DEP 31.40.10.13-Gen.pdf

TECHNICAL SPECIFICATION DESIGN OF PIPELINE PIG TRAP SYSTEMS DEP 31.40.10.13-Gen. December 1998 DESIGN AND ENGINEERING PRACTICE This document is confidential. Neither the whole nor any part of this document may be disclosed to any third party without the prior written consent of Shell International Oil Products B.V. and Shell International Exploration and Production B.V., The Hague, The Netherlands. The copyright of this document is vested in these companies. All rights reserved. Neither the whole nor any part of this document may be reproduced, stored in any retrieval system or transmitted in any form or by any means (electronic, mechanical, reprographic, recording or otherwise) without the prior written consent of the copyright owners. PREFACE DEP (Design and Engineering Practice) publications reflect the views, at the time of publication, of: Shell International Oil Products B.V. (SIOP) and Shell International Exploration and Production B.V. (SIEP) and Shell International Chemicals B.V. (SIC) The Hague, The Netherlands, and other Service Companies. They are based on the experience acquired during their involvement with the design, construction, operation and maintenance of processing units and facilities, and they are supplemented with the experience of Group Operating companies. Where appropriate they are based on, or reference is made to, national and international standards and codes of practice. The objective is to set the recommended standard for good design and engineering practice applied by Group companies operating an oil refinery, gas handling installation, chemical plant, oil and gas production facility, or any other such facility, and thereby to achieve maximum technical and economic benefit from standardization. The information set forth in these publications is provided to users for their consideration and decision to implement. This is of particular importance where DEPs may not cover every requirement or diversity of condition at each locality. The system of DEPs is expected to be sufficiently flexible to allow individual operating companies to adapt the information set forth in DEPs to their own environment and requirements. When Contractors or Manufacturers/Suppliers use DEPs they shall be solely responsible for the quality of work and the attainment of the required design and engineering standards. In particular, for those requirements not specifically covered, the Principal will expect them to follow those design and engineering practices which will achieve the same level of integrity as reflected in the DEPs. If in doubt, the Contractor or Manufacturer/Supplier shall, without detracting from his own responsibility, consult the Principal or its technical advisor. The right to use DEPs is granted by SIOP, SIEP or SIC, in most cases under Service Agreements primarily with companies of the Royal Dutch/Shell Group and other companies receiving technical advice and services from SIOP, SIEP or SIC. Consequently, three categories of users of DEPs can be distinguished: 1)Operating companies having a Service Agreement with SIOP, SIEP, SIC or other Service Company. The use of DEPs by these Operating companies is subject in all respects to the terms and conditions of the relevant Service Agreement. 2)Other parties who are authorized to use DEPs subject to appropriate contractual arrangements. 3)Contractors/subcontractors and Manufacturers/Suppliers under a contract with users referred to under 1) or 2) which requires that tenders for projects, materials supplied or - generally - work performed on behalf of the said users comply with the relevant standards. Subject to any particular terms and conditions as may be set forth in specific agreements with users, SIOP, SIEP and SIC disclaim any liability of whatsoever nature for any damage (including injury or death) suffered by any company or person whomsoever as a result of or in connection with the use, application or implementation of any DEP, combination of DEPs or any part thereof. The benefit of this disclaimer shall inure in all respects to SIOP, SIEP, SIC and/or any company affiliated to these companies that may issue DEPs or require the use of DEPs. Without prejudice to any specific terms in respect of confidentiality under relevant contractual arrangements, DEPs shall not, without the prior written consent of SIOP and SIEP, be disclosed by users to any company or person whomsoever and the DEPs shall be used exclusively for the purpose for which they have been provided to the user. They shall be returned after use, including any copies which shall only be made by users with the express prior written consent of SIOP and SIEP. The copyright of DEPs vests in SIOP and SIEP. Users shall arrange for DEPs to be held in safe custody and SIOP or SIEP may at any time require information satisfactory to them in order to ascertain how users implement this requirement. All administrative queries should be directed to the DEP Administrator in SIOP. NOTE: In addition to DEP publications there are Standard Specifications and Draft DEPs for Development (DDDs). DDDs generally introduce new procedures or techniques that will probably need updating as further experience develops during their use. The above requirements for distribution and use of DEPs are also applicable to Standard Specifications and DDDs. Standard Specifications and DDDs will gradually be replaced by DEPs. DEP 31.40.10.13-Gen. December 1998 Page 2 TABLE OF CONTENTS 1.INTRODUCTION.4 1.1SCOPE 4 1.2DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS4 1.3DEFINITIONS 4 1.4ABBREVIATIONS6 1.5ACTION ITEMS. 