DEP 31.21.70.31-Gen.pdf

TECHNICAL SPECIFICATION AIR-COOLED HEAT EXCHANGE EQUIPMENT (AMENDMENTS/SUPPLEMENTS TO API STANDARD 661) DEP 31.21.70.31-Gen. December 1993 DESIGN AND ENGINEERING PRACTICE USED BY COMPANIES OF THE ROYAL DUTCH/SHELL GROUP 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 Internationale Petroleum Maatschappij B.V., The Hague, the Netherlands. The copyright of this document is vested in Shell Internationale Petroleum Maatschappij B.V., The Hague, the Netherlands. 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 owner. 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 31.21.70.31-Gen. December 1993 Page 2 TABLE OF CONTENTS PART IINTRODUCTION.4 1.1SCOPE 4 1.2DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS4 1.3DEFINITIONS 4 1.4CROSS-REFERENCES4 PART IIGENERAL INFORMATION.5 2.1DESIGN RULES5 2.2UNITS OF MEASUREMENT.5 2.3EQUIPMENT NUMBERING5 PART IIIGENERAL REQUIREMENTS.6 3.1SELECTION OF TYPES6 3.2THERMAL DESIGN OR RATING7 3.3REQUIREMENTS AND SCOPE OF SUPPLY8 PART IVAMENDMENTS/SUPPLEMENTS to API STANDARD 661.9 SECTION 1 GENERAL 9 SECTION 2 PROPOSALS.10 SECTION 3 DOCUMENTATION.11 SECTION 4 DESIGN. 12 SECTION 5 MATERIALS 19 SECTION 6 FABRICATION.20 SECTION 7 INSPECTION, EXAMINATION AND TESTING21 SECTION 8 PREPARATION FOR SHIPMENT.22 SECTION 9 SUPPLEMENTAL REQUIREMENTS23 APPENDIXDATA SHEETS24 PART VREFERENCES25 PART VIAPPENDICES28 APPENDICES APPENDIX 1STANDARD FORMS, REQUISITION AND DATA/REQUISITION SHEETS.29 APPENDIX 2COMPLETION OF DATA/REQUISITION SHEETS.30 APPENDIX 3DETAIL OF TWO-PART PLUG WITH GASKET COMPRESSOR31 APPENDIX 4TYPICAL WELDING DETAILS32 DEP 31.21.70.31-Gen. December 1993 Page 3 PART IINTRODUCTION 1.1SCOPE This DEP, which is a revision of an earlier DEP with the same title and number dated October 1982, gives amendments and supplements to API Standard 661, 'Air-Cooled Heat Exchangers for General Refinery Service', Third Edition, April 1992. Ambiguities or contradictions stemming from the publication of later revisions and/or amendments to API Standard 661 shall be referred to the Principal. 1.2DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS Unless otherwise authorised by SIPM, 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 defined in DEP 00.00.05.05-Gen.). It is intended that API Standard 661 together with this DEP shall be used for horizontal air-cooled heat exchange equipment in oil refineries, chemical plants, gas plants, and exploration and production facilities. 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 Authorities concerned with the object of obtaining agreement to follow this DEP as closely as possible. 1.3DEFINITIONS For the purpose of this DEP, the following definitions shall hold: 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 air-cooled heat exchange equipment and services to perform the duties specified by the Contractor. The terms Supplier and Manufacturer as used in this DEP are synonymous with the term Vendor (as used in API Standard 661) depending on the context in which the term is used. The Principal is the party which initiates the project work 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, authorized to act for the Principal. The word shall indicates a requirement. The word should indicates a recommendation. 1.4CROSS-REFERENCES Where cross-references to other parts of this DEP are made, the referenced section number is shown in brackets. Other standards/publications referred to in this DEP are listed in Part V. DEP 31.21.70.31-Gen. December 1993 Page 4 PART II GENERAL INFORMATION 2.1DESIGN RULES The design, materials, fabrication, inspection, testing and preparation for shipment of air-cooled heat exchangers shall be based on API Standard 661, Third Edition, April 1992 as amended/supplemented by this DEP. For clarity and ease of reference, the section and clause numbering of API Standard 661 has been followed throughout Part IV of this DEP. The sections/clauses in the API Standard 661 not amended by this DEP remain valid as written. Deviations from this DEP are not permitted without the prior written approval of the Principal. Such approval shall be valid only for a specific case, and shall not be construed as having general validity for wider application. In case of conflict between documents relating to an order, the following hierarchy shall apply: 1.The purchase order 2.This DEP In case of conflict, the Principal shall be consulted in writing. When specifying an air-cooled heat exchanger, the