First Edition 2011 Book ISBN: 978-1-85609-494-8 Ebook ISBN: 978-1-85609-495-5 Copyright of SIGTTO, Bermuda In conjunction with Oil Companies International Marine Forum, Bermuda British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library. Notice of Terms of Use The advice and information given in this Manifold Recommendations for Liquefied Gas Carriers (‘Guide’) is intended purely as guidance to be used at the user’s own risk. No warranties or representations are given nor is any duty of care or responsibility accepted by the Society of International Gas Tanker and Terminal Operators (SIGTTO) or Oil Companies International Marine Forum (OCIMF), their membership, employees, or any person, firm, corporation or organisation (who or which has been in any way concerned with the furnishing of information or data, the compilation or any translation, publishing, supply of the Guide) for the accuracy of any information or advice given in the Guide or any omission from the Guide or for any consequence whatsoever resulting directly or indirectly from compliance with, adoption of or reliance on guidance contained in the Guide even if caused by a failure to exercise reasonable care on the part of any of the aforementioned parties Cover images courtesy of Exmar and iStock Witherby Seamanship International is a division of Witherby Publishing Group Ltd Published by Witherby Publishing Group Ltd 4 Dunlop Square, Livingston, Edinburgh, EH54 8SB, Scotland, UK Tel: +44(0)1506 463 227 Fax: +44(0)1506 468 999 Email: info@emailws.com Web: www.witherbys.com Printed and bound in Great Britain by Bell & Bain Ltd, Glasgow W ITHERBY P U BLISHING GRO U PSince-1740 iii CONTENTS Definitions ..............................................................................................................................................................v 1. Purpose, Scope and Introduction .......................................................................................................................1 1.1 Purpose and Scope ...................................................................................................................................3 1.2 Introduction ..............................................................................................................................................3 2. Categories of Gas Carriers ...............................................................................................................................5 2.1 Categories of LPG Carriers ........................................................................................................................7 2.2 Categories of LNG Carriers .......................................................................................................................7 3. Cargo Manifold Position ....................................................................................................................................9 3.1 Conventional Construction .......................................................................................................................11 3.2 Spherical Construction LNG and LPG Carriers ..........................................................................................11 3.3 Manifold Arrangement ............................................................................................................................11 3.4 Presentation Flange Arrangement ...........................................................................................................15 3.5 Offshore Marine Loading Systems ............................................................................................................16 4. General Manifold Requirements ......................................................................................................................17 4.1 Manifold Material ...................................................................................................................................19 4.2 Presentation Flanges ...............................................................................................................................19 4.3 Manifold Strength ...................................................................................................................................19 4.4 Marking of Manifolds .............................................................................................................................20 4.5 Distance Pieces .......................................................................................................................................20 4.6 Reducers and Spool Pieces ......................................................................................................................20 4.7 Manifold Support ...................................................................................................................................21 5. Strainers on Gas Carriers ................................................................................................................................23 5.1 General .................................................................................................................................................25 5.2 Strainer Type and Disposition ..................................................................................................................25 5.3 Flow Characteristics ................................................................................................................................25 5.4 Fittings ..................................................................................................................................................26 5.5 Mesh Size ..............................................................................................................................................26 5.6 Strainer Inspection and Maintenance .......................................................................................................26 6. Protection from Cargo Spills ............................................................................................................................29 6.1 Manifold Deck Protection ........................................................................................................................31 6.2 Coaming Requirements ...........................................................................................................................31 6.3 Drainage ...............................................................................................................................................31 6.4 Water Curtains on LNG Vessels ...............................................................................................................31 6.5 Drip Trays ..............................................................................................................................................31 6.6 Fittings ...................................................................................................................................................31 7. Service Lines ...................................................................................................................................................33 7.1 Drinking Water Connection .....................................................................................................................35 8. Bunker Connections ........................................................................................................................................37 8.1 Number and Arrangement ......................................................................................................................39 8.2 Size and Spacing of Presentation Flanges .................................................................................................39 8.3 Strength .................................................................................................................................................39 iv 8.4 Reducers and Spool Pieces ......................................................................................................................40 8.5 Bunker Fuel Spill Containment .................................................................................................................40 8.6 Diesel/Gas Oil Fuel Manifolds.................................................................................................................40 8.7 Blank Flanges .........................................................................................................................................40 9. Manifold Area Lighting ...................................................................................................................................41 10. Lifting Equipment and Cargo Hose Support ......................................................................................................45 11. LPG Vessels Involved in Floating Hose Transfers ................................................................................................49 12. Safety Requirements .......................................................................................................................................53 12.1 Electrical Equipment ................................................................................................................................55 12.2 Fire-Fighting ...........................................................................................................................................55 12.3 Emergency Exits from the Manifold Area ..................................................................................................55 12.4 Personnel Access During Cargo Transfer ..................................................................................................55 12.5 Tripping Hazards ....................................................................................................................................55 12.6 Removal of Manifold Blank Covers ...........................................................................................................55 13. Reference Documents and Bibliography ...........................................................................................................57 Appendices ..........................................................................................................................................................61 v DEFINITIONS In these recommendations, the following definitions and abbreviations apply: ANSI 150/300 American National Standards Institute Specification B16.5, Class 150 and Class 300 (British Standards equivalent BS 1560:Section 3.1:1989 Class 150 and Class 300). B Bunkering connection. EN1474 Installation and Equipment for Liquefied Natural Gas - Design and Testing of Marine Transfer Systems. ESD Emergency shutdown. Hard (cargo) Arms Commonly known as marine loading arms. A rigid articulated pipe construction provided with swivel joints that allow the necessary movements of the construction. IGC Code ‘International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk’. IMO International Maritime Organization. L Liquefied gas connection. N Nitrogen connection. Presentation Flange The outboard flange of the reducer or spool piece, to which the loading transfer line is connected. Reducer or Spool Piece The reducer or spool piece fitted to the outboard flange of the distance piece. Distance Piece A short section of flanged pipe, fitted outboard of the manifold valve(s), secured to a deck mounted manifold support. Transfer Line Articulated piping or the transfer hose, and swivels if any, or a combination of the articulated piping and hose, allowing the transfer of liquefied gas between ship and terminal. V Vapour connection. All measurements are metric except for pipe and flange sizes, which are expressed in inches as at the time of publication this is general practice. PURPOSE, SCOPE AND INTRODUCTION 3 Purpose, Scope and Introduction 1. Purpose, Scope and Introduction 1.1 Purpose and Scope These recommendations have been developed to bring together, in one document, the manifold arrangements and strainer guidelines for LPG and LNG carriers, with the aim of promoting improved safety and efficiency in operations and to assist in planning the position of loading and discharging facilities in new jetties. The specifications have been reviewed by LNG and LPG ship operators, berth design specialists, naval architects, ship builders and equipment manufacturers. The recommendations are intended to serve as a guideline to owners and operators of liquefied gas vessels, ship builders and planners. The guidance is intended for new vessels and it is not implied that arrangements on existing vessels should be altered. 1.2 Introduction These recommendations represent a revision to earlier guidance published by OCIMF and SIGTTO entitled ‘Standardisation of Manifolds for Refrigerated Liquefied Gas Carriers for Cargoes from 0°C to Minus 104°C’, ‘Recommendations for Manifolds for Refrigerated Liquefied Gas Carriers (LNG)’ and ‘Recommendations for the Installation of Cargo Strainers on LNG Carriers, Second Edition October 1992’. The guidance reflects the demand for optimum spacing and heights brought about by the use of rigid cargo arms, or any type of transfer lines, particularly for refrigerated vessels, incorporating emergency shutdown systems to give spill and cargo arm protection. Owing to the nature of their construction, certain types and sizes of liquefied gas carriers may be unable to comply with all of the requirements of these recommendations. Where possible, the differences between ship design and these recommendations should be minimised. Notwithstanding the progress that has been made since 1979 to improve conformity in manifold arrangements, it is recognised that many existing ships and terminals are unable to follow these recommendations. Owners and operators of such ships and terminals should appreciate that this may lead to operational restrictions and they should be prepared to discuss these differences before a ship is programmed to any berth for the first time. It is not suggested or implied that ships constructed before publication of this document should be altered. Although ship to ship (STS) transfer operations are carried out on a regular basis with LPG, LNG STS is a relatively recent development. Considerations are made, within this document, to take into account the industry movement toward LNG STS and also to review past experience with LPG STS.