DEP 32.37.20.10-Gen.pdf

MANUAL INSTRUMENT SIGNAL LINES DEP 32.37.20.10-Gen. July 1999 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 PDF created with pdfFactory Pro trial version www.pdffactory.com means (electronic, mechanical, reprographic, recording or otherwise) without the prior written consent of the copyright owners. PDF created with pdfFactory Pro trial version www.pdffactory.com 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 involvementwith 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 recommendedstandard for good design and engineeringpractice 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 32.37.20.10-Gen. July 1999 Page 2 PDF created with pdfFactory Pro trial version www.pdffactory.com TABLE OF CONTENTS 1.INTRODUCTION .4 1.1SCOPE 4 1.2DISTRIBUTION, APPLICABILITY AND REGULATORY CONSIDERATIONS 4 1.3DEFINITIONS AND ABBREVIATIONS 4 1.4CROSS REFERENCES.5 2.ELECTRICAL CABLING.6 2.1GENERAL6 2.2SIGNAL SEGREGATION IN MULTICORE CABLES. 6 2.3SELECTION AND SPECIFICATION OF INSTRUMENT CABLES 7 2.4CABLES FOR DIGITAL AND VIDEO SIGNALS 9 2.5CABLES FOR SPECIAL APPLICATIONS .9 2.6PROTECTION OF CABLES AGAINST FIRE DAMAGE 9 3.CABLE SEGREGATION, ROUTING AND INSTALLATION . 11 3.1CABLE SEGREGATION11 3.2ROUTING 11 3.3JUNCTION BOXES FOR MULTICORE CABLES12 3.4CABLE GLANDS .12 3.5TRUNKING AND TRAYS.13 3.6TRENCHES.14 3.7CABLE PULLING AND INSTALLATION ASPECTS 14 3.8CONTROL ROOM/AUXILIARY AREAS 15 4.EARTHING AND BONDING .17 4.1GENERAL17 4.2CONNECTIONS TO THE EARTHING SYSTEMS.17 4.3EARTHING OF INTRINSICALLY SAFE CIRCUITRY 18 4.4EARTHING OF CAVITY FLOORS.18 5.LIGHTNING PROTECTION OF INSTRUMENTATION . 19 5.1GENERAL19 5.2INSTRUMENTATION AND CABLING IN THE FIELD . 19 6.PNEUMATIC TUBING.20 6.1GENERAL20 6.2SELECTION AND SPECIFICATION OF TUBING.20 6.3JUNCTION BOXES FOR MULTICORE TUBING 21 6.4INSTALLATION .21 7.IDENTIFICATION AND MARKING .22 7.1IDENTIFICATION OF SYSTEM CABLES22 7.2IDENTIFICATION OF SINGLE CABLES/TUBING.22 7.3IDENTIFICATION OF MULTICORES AND JUNCTION BOXES . 22 7.4MARKING 23 8.REFERENCES 24 APPENDICES APPENDIX 1DISTANCE BETWEEN CABLE TRENCHES 27 APPENDIX 2ARRANGEMENT OF CABLE TRENCHES 28 APPENDIX 3TYPICAL EARTHING AT FAR/CCR.30 APPENDIX 4TYPICAL EARTHING OF INSTRUMENT SIGNAL CABLES IN THE FIELD .31 DEP 32.37.20.10-Gen. July 1999 Page 3 PDF created with pdfFactory Pro trial version www.pdffactory.com APPENDIX 5TYPICAL EARTHING OF INSTRUMENT SIGNAL CABLES IN THE MDF 32 DEP 32.37.20.10-Gen. July 1999 Page 4 PDF created with pdfFactory Pro trial version www.pdffactory.com 1.INTRODUCTION 1.1SCOPE ThisDEPspecifiesrequirementsandgivesrecommendations for thedesignand engineering of instrument signal lines, with immunity from electromagnetic interference as appropriate. It covers design, material selection and installation methods for cabling the signal lines of the different systems. Cabling for transmitting digital and video signals is also covered in this DEP. In the context of this DEP, instrument signal lines include: a)Electricsignallines(paths),includingthermo-electricvoltagelinesfrom thermocouples; lines from transmitters to their receiving instruments, auxiliaries, logic systems, controllers etc. and the lines from these to the relevant actuating elements such as solenoid valves, converters, transducers or control valves. b)Pneumaticsignallines(paths)frompneumatictransmitterstotheirreceiving instruments, auxiliaries, controllers and the lines from these to the relevant final control elements. Signal lines for similar applications such as fire and gas detection and protection systems, plant communication systems, CCTV systems, plant information systems, maintenance management systems and plant security systems are also within the scope of this DEP. This DEP is a revision of the DEP of the same number dated October 1990. 1.2DISTRIBUTION, APPLICABILITY AND REGULATORY CONSIDERATIONS Unless otherwise authorised by SIOP and SIEP, the distribution of this document is confined to companies forming part of or managed by the Royal Dutch/Shell Group, and to contractors and manufacturers nominated by them (i.e. the distribution code is F as defined in DEP 00.00.05.05-Gen.). This DEP is intended for use in oil refineries, chemical plants, gas plants, exploration and production facilities and supply/marketing installations. If national and/or local regulations exist in which some of the requirements are 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, economic and legal aspects. In all cases the contractor shall inform the Principal of any deviation from the requirements of this document 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 document as closely as possible. 