RESEARCH REPORT 430

1 HSE. Health & Safety Executive Offshore gas turbines (and major driven equipment) integrity and inspection guidance notes Prepared by ESR Technology Ltd for the Health and Safety Executive 2006. RESEARCH REPORT 430. HSE. Health & Safety Executive Offshore gas turbines (and major driven equipment) integrity and inspection guidance notes Martin Wall, Richard Lee & Simon Frost ESR Technology Ltd Harwell International Business Centre Harwell Oxfordshire OX11 0QJ. Gas turbines are widely used offshore for a variety of purposes including power generation, compression, pumping and water injection. Relatively little information is included in safety cases, for example only the manufacture, model, power rating (MW), fuel types, and installation drawings showing the location of the turbines.

2 Some descriptive text may be included on the power generation package, back-up generators and arrangements for power transmission to satellite platforms. Information on integrity management and maintenance is limited or at a high level. This Inspection Guidance Note provides a more detailed assessment of gas turbines (GTs) and major driven equipment installed on UK offshore installations, focussing on integrity and maintenance issues. This complements the advice in HSE Guidance Note PM84, recently re-issued, covering control of risks for gas turbines used in power generation and HSE RESEARCH REPORT RR076 which provides general guidance on rotating equipment including turbines.

3 The applications, systems and components of offshore gas turbines are reviewed. Guidance is given on the integrity issues and maintenance typical for different systems. Summaries are given of database information on the turbines installed on UK installations together with recent incident and accident data. Recent experience and anecdotal information from operators is also reviewed. The inspection guidance note is principally designed to provide information for HSE inspectors in safety assessments, incident investigations and prior to site visits. The note may also be of interest to manufacturers, suppliers and operators of gas turbines (GTs) used offshore.

4 This REPORT and the work it describes was co-funded by the Health and Safety Executive (HSE) and the EU's Fifth Framework Programme of RESEARCH . Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy. HSE BOOKS. Crown copyright 2006. First published 2006. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording or otherwise) without the prior written permission of the copyright owner. Applications for reproduction should be made in writing to: Licensing Division, Her Majesty's Stationery Office, St Clements House, 2-16 Colegate, Norwich NR3 1BQ.

5 Or by e-mail to ii Acknowledgements The authors would like to thank the HSE inspectors, turbine suppliers, operators and others who have contributed to this REPORT and allowed pictures and other information to be reproduced. In particular we would like to thank the following HSE staff for their contribution: Prem Dua the project technical officer, Jim MacFarlane for advice on rotating equipment issues, Tom Gudgin for his valuable comments on electrical issues and control systems, Stan Cutts for advice in the context of the KP3 initiative, Danny Shuter for handling project issues and HSE inspectors who attended project seminars at Aberdeen, Bootle, Norwich and London for their comments.

6 Rainer Kurz from Solar is thanked specifically for allowing us to use some of the images and introductory information from his IGTI 2004 paper. This project was initiated by the HSE. RESEARCH Strategy Unit. The authors of HSE RESEARCH REPORT RR076 on rotating equipment are thanked for providing a starting point for present project. iii iv Foreword This REPORT covers the inspection and integrity of gas turbines (GTs) and major driven equipment (compressors, pumps, alternators). The focus is on offshore applications including floating installations and FPSOs. The work is directly relevant to HSE's Key Programme 3. (KP3) initiative. The REPORT is intended principally as an information source for HSE inspectors in safety assessments, incident investigations and prior to site visits.

7 The note may also be of interest to manufacturers, suppliers and operators of gas turbines (GTs) used offshore. The areas covered include: what can go wrong, typical inspection and maintenance, what is done differently offshore, relevant, codes and standards, hazards and safety concerns, good and best practice, summary of incident and accident data (RIDDOR, DO), a review of the main systems and components and how they work. A summary is given of advice in other HSE. documents including PM84 and RR076. Specific areas covered include: the basics of gas turbines, applications offshore, packaging concepts, electrical and control systems, major driven equipment, GTs on UK installations, safety codes and regulations (including environmental), hazards and failure modes, maintenance and inspection, operational issues and recent trends.

8 Section 1 provides an introduction and advice on use of the information in the REPORT Section 2 gives an introduction to gas turbines, the types of gas turbines that are used offshore, packaging concepts and their applications. Section 3 summarises the main applications offshore Section 4 describes offshore turbine packages in more detail Section 5 summarises the integrity, safety and maintenance issues for major driven equipment building on the information in RR076. Section 6 addresses the associated electrical systems. Section 7 focuses on control systems a main safety consideration and recent developments including synchronisation and corrected parameter control Section 8 summarises the turbines installed in the UK sector.

9 Section 9 covers safety cases, codes and regulations. Section 10 looks at degradation and failure modes including an analysis of incident, accident dangerous occurrence and reliability data. Summary tables are given by system and component. Section 11 looks at maintenance and inspection practice in-service and at overhaul. Section 12 looks at operational issues including hazards , start-up and shutdown, surge prevention, risk assessment and hazard management. Section 13 reviews recent trends in gas turbines including dry low emissions (DLE), micro- turbines, waste heat recovery systems and combine cycle gas turbines. Section 14 gives operational support guidance based on the principles developed in RR076.

10 Section 15 gives examples of good and best practice with applicable guidance and regulations and references listed in Sections 16 and 17 respectively. Supplementary information is included in a number of Appendices. Appendix 1 gives a current list of UK installations and Appendix 2 describes what would be included in a typical procurement package technical specification for gas turbines for a UK offshore installation. Appendix 3 reproduces HSE guidance note PM84 on gas turbines, Appendix 4 summarises the main turbine suppliers for UK installations derived from an analysis of DTI emissions data and other sources. The specifications for gas turbines used in the UK sector are summarised in Appendix 5.