1、THE ENGINEERING EQUIPMENT AND MATERIALS USERS ASSOCIATION Guide for establishing Operating Periods of Safety Valves PUBLICATION 188 Edition 2 Released by IHS. Not for resale THE ENGINEERING EQUIPMENT AND MATERIALS USERS ASSOCIATION Guide for establishing Operating Periods of Safety Valves PUBLICATIO
2、N 188 Edition 2 Copyright 2009 The Engineering Equipment and Materials Users Association. A company limited by guarantee. Registered in England. Company number 477838. ISBN 0 85931 171 6 Imprint reference 05-2009 Registered and Trading Address 10-12 Lovat Lane London EC3R 8DN Telephone: +44 (0)20 76
3、21 0011 Fax: +44 (0)20 7621 0022 E-mail: saleseemua.org Website: www.eemua.org EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves EEMUA ii ENGINEERING EQUIPMENT AND MATERIALS USERS ASSOCIATION The Engineering Equipment and Materials Users Association, more commonly kno
4、wn as EEMUA, is a European non-profit membership Association helping companies that own or operate industrial facilities - the users of engineering equipment and materials. EEMUA aims to improve the safety, environmental and operating performance of industrial facilities in the most cost-effective w
5、ay, thereby demonstrating and pursuing leadership in asset management. EEMUA Members pursue these aims through collaboration for mutual benefit, sharing engineering experiences and expertise and by promoting their distinct interests as the users of engineering products. Specifically, the aims of EEM
6、UA Member companies are achieved by: providing the organisation within which networking, information sharing and collaboration on non-competitive technical matters can take place; influencing the way written regulations are interpreted and applied in practice; presenting and promoting Members views,
7、 and encouraging the application of good, sound engineering practices; developing user guides, specifications, training and competency schemes; facilitating Members participation in national and international standards making; influencing relevant national and European legislation and regulations. F
8、ormed in 1949 as the Engineering Equipment Users Association, and re-named in 1983 (as a result of taking over the materials association, OCMA), EEMUA has for more than fifty years given companies that own and operate process plants, power stations and other significant industrial facilities, a coll
9、aborative voice in addressing technical and engineering related issues that impact on good integrity management and asset management practices. The Association is open to companies of all sizes that meet its engineering user criteria. Further details of current Members of EEMUA is available on the A
10、ssociations website, www.eemua.org. EEMUA activities often lead to the production of publications. These are prepared for Members use and are often offered for sale as well. A list of EEMUA publications for sale is given at the end of this Publication. The full list is also on the Associations websi
11、te, including details of on-line shopping facilities. To enquire about corporate Membership, write to enquirieseemua.org or call +44 (0)20 7621 0011. EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves EEMUA iii ABOUT THIS PUBLICATION Legal Aspects All rights, title and
12、 interest in this Publication shall belong to EEMUA. All rights are 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 other, without the express prior written agreement
13、 of the EEMUA Executive Director. Infringement of copyright is illegal and also reduces the Associations income thereby jeopardising its ability to fund the production of future publications. It has been assumed in the preparation of this Publication that: the user will ensure selection of those par
14、ts of its contents appropriate to the intended application; and that such selection and application will be correctly carried out by appropriately qualified and competent persons for whose guidance this Publication has been prepared. EEMUA and the individual members of the Work Group that prepared t
15、his EEMUA Publication do not, and indeed cannot, make any representation or give any warranty or guarantee in connection with material contained herein. EEMUA and the individual members of the Work Group that prepared this EEMUA Publication expressly disclaim any liability or responsibility for dama
16、ge or loss resulting from the use or reliance on this Publication. Any recommendations contained herein are based on the most authoritative information available at the time of writing and on current good engineering practice, but it is essential for the user to take account of pertinent subsequent
17、developments and/or legislation. Any person who encounters an inaccuracy or ambiguity when making use of this Publication is asked to notify EEMUA without delay so that the matter may be investigated and appropriate action taken. Consultation and Feedback EEMUA encourages constructive comments on th
18、is Publication from both Members of the Association and others. Comments should be sent on the standard feedback form, a copy of which is provided towards the end of this Publication. An electronic version of the feedback form is available from EEMUA - e-mail your request for a copy to enquirieseemu
19、a.org, telephone your request to +44 (0)20 7621 0011, or download the form from the EEMUA website at www.eemua.org. Submit comments by e-mail (preferred) or post. Comments will be considered by the relevant EEMUA Technical Committee and may be incorporated in future editions of this Publication. New
