods for pipelines that experience large strains during installation or operation and pipelines that operate in sour service. 


David Horsley - Consultant

David Horsley

Horsley Consulting Ltd

David Horsley has over 30 years experience in the pipeline industry, specializing on materials, welding, and fracture.  Much of his time was spent on technology development and implementation.  He was chairman of the PRCI Design, Materials and Construction committee for six years, and led the Fracture focus of that committee for many more years.   He has served on the CSA pipeline Materials and Design standards committees.  David is the author or co-author of over one hundred papers or articles pertaining to pipeline materials, welding, ECA and design.

For more information please email: