EEMUA PUB NO 211-2014 Guidance on the specification of Pressure vessels (Edition 2).pdf

1、 Guidance on the specification of Pressure vessels PUBLICATION 211 Edition 2 RELEASED BY IHS. NOT FOR RESALE THE ENGINEERING EQUIPMENT AND MATERIALS USERS ASSOCIATION Guidance on the specification of Pressure vessels PUBLICATION 211 Edition 2 Copyright 2014 The Engineering Equipment and Materials Us

2、ers Association. A company limited by guarantee. Registered in England. Company number 477838. ISBN 978-0-85931-201-1 Imprint reference 2-2014 Registered and Trading Address 63 Mark Lane London EC3R 7NQ Telephone: +44 (0)20 7488 0801 Fax: +44 (0)20 7488 3499 E-mail: saleseemua.org Website: www.eemua

3、.org EEMUA Publication 211 - Guidance on the specification of pressure vessels EEMUA ii ENGINEERING EQUIPMENT AND MATERIALS USERS ASSOCIATION About EEMUA The Engineering Equipment and Materials Users Association is usually known by its initials, EEMUA. EEMUA is an Association established by the owne

4、rs and operators of industrial assets. Any organisation that is a substantial user or substantial purchaser of engineering products is eligible to apply to become a member of EEMUA. Membership is subject to the approval of Council. EEMUA Aims EEMUA aims to improve the safety, environmental and opera

5、ting performance of industrial facilities in the most cost-effective way, pursuing and promoting leadership in industrial asset management by sharing engineering experiences and expertise, and by the active, enlightened promotion of the distinct interests of users of engineering products. These aims

6、 are achieved by various means, including: Providing the organisation within which networking, information sharing and collaboration among users on non-competitive technical matters can take place Influencing the way written regulations are interpreted and applied in practice Promoting and presentin

7、g members views, 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 re

8、gulation. The income and resources of EEMUA are applied solely towards the promotion of the aims of the Association. No profit is transferred by way of dividend, bonus or otherwise to members. The work of the Association is mainly carried out by members representatives on EEMUA Technical Committees,

9、 Working Groups, and Forums, supported by EEMUA staff. Incorporation, Membership and Other Information For the purposes of conducting its business, EEMUA is incorporated in England and Wales as a company, limited by guarantee, not having share capital. All usual aspects of company management and bus

10、iness administration are dealt with through the EEMUA Chief Executive, including policy implementation and leadership of the Executive team (the staff). A list of EEMUA publications for sale is given at the end of this Publication. The full list is also on the Associations website, including details

11、 of on-line shopping facilities. To enquire about corporate Membership, write to enquirieseemua.org or call +44 (0)20 7488 0801. EEMUA Publication 211 - Guidance on the specification of pressure vessels EEMUA iii ABOUT THIS PUBLICATION Legal Aspects All rights, title and interest in this Publication

12、 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 of the EEMUA Chief Executive. Infr

13、ingement 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 ensures selection of those parts of its contents appropriate to the inte

14、nded application; and that such selection and application is 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 this EEMUA Publication do not, and indeed cannot

15、, 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 damage or loss resulting from the use or reliance o

16、n 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 developments and/or legislation. Any person who

17、 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 this Publication from both Members of the Associa

18、tion 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 enquirieseemua.org, telephone your request to +44 (0)20 7488

19、 0801, or download the form from the EEMUA website at www.eemua.org. Submit comments by e-mail (preferred) or post. Comments are considered by the relevant EEMUA Technical Committees and may be incorporated in future editions of this Publication. New editions are publicised on the EEMUA website. EEM

20、UA Publication 211 - Guidance on the specification of pressure vessels EEMUA iv EEMUA Publication 211 - Guidance on the specification of pressure vessels EEMUA v Contents Overview vii 1. Considerations on the avoidance of repeat post-weld heat treatment 1 1.1 Introduction . 1 1.2 Exemptions from PWH

21、T given in the codes . 1 1.2.1 When PWHT is a code requirement 1 1.2.2 When PWHT is a service requirement . 3 1.2.3 Further aspects . 4 1.2.4 General requirements for welds where PWHT is waived 5 1.3 Example from the power industry . 6 2. Design for exceptional internal pressure 7 2.1 Introduction .