20、 editions will be publicised on the EEMUA website. EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves EEMUA iv EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves EEMUA v Table of Contents Foreword . 1 1. Scope . 3 2. Introduction . 5 3. O
21、perating and Design Philosophies 7 3.1 Plant Operating Philosophy 7 3.2 Pressure Relieving System Design Philosophy 7 4. Establishing Safety Valve Operating Periods . 9 4.1 General Considerations . 9 4.2 Empirical Approach . 10 4.3 Risk-Based Approach . 10 5. Management Procedures and Record Systems
22、 13 5.1 General . 13 5.2 Procedures 13 5.3 Records: Categorisation of Data 13 5.4 Recorded Information 14 6. References and Bibliography 17 6.1 Standards and Codes 17 6.2 Other Publications . 17 6.3 Bibliography . 17 Appendix 19 A1. Set Pressure Definitions . 19 A2. Effect of Relief System Design 19
23、 A3. Guidelines for accepting new Safety Valves prior to Use . 19 A4. Removal, Inspection and Re-installation . 20 A5. Workshop Maintenance 20 A6. Fluid Categorisation and Plant Operating Environment . 22 A7. Factors to be Considered in the Review Process 23 A8. In-situ Testing and Checking 23 A9. A
24、ction to be taken when a Safety Valve lifts . 26 Table of Figures Figure 1 Model for Reviewing Safety Valve Operating Periods 5 EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves EEMUA vi EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves
25、 EEMUA 1 Foreword This Guide sets out the issues to be considered in determining and reviewing operating periods for safety valves. This is a crucial area for operators of pressure containing plants because it impacts upon both the safe operation of pressure systems and the cost of safety and enviro
26、nmental compliance. If safety valves are not inspected with sufficient frequency they may not operate when called upon to do so, or they may leak. Conversely, unnecessary shutdowns need to be avoided as plant down-time and maintenance are costly. Ideally, a safety valve will be overhauled immediatel
27、y before it fails. In practice, plant operators endeavour to have safety valve inspections coincide with plant outages necessary for other reasons, such as pressure vessel examinations. There is little published guidance to date on establishing valve operating periods and the principal consideration
28、s are not widely appreciated. This Guide seeks to provide the important first step in recognising the main issues and suggests how companies might proceed towards a managed system of review. The information provided reflects good practice. Compliance with this, however, does not imply compliance wit
29、h any particular legislative requirements. Users should satisfy themselves that they comply with the relevant legislation and statutory regulations relating to pressure systems and the use of safety valves. It should also be noted that in certain countries compliance with particular codes or standar
30、ds may be mandatory. In the UK, the governing regulations concerned with in-service pressure systems are The Pressure Systems Safety Regulations 2000, commonly referred to as the PSSR. Although not specifically mentioned in the PSSR, safety valves come under the category of protective devices, and t
31、heir set pressures are dependent on the safe operating limits of the pressure systems and equipment they protect. (The terms in quotation marks in this paragraph are defined in the PSSR.) The EEMUA Pressure Relieving Safety Systems Technical Committee has developed this Guide from the experience and
32、 practices of its member companies in the petroleum, chemical and power industries. The document deals with and expands on issues not fully covered in other publications such as API RP 576 and EI Model Code of Safe Practice Part 12: Pressure vessel examination. This Guide is not intended to be presc
33、riptive. Publications referred to in this document are listed in Chapter 6. EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves EEMUA 2 Note on Terminology The terms relief valve, safety valve and safety relief valve are widely used in industry and have specific meaning
34、s in US standards. However only safety valve is defined in international and British standards and is the term used, generically, in this text without the American distinctions. The term safety valve operating period generally means the period, between successive examinations, in which the valve is
35、in service (precise definitions may vary, see Section 4.1). It is synonymous with inspection interval. Plant operating period is the period between successive overhauls. Revisions to Second Edition This second edition revises and updates the original 1999 edition. The changes made clarify and add im
36、portant points to the existing text and update the references. Units This document employs SI units, but additionally uses Imperial units where appropriate to common usage. EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves EEMUA 3 1. Scope This Guide provides guidance
37、 on establishing operating periods of safety valves and gives further information, beyond the relatively simple statements contained in national codes, to provide a basis for the review of such operating periods. It covers a number of points which may be used as a basis for user company procedures.