6 1.6CROSS-REFERENCES6 2.TECHNICAL SPECIFICATION.7 2.1GENERAL 7 2.2BARREL. 8 2.3PIPEWORK. 11 2.4BRANCH CONNECTIONS13 2.5VALVES. 16 2.6END CLOSURES18 2.7SPECTACLE BLINDS.20 2.8BENDS 21 2.9PIG SIGNALLERS.22 2.10CATHODIC PROTECTION ISOLATION AND EARTHING CONNECTIONS 23 2.11SUPPORTS. 24 2.12PRESSURE INDICATORS25 2.13SPHERE LAUNCHING/RECEIVING PINS/FLAPPERS26 3.SERVICE CONDITIONS AND CODE REQUIREMENTS.27 3.1GENERAL 27 3.2DESIGN CODE27 3.3DESIGN FACTOR.28 3.4DESIGN PRESSURE28 3.5DESIGN TEMPERATURE.28 3.6DESIGN VELOCITIES.28 3.7TEST PRESSURE.28 3.8CORROSION ALLOWANCE.28 4.LAY-OUT AND ANCILLARYFACILITIES29 4.1GENERAL 29 4.2ONSHORE. 29 4.3OFFSHORE. 29 4.4HORIZONTAL PIG TRAPS.30 4.5VERTICAL PIG LAUNCHERS.30 4.6ACCESS PLATFORMS.30 5.DESIGN ASPECTS OF MATERIAL PROCUREMENT31 5.1GENERAL 31 5.2LOW TEMPERATURE SERVICE.31 5.3MATERIAL SPECIFICATIONS31 6.REFERENCES33 7.FIGURES. 35 APPENDICES APPENDIX 1VALVE TYPE SELECTION42 APPENDIX 2INTERLOCK SYSTEM LOGIC.43 DEP 31.40.10.13-Gen. December 1998 Page 3 1.INTRODUCTION 1.1SCOPE This DEP specifies requirements and gives recommendations for the design of pig trap systems for onshore and offshore pipelines having a diameter of 100 mm to 1 400 mm (4 to 56 inch). It is written in the context of liquid, gas and multi-phase hydrocarbon fluids, but may be applicable to other fluids. This DEP is a revision of the DEP of the same number dated December 1992. This revision incorporatesrequirementsforend-closurespreviouslyissuedseparatelyinDEP 31.40.21.32-Gen. “ Pig Trap End Closures” , issued in April 1993 (which is now withdrawn). The following components or topics are not covered by this DEP: -criteria for deciding whether pig traps are required; -subsea pig launchers and receivers; -pig launcher valves (i.e. valves where pigs can be loaded into the side of the valve). NOTE:Although this DEP excludes specific requirements for subsea pig traps, many aspects will still be relevant for such applications. This DEP is intended for design purposes only and not for material procurement. Design aspects relating to procurement are given in (5). The design could result in either the purchase of prefabricated traps or the purchase of individual components for field fabrication. 1.2DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS Unless otherwise authorised by SIOP and SIEP, the distribution of this DEP is confined to companies forming part of the Royal Dutch/Shell Group or managed by a Group company, and to Contractors and Manufacturers/Suppliers nominated by them (i.e. the distribution code is “F“ as described in DEP 00.00.05.05-Gen.). This DEP is intended for use when designing pipelines in oil refineries, gas handling installations, chemical plants, oil and gas production facilities, and supply/marketing installations. If national and/or local regulations exist in which some of the requirements may be more stringent than in this DEP the Contractor shall determine by careful scrutiny which of the requirements are the more stringent and which combination of requirements will be acceptable as regards safety, environmental, economic and legal aspects. In all cases the Contractor shall inform the Principal of any deviation from the requirements of this DEP which is considered to be necessary in order to comply with national and/or local regulations. The Principal may then negotiate with the Authorities concerned with the object of obtaining agreement to follow this DEP as closely as possible. 1.3DEFINITIONS 1.3.1General definitions The Contractor is the party which carries out all or part of the design, engineering, procurement, construction, commissioning or management of a project, or operation or maintenance of a facility. The Principal may undertake all or part of the duties of the Contractor. The Manufacturer/Supplier is the party which manufactures or supplies equipment and services to perform the duties specified by the Contractor. The Principal is the party which initiates the project and ultimately pays for its design and construction. The Principal will generally specify the technical requirements. The Principal may also include an agent or consultant authorised to act for, and on behalf of, the Principal. The word shall indicates a requirement. The word should indicates a recommendation. DEP 31.40.10.13-Gen. December 1998 Page 4 1.3.2Specific definitions balance