22、 7 2.1.1 Assumptions . 7 2.2 Design methods 8 2.2.1 Service levels 8 2.2.2 Simple design method 8 2.2.3 Advanced design method . 9 2.3 Testing 10 2.4 Comparison with EN 14460 10 2.5 Further information on containment of exceptional pressures . 11 3. Minimum nozzle loadings and nozzle design 13 3.1 I

23、ntroduction . 13 3.2 Minimum design nozzle loadings . 13 3.2.1 General 13 3.2.2 Vessels in ferritic steels, austenitic steels, duplex SS or nickel alloys . 14 3.2.3 Vessels in glass reinforced plastic 16 3.3 Minimum pipe schedule and standout for nozzles made from pipe . 16 3.3.1 Minimum pipe schedu

24、le 16 3.3.2 Nozzle standout 17 3.4 Small bore nozzle design . 17 4. Evaluating creep damage to pressure equipment . 19 4.1 Introduction/purpose . 19 4.2 Affected materials . 20 4.3 Critical factors 21 4. 4 Design approach 22 4.4.1 Boiler codes 23 4.5 Guidance on assessment of creep damage . 23 4.5.1

25、 Basis of assessment. 24 4.5.2 Assessment of creep 24 4.5.3 Data required . 26 4.5.4 Design /FFS Codes . 27 4.6 Inspection 28 4.6.1 Inspection techniques 30 4.7 Repairs 31 References . 35 EEMUA Publication 211 - Guidance on the specification of pressure vessels EEMUA vi Figures Figure 1 Loading conv

26、ention . 14 Figure 2 Design of NPS 1 (DN 25) or NPS 1 (DN 40) nozzles 18 Figure 3 Header with Serious Creep Damage 19 Figure 4 Uniaxial strain under constant load . 20 Figure 5 Classic and Omega model creep curves . 25 Figure 6 Creep Bulging under internal pressure . 29 Figure 7 Tube rupture caused

27、by short-term overheating . 29 Figure 8 Location of creep induced cracking in welds . 30 Figure 9 Susceptibility to cracking in aged HAZs 32 Tables Table 1 Maximum thickness which may be welded without PWHT for vessels operating above 0C 2 Table 2 Requirement for repeat PWHT on clips welded to vesse

28、ls 3 Table 3 Advanced assessment methods for Levels 1 and 2 based on non-linear behaviour (limit load) 10 Table 4 Class 150/Class 300 nozzle design loads with the vessel design pressure not exceeding 3 bar g 14 Table 5 Class 150/Class 300 nozzle design loads with design pressure greater than 3 bar g

29、 . 15 Table 6 Class 600 nozzle design loads 15 Table 7 Class 900 nozzle design loads 15 Table 8 Minimum design nozzle loadings for vessels in glass reinforced plastic 16 Table 9 Minimum pipe schedule and standout for nozzles made from ferritic steel pipe . 17 Table 10 Creep threshold temperature for

30、 various materials . 21 Table 11 An example of Miners Rule . 25 EEMUA Publication 211 - Guidance on the specification of pressure vessels EEMUA vii Overview The purpose of this Publication is to provide guidance on the specification of pressure vessels for circumstances not addressed in design codes

31、. Additionally, this Publication aims to compare international standards, particularly those from the USA, with UK and European equivalents. It has been prepared by the Pressure Vessels Committee (PRV) of EEMUA, the Engineering Equipment and Materials Users Association. As such, this Publication bri

32、ngs together the practical lessons learnt about design, manufacturing and testing of pressure vessels by users in EEMUA member companies. EEMUA 211 is composed of four Chapters: 1. Considerations on the avoidance of repeat post-weld heat treatment Post-weld heat treatment (PWHT) may be of considerab

33、le importance to the structural integrity of a pressure vessel. This Chapter examines the circumstances under which repeat PWHT may be waived. 2. Design for exceptional internal pressure This Chapter describes methods for assessing both existing and new pressure vessels for exceptional internal pres

34、sures. Simple and advanced design methods are provided for two levels of service performance. 3. Minimum nozzle loadings and nozzle design There are three sections to this Chapter which all relate to improvement in the specification and reliability of nozzles. In the first, tables of minimum design