38、The main part offers general guidance, whilst the Appendix gives more detail in certain areas, not necessarily referred to in the main text, such as the effect of relief system design (Appendix A2), acceptance of new valves prior to use (Appendix A3), inspection, maintenance and testing (Appendix A4
39、, A5 and A8), and advice on what should be done if a safety valve lifts (Appendix A9). This Guide applies to most pressurised fluid systems and safety valves, including thermal relief and pilot-operated valves, but with the exception of pressure-vacuum (tank breather) type valves. EEMUA Publication
40、188 - Guide for establishing Operating Periods of Safety Valves EEMUA 4 EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves EEMUA 5 2. Introduction Safety valves are items critical to ensuring the integrity of pressurised systems and are often the ultimate protection ag
41、ainst excessive pressure. As mechanical devices, usually with fine tolerances, they may fail to operate, or to operate properly, for a number of reasons (see Appendix A7). It is therefore necessary that a safety valve undergoes periodic inspection and overhaul to ensure that when required to operate
42、 it does so under the conditions and within the limits specified for the particular installation. Although installed primarily for over-pressure protection, a valve may lift below its set pressure, with detrimental environmental or commercial consequences. The process of setting the operating period
43、 of a safety valve should begin with determining an initial operating period followed by subsequent reviews based on operating experience. It is important to appreciate that the operating period selected should be that which is suitable for each safety valve in its specific location. The overall con
44、cept is illustrated in Figure 1. Figure 1 Model for Reviewing Safety Valve Operating Periods EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves EEMUA 6 EEMUA Publication 188 - Guide for establishing Operating Periods of Safety Valves EEMUA 7 3. Operating and Design Phi
45、losophies 3.1 Plant Operating Philosophy Plant operating periods are set by economic and legislative considerations, together with the need for maintenance. Extending the operating period of a plant is usually commercially desirable, but may lead to conflict as this may differ from the safe operatin
46、g periods of the plants safety valves. Such situations require that safety valve operating periods be reviewed by making use of valve operating data employing the empirical approach (see Section 4.2) or by risk-based techniques (see Section 4.3). If this does not resolve the conflict, design modific
47、ations to the safety valve installations may be needed. Consideration should be given to the action to be taken in the event of a safety valve lifting in service, as this will have implications for the operating and system design philosophies. This is discussed in more detail in Appendix A9. 3.2 Pre
48、ssure Relieving System Design Philosophy The design of a plants pressure relieving system should take into account the required operating period of the plant and the likely operating period for each safety valve. Appropriate measures should be taken to accommodate any differences between these perio
49、ds so as to prevent unnecessary plant shutdowns. Points to consider include: single safety valves versus duplication or sparing; safety valve isolation (see EEMUA Publication 184); consequence of a safety valve lifting; requirements for on-line testing. The lack of good detailed design of a safety valve installation can have a deleterious effect on the valves performance which cannot be improved by reducing operating periods or by duplication and isolation. EEMUA Publication 188 - Guide for establishing Operat