applicable data/requisition sheets listed in Appendix 1 of this DEP shall be used, completed in accordance with Appendix 2 of this DEP. The Manufacturer/Supplier who performs the thermal design or rating of an air-cooled heat exchanger shall be responsible for the thermal design or rating. In case of a proprietary design, the Manufacturer/Supplier shall contact the Principal to agree on the calculation method and the degree of responsibility. Air-cooled heat exchangers shall be considered to be pressure vessels. The main mechanical design code shall be ASME Boiler and Pressure Vessel Code Section VIII, Division 1 or 2, as amended/supplemented by DEP 31.22.20.31-Gen. Only requirements additional to those in the ASME code and DEP 31.22.20.31-Gen. are stated in this DEP. In all cases the Principal shall specify the mechanical design code on the data/requisition sheet and, where applicable, in the Project Specification or BDEP (“Basis of Design Package“). 2.2UNITS OF MEASUREMENT The SI unit system has been applied in this DEP and, where considered necessary, the metric sizes are followed by their imperial equivalents in brackets. TheuseofSI units onthe data/requisition sheets shall be in accordance with DEP 00.00.20.10-Gen. Care shall always be taken to indicate whether absolute pressure or gauge pressure is intended. If bar is used as unit of pressure, this shall be qualified as bar (abs) or bar (ga), as applicable. 2.3EQUIPMENT NUMBERING Heat transfer equipment shall be identified by a specific equipment number in accordance with DEP 31.10.03.10-Gen. Equipment consisting of one or more tube bundles connected in series or parallel and performing a common duty is termed an item. In such cases, the item as a whole is identified by the specific equipment number, and each bundle within the item is separately identified by the addition of a capital letter in alphabetical progression, e.g. E-101A, E-101B, E-101C, etc. Each unique motor/fan combination shall have an equipment number which may differ from the bundle number. Identical motor/fan combinations in a bank shall be numbered in alphabetical progression, e.g. EM-110A, EM-110B, EM-110C, etc. DEP 31.21.70.31-Gen. December 1993 Page 5 PART III GENERAL REQUIREMENTS 3.1SELECTION OF TYPES 3.1.1Air-cooled heat exchanger type For refinery services the horizontal air-cooled heat exchanger shall be applied, either forced draught or induced draught, so that several air-cooled heat exchangers can be grouped into one bank. Vertical, “V“ frame and “A“ frame or “roof“ type air-cooled heat exchangers are not covered by the API Standard 661 or this DEP. The selection of one of these types of air-cooled heat exchangers requires prior agreement of the Principal. Where, for reasons of control, an air-cooled heat exchanger has to be provided with variable speed fans (“speed frequency control“, SFC) or automatic variable-pitch fans (AVP), it shall not share its fans with air-cooled heat exchangers on other duties. For items consisting of parallel bays, where it is specified that less than 100% of the fans shall have variable speed fans or automatic variable-pitch fans, the following shall be taken into account: -the parallel bays shall be identical -the fan arrangement shall be symmetrical -in the case of 2 fans per bay, the controlled fan shall be at the hottest end of the bundle -in the case of 2 or more controlled fans per item, the control shall be equal and simultaneous for all controlled fans. Where air-cooled heat exchangers share fans in compliance with the above requirements, their respective tube bundles shall have an equal number of tube rows, the tubes shall be of equal size with identical finning characteristics, and the pitch of the tubes shall be identical. 3.1.2Forced draught versus induced draught Forced draught shall be selected for all non critical applications. Forced draught shall also be selected for critical applications (for which the air design temperature is exceeded for 40 hours a year) if the difference between the design product outlet temperature and the design air inlet temperature is 15 °C or higher. However, in case of stringent noise limitations, e.g. sound pressure level requirements of maximum 80 dB(A), the use of an induced draught air-cooled heat exchanger may be considered. For critical applications, if the product outlet temperature is less than 15 °C above the design air inlet temperature, induced draught shall be used providing none of the limits