1.3DEFINITIONS AND ABBREVIATIONS 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 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. DEP 32.37.20.10-Gen. July 1999 Page 5 PDF created with pdfFactory Pro trial version www.pdffactory.com The word shall indicates a requirement. The word should indicates a recommendation. 1.3.2Specific definitions BondingThe act of connecting together exposed conductive parts and extraneous conductive parts of apparatus, systems or installations that are at essentially the same potential (IEC TR 61000-5-2). Cable ladderAbove-ground, ladder-type cable tray without cover. Cavity floorComputer floor or false floor. Instrument earthDedicated earth for instrument systems. Safety earthPlant safety earth. Sealing fittingConduit fitting which, when filled with a suitable sealing compound, prevents transportation of flammable substances through the conduit. System cablingA wiring concept, consisting of cables, plugs and sockets, as detailed in DEP 32.37.20.31-Gen. TrayAbove-ground, open cable support system, such as U-shaped flat-bottomed or ladder type. TrenchUnderground cable routing system provided with a mechanical protection on top of the cables. TrunkingAbove-ground, U-shaped cable support system with cover. It is flat-bottomed and has a top cover secured by cover clips/fasteners. 1.3.3Abbreviations AL/HDPE/PAAluminium/High Density Polyethylene/Polyamide (nylon) CCRCentral Control Room CCTVClosed Circuit Television DCSDistributed Control System EMElectro magnetic EMCElectro magnetic compatibility EMIElectro magnetic interference FARField Auxiliary Room IPFInstrumented protective function MDFMain Distribution Frame MESCMaterial and Equipment Standards and Code ROVRemote operated valve SWASteel wire armouring SWBSteel wire braiding 1.4CROSS REFERENCES Where cross references to other parts of this DEP are made, the referenced section DEP 32.37.20.10-Gen. July 1999 Page 6 PDF created with pdfFactory Pro trial version www.pdffactory.com number is shown in brackets. Other documents referenced in this DEP are listed in (8). DEP 32.37.20.10-Gen. July 1999 Page 7 PDF created with pdfFactory Pro trial version www.pdffactory.com 2.ELECTRICAL CABLING 2.1GENERAL Single cables are used for signal transmission from field instruments to field mounted junction boxes. Multicore cabling will subsequently transmit the signals from the junction box to an MDF in the CCR or FAR. Wherever possible and consistent with the design of other plant facilities, multicore cabling should be routed underground because it then has inherent protection against fire and mechanical damage. However,above-groundcabling is acceptable, subject to the Principal's approval, provided a definite cost advantage can be demonstrated, or where it is the standard local practice. Outdoor, above-ground and underground cabling shall be provided with steel wire braiding (SWB) or steel wire armouring (SWA) to protect them against mechanical damage and for EMC reasons, even if these cables are installed in trenches / trunking or on cable trays. Underground cabling shall additionally be provided with a chemical/moisture barrier. 2.2SIGNAL SEGREGATION IN MULTICORE CABLES When electrical signals are assigned to multicore cables, the following signal segregation rules shall be followed: Intrinsically safe and non-intrinsically safe signals shall be segregated as required by IEC 60079-14. Segregation on the basis of cabling requirements may be required. Example:Thermocouple signals require extension cabling and thus can only be combined in one cable with signals from thermocouples of the same type. For practical reasons, segregation between disciplines is recommended (e.g. no signal cabling for Instrumentation and Electrical in one multicore cable). The supply and return conductor of a signal shall be contained in the same cable pair. Segregation on the basis of signal level classes shall be applied as shown in Table 1 to achieve EMC. DEP 32.37.20.10-Gen. July 1999 Page 8 PDF created with pdfFactory Pro trial version www.pdffactory.com TABLE 1: CLASSIFICATION OF INSTRUMENT SIGNAL LEVELS SIGNALSIGNAL TYPEEXAMPLES LEVEL CLASS 1Low energy digital systemsComputer bus signals Analogue low level (mV signals)Thermocouples Analogue medium level (approx.Resistance temperature 1V)measurements, analysers 2Analogue high levelElectronic instrumentation loops (e.g. 1-10 VDC, 4-20 mA) Binary low level (below 24 VDCActuating logic systems, and below 0.5 VA)annunciators Digital low l