lineA small-bore line which allows pressurisation of the barrel on both sides of a pig at the same time. barred teeA tee-piece provided with bars across the internal bore of the side branch to prevent entry of a pig. bypass linePiping between the pipeline and associated plant or facility through which fluid flows under normal operational conditions. cold bendA bend made from linepipe at ambient temperature, normally on the construction site, by a mechanical bending machine. drain lineA small-bore line used to drain fluid from the barrel. end closureA fitting, including a removable part or assembly, which provides quick and easy access to the major barrel when open and seals the bore when closed. hot bendA bend made under factory conditions by hot working billets, plate, pipe etc. kicker line (orPiping from the major barrel to the bypass line used to control the launch or bridle line)receipt of a pig. launchingRetractable pins, used in pig launchers to release a sphere from a cassette pinsholding multiple spheres. main lineThe major portion of a pipeline, between pig traps. major barrelEnlarged pipe section of a pig trap used for loading or retrieval of pigs. minor barrelPipe section of a pig trap between the reducer and the pig trap valve, of the same diameter as the pipeline. pigA device which can be propelled through a pipeline by fluid flow and is normally used for various internal activities such as separating fluids, cleaning and inspecting the pipeline. (A sphere is a spherically shaped pig). pig launcherA pig trap for launching pigs. pig receiverA pig trap for receiving pigs. pig signallerA device set onto or into a pipe which gives an indication of the passage of a pig. pig trapAn ancillary item of pipeline equipment, comprising a barrel, end closure and instruments, for introducing a pig into a pipeline or removing a pig from a pipeline. pig trapA pig trap together with all associated piping, valves, supports and instruments. system pipingPipework associated with the pipeline but not part of the main line. pipingThe standardised piping assemblies contained in DEP 31.38.01.12-Gen. and classesDEP 31.38.01.15-Gen. pressurisingA small-bore line with valves to allow equalisation of pressure across a larger linevalve, avoiding damage to the seats of the larger valve. requisitionthe data/requisition sheet(s) DEP 31.40.10.93-Gen. and DEP 31.40.10.94- Gen., to be used by the Principal and completed by the Contractor. The forms can be found in the requisitioning binder (DEP 30.10.01.10-Gen.). sphere teeA jacketed tee-piece with a perforated inner pipe allowing flow to enter the side branch but preventing entry of a sphere in the side branch. catch pit orDraining facility underneath an end closure. tray tell-tale ventA safety device provided as part of the end closure door locking mechanism to safeguard personnel during door opening. NOTE:Pipe diameters, expressed in inches, are nominal diameters unless specifically mentioned otherwise. DEP 31.40.10.13-Gen. December 1998 Page 5 1.4ABBREVIATIONS ESDEmergency Shutdown HICHydrogen Induced Cracking IDInside Diameter MESCMaterials and Equipment Standards and Code 1.5ACTION ITEMS Items requiring a selection or decision to be made by the Principal are identified by the use of a bullet () in the margin. The required selection shall be indicated on the requisition. 1.6CROSS-REFERENCES Where cross-references to other parts of this DEP are made, the referenced section number is shown in brackets. Other documents referenced in this DEP are listed in (6). DEP 31.40.10.13-Gen. December 1998 Page 6 2.TECHNICAL SPECIFICATION 2.1GENERAL The boundaries of a pig trap system are defined as: -a point on the incoming/outgoing pipeline, on the pipeline side of the main tee but including the main line pig signaller (Figures 1 and 2); -the pipeline side of the isolation valve of connecting facilities (Figures 1 and 2). The main purpose of a pipeline pig trap system is to provide, in a safe manner and without flow interruption, the means to either: -insert and launch a pig into a pipeline; or -receive and retrieve a pig from a pipeline. The sections below describe each pig trap component, in order to give a clear understanding of its purpose, and give detailed minimum requirements. Components and configuration of typical pig traps are shown in (Figures 1 and 2) and the minimum required components for any launcher or receiver are shown in (Figure 3). The requirements for additional components not shown in (Figure 3) shall be determined in accordance with this DEP, based on actual service conditions. DEP 31.40.10.13-Gen. December 1998 Page 7 2.2BARREL The barrel is the section of the pig trap, from the pig trap valve up to and including the end closure, which is required to launch and receive pigs. It shall consist of four parts, as follows: End closureA quick opening closure welded to the major barrel allowing the insertion and removal of pigs. Major barrelAn enlarged section of the barrel used