《DD-ENV-1591-2-2001.pdf》由会员分享，可在线阅读，更多相关《DD-ENV-1591-2-2001.pdf（12页珍藏版）》请在三一文库上搜索。
1、DRAFT FOR DEVELOPMENT DD ENV 1591-2:2001 Flanges and their joints Design rules for gasketed circular flange connections Part 2: Gasket parameters ICS 23.040.60 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Licensed Copy: London South Bank University, London South Bank Univer
2、sity, Tue Dec 12 03:00:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD ENV 1591-2:2001 This Draft for Development, having been prepared under the direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 September 2001 BS
3、I 07-2001 ISBN 0 580 37868 3 National foreword This Draft for Development is the English language version of ENV 1591-2:2001. This publication is not to be regarded as a British Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature because it
4、 is considered that further experience is required in its application before it is converted into a British Standard. It should be applied on this provisional basis, so that information and experience of its practical application may be obtained. Comments arising from the use if this Draft for Devel
5、opment are requested so that UK experience can be reported to the European organization responsible for its conversion into a European Standard. A review of this publication will be initiated 2 years after its publication by the European organization so that a decision can be taken on its status at
6、the end of its three-year life. The commencement of the review period will be notified by an announcement in Update Standards. According to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into a European Standard, to e
7、xtend the life of the prestandard or to withdraw it. Comments should be sent in writing to the Secretary of BSI Technical Committee PSE/2, Jointing materials and compounds, at 389 Chiswick High Road, London W4 4AL, giving the document reference and clause number and proposing, where possible, an app
8、ropriate revision of the text. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue und
9、er the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. Summary of pages This document comprises a front cover, an inside front cover, the ENV title page, pages 2 to 8, an inside back cover and a back cover. T
10、he BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 03:00:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN P
11、RESTANDARD PRNORME EUROPENNE EUROPISCHE VORNORM ENV 1591-2 June 2001 ICS 23.040.60 English version Flanges and their joints - Design rules for gasketed circular flange connections - Part 2: Gasket parameters Brides et leurs assemblages - Rgles de calcul des assemblages brides circulaires avec joint
12、- Partie 2: Paramtres de joint Flansche und ihre Verbindungen - Regeln fr die Auslegung von Flanschverbindungen mit runden Flanschen und Dichtung - Teil 2: Dichtungskennwerte This European Prestandard (ENV) was approved by CEN on 10 May 2001 as a prospective standard for provisional application. The
13、 period of validity of this ENV is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the ENV can be converted into a European Standard. CEN members are required to announce the existence of this ENV i
14、n the same way as for an EN and to make the ENV available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the ENV) until the final decision about the possible conversion of the ENV into an EN is reached. CEN members
15、 are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION
16、EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2001 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. ENV 1591-2:2001 E Licensed Copy: London South Bank University, London South Bank University, Tue
17、 Dec 12 03:00:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 2 ENV 1591-2:2001 Contents Page Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、 . . .3 2 Symbols and equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 3 Gasket properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Foreword This European Standard has been prepared by Technical Committee CEN/TC 74 “Flanges an
19、d their joints“, the secretariat of which is held by DIN. EN 1591 consists of two parts: EN 1591-1 Flanges and their joints Design rules for gasketed circular flange connections Part 1: Calculation method ENV 1591-2 Flanges and their joints Design rules for gasketed circular flange connections Part
20、2: Gasket parameters CEN/TC 74 had decided to publish the gasket parameters given in an informative annex to prEN 1591:1994 in the present document as separate prestandard. Data values given in this European Prestandard are based on measurement, on experience, or on estimation. Although currently re
21、garded as the best available information for generic materials, values are only provided for general guidance. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to announce this European Prestandard: Austria, Belgium, Czech R
22、epublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 03:00:15 GMT+00:00 2006, Uncontrolled Copy,
23、 (c) BSI Page 3 ENV 1591-2:2001 1 Scope This European Prestandard specifies gasket parameters for use in EN 1591-1. WARNING The reader is directed to obtain gasket parameters for use in the calculation method given in EN 1591-1 from the gasket supplier. Where this is not possible, then the values in
24、 this document may be used. In the latter case the reader should ensure the latest version of this document is used. If in doubt the national CEN member can be contacted. 2 Symbols and equations Italicised equation numbers are the ones used in part 1 of this standard. When this equation number is in
25、 brackets this denotes that the equation is given here in modified form. Where units are applicable, they are shown in brackets. Where units are not applicable, no indication is given. EG Unloading compression modulus of gasket for I = 0, MPa. E0 The value of EG, extrapolated from measurement values
26、 of EG back to zero stress, Q0 = 0, MPa. K1 Coefficient which determines rate of change of EG with compressive stress. NOTE 1 Gasket unloading compression modulus, EG, is assumed to vary linearily with the maximum stress to which the gasket has been subjected previously, normally the assembly stress
27、 (i.e. load condition I = 0): EG = E0 + K1 Q0(1) NOTE 2 The measurement of EG is made along a chord from Q = Q0 to Q = 0,3 Q0 on a stress/strain curve of the gasket, obtained at unloading. gc Creep factor for gasket NOTE 3 This is an empirical factor which adjusts the compression modulus EG to accou
28、nt, approximately, for any additional compressive displacement UG due to gasket creep, (gc 1). It is defined as: gc = UG(t = 0)/UG(t )(2) and applied as follows: EG(including creep) = gc EG(excluding creep)(3) NOTE 4 For measurements of UG(t ) suitable times such as e.g. 1 000 h are acceptable. I De
29、signates the load condition: I = 0 is the assembly condition, I = 1, 2, . are subsequent conditions including hydraulic testing and all service conditions which could be significant QI Mean effective required gasket compressive stress at load condition I, Mpa Qmax Maximum allowable compressive stres
30、s in the gasket material, Mpa Qmin Minimum necessary compressive gasket stress for assembly condition (I = 0) Mpa NOTE 5 These two parameters define a range of gasket stress between which the gasket behaves in a consistent reliable manner. Below the lower limit Qmin the leak rate may be untypically
31、high and variable, above the upper limit Qmax various gasket properties may be untypical and the gasket may suffer permanent damage. If empirical formulae are fitted to measured gasket properties (e.g. curves of load-compression or stress-leakage rate) the range defines limits of validity of the for
32、mulae. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 03:00:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 4 ENV 1591-2:2001 NOTE 6 Values of Qmax, y are independant of the gasket dimensions and can be obtained approximately as follows: Qmax, y = Qmax, ref
33、/1 + c1 (bg/eg)ref(4a) Values of Qmax depend on gasket dimensions approximately as follows: Qmax = Qmax, ref 1 + c1 (bG/eG)actual/1 + c1 (bG/eG)ref(4b) where c1 is a numerical constant for a gasket type. c1 = 1/20 is a typical value for bonded-fibre sheet gaskets. For gaskets for which no value is a
34、vailable c1 = 0 can be used; and Qmax, ref is the measured value of Qmax for a gasket of radial width (bG)ref and axial thickness (eG)ref. The reference size for a bonded-fibre sheet gasket is 90 mm outside diameter 50 mm inside diameter 2 mm thickness. Qmax., ref includes safety margins which are t
35、he same for all load conditions. NOTE 7 Parameter Qmin serves, in part, the same purpose as “y“ in ASME and related design codes (including BS 5 500 and CODAP) but differs as follows: a)due to the different way in which the effective gasket width is calculated in the ASME Code and the present standa
36、rd, the value of Qmin is not the same as that of y; b)Qmin also serves to define the lower limit of validity of empirical formulae where used to calculate gasket properties. NOTE 8 Qmin is used to define an absolute minimum value of assembly gasket force, FG0 min: FG0 min = AGe Qmin(see equation 49)
37、 (5) where AGe is the effective gasket area and takes account of any reduction of gasket width due to flange rotation at assembly. The following condition is then imposed on the required gasket assembly force: FG0 req FG0 min(see equation 52) (6) Equation 49 is effectively a definition of Qmin. 3 Ga
38、sket properties In Tables 1 to 6 the data in bold were derived recently, the other data were taken from earlier sources. For the latter type of data the tabulated values of QI /P are intended to correspond to a nitrogen gas leak rate of about 1 ml/min (at standard temperature and pressure) at a pres
39、sure P = 40 bar, with a gasket outside diameter dG0 = 90 mm, and gasket inside diameter dGi = 50 mm. NOTE There are few types of gaskets for which thermal expansion coefficients have been measured and therefore none are given in Tables 1 to 6. In those cases where the gasket thermal expansion coeffi
40、cient is not available then the value of the coefficient for the flange material should be used in the calculation. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 03:00:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 5 ENV 1591-2:2001 Table 1 Non-metallic fl
41、at gaskets (soft) and flat gaskets with metal insertion Gasket type and material T C Qmin MPa Qmax, ref MPa E0 MPa K1 QI P gC Rubbera0.60 100 150 0,5 28 18 12 200 200 200 10 10 10 0,9 0,9 0,9 0,9 0,9 0,9 PTFE0.20 100 200 10 50 35 20 600 500 400 20 20 20 1,3 1,3 1,3 0,9 0,7 0,5 Expanded PTFE (ePTFE)
42、0.20 100 200 12 150 150 150 500 1 500 2 500 40 35 30 1,3 1,3 1,3 1 0,9 0,8 Expanded graphite without metal insertion 0.20 100 200 300 10 100 100 95 90 1 1 1 1 26 26 26 26 1,3 1,3 1,3 1,3 1,0 1,0 1,0 1,0 Expanded graphite with perforated metal insertion 0.20 100 200 300 15 150 145 140 130 1 1 1 1 31
43、31 31 31 1,3 1,3 1,3 1,3 1,0 1,0 1,0 1,0 Expanded graphite with adhesive flat metal insertion 0.20 100 200 300 10 100 90 80 70 1 1 1 1 28 28 28 28 1,3 1,3 1,3 1,3 0,9 0,9 0,9 0,9 Expanded graphite with metallic sheets laminated in thin layers with- standing high stresses 0.20 100 200 300 15 270 250
44、230 210 1 1 1 1 33 33 33 33 1,3 1,3 1,3 1,3 1,0 1,0 1,0 1,0 Non-asbestos fibre with binder eG 1 mm 0.20 100 200 40 100 90 70 500 500 500 20 20 20 1,6 1,6 1,6 Non-asbestos fibre with binder eG 1 mm 0.20 100 200 35 80 70 60 500 500 500 20 20 20 1,6 1,6 1,6 a Gasket thickness eG used in the calculation
45、, shall be the thickness under load and the flanges shall be raised faced. NOTE A dash indicates no value available. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 03:00:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 6 ENV 1591-2:2001 Table 2 Grooved steel
46、gaskets with soft layers on both sides Gasket type and material T C Qmin MPa Qmax, ref MPa E0 MPa K1 QI P gC PTFE layers on soft steel0.20 100 200 300 10 350 330 290 250 16 000 16 000 16 000 16 000 1,3 1,3 1,3 1,3 0,9 0,8 0,7 0,6 PTFE layers on stainless steel0.20 100 200 300 10 500 480 450 420 16 0
47、00 16 000 16 000 16 000 1,3 1,3 1,3 1,3 0,9 0,8 0,7 0,6 Graphite layers