35、loadings are provided to ensure that nozzles, made in steel, nickel alloys or glass reinforced plastics, are suitable for certain minimum loadings. In the second, requirements on standout and minimum pipe schedule are given for nozzles made from pipe. In the third, particular designs of small bore n

36、ozzles are specified. 4. Evaluating creep damage to pressure equipment This Chapter gives a basic appreciation of creep and how to assess situations where creep is suspected. It primarily intended to be used in relation to pressure vessels and similar equipment but does not specifically address pipi

37、ng where additional factors influence its design and assessment. EEMUA Publication 211 - Guidance on the specification of pressure vessels EEMUA viii EEMUA Publication 211 - Guidance on the specification of pressure vessels EEMUA 1 1. Considerations on the avoidance of repeat post-weld heat treatmen

38、t 1.1 Introduction Post-weld heat treatment (PWHT) relieves the residual stress at welds. It is beneficial in avoiding brittle fracture (for which the design codes give rules) and environmentally assisted cracking (for which purchasers determine requirements). In fabricating new equipment, PWHT may

39、be planned into the manufacturing process and is generally very cost effective. However, with existing vessels, carrying out repeat PWHT may present many practical difficulties. There may be restrictions at the site on keeping the components hot over the length of time needed. It may be difficult or

40、 impossible to provide sufficient heat. Undertaking PWHT in an oven, which is the standard practice for new fabrication, may not be feasible. The disturbance to adjacent equipment caused by carrying out PWHT may also be unacceptable. Occasionally the need may arise to weld on a vessel after its orig

41、inal fabrication and heat treatment has been completed. Such a welding operation might be necessary almost immediately, before or during commissioning the vessel, due to a design change; however, the need is more likely to occur in-service. New clips or studs may be needed for insulation supports or

42、 new anchors for fire-proofing materials. Components such as doubler plates or nozzles may be needed because of corrosion, or due to a process or mechanical design change. Overlay welding may be necessary to build up the thickness of a corroded part. In the extreme, for a major modification, a full

43、circumferential butt-weld may be needed. This Chapter indicates the thicknesses of components on which the codes currently permit welding without PWHT. It also discusses the welding techniques by which welds on thicker components can be made without repeat PWHT. It applies predominantly to vessels m

44、ade in ferritic (i.e. carbon, carbon manganese or low alloy) steels. 1.2 Exemptions from PWHT given in the codes 1.2.1 When PWHT is a code requirement 1.2.1.1 Main pressure parts For avoidance of brittle fracture, PWHT is usually specified for a given material above a certain thickness in the codes.

45、 Table 1 overleaf indicates the maximum thicknesses of components which may be welded without PWHT for vessels operating above 0C in accordance with ASME VIII Div. 1(1)or BSI PD 5500(2). The rules apply particularly to new vessels, but are also a major influence when the feasibility of modifying exi

46、sting vessels is under review. Table 1 applies to the greater thickness of the two components being welded. A vessel may have been given PWHT because of the thickness of the main plates, but it may be that the proposed modification is on a component with a thickness less than that shown in Table 1 o

47、verleaf. For example, if the modification is to a nozzle and the wall thickness of the nozzle is less than that in Table 1, welding to the nozzle - a new flange for example - is permissible without repeat PWHT. Care EEMUA Publication 211 - Guidance on the specification of pressure vessels EEMUA 2 sh

48、ould be taken that the length of the nozzle is such that the heat of welding does not affect the shell. The flange itself should be checked for the need for PWHT and rules are given in the codes for determining the nominal thickness for resistance to brittle fracture of different components, e.g. fl

49、anges and compensation pads. Table 1 Maximum thickness which may be welded without PWHT for vessels operating above 0C Code Material ASME P1/ BSI PD 5500 Band M0 or given PWHT to avoid process side environmentally assisted cracking (see Section 1.2.2); or subjected to PWHT because of code requirements to avoid brittle fracture. The requirement for repeat PWHT is given in Table 2 as either a YES or a NO. EEMUA Publication 211 - Guidance on the specification of pressure vessels EEMUA 3 Table 2 Requirement for repeat PWHT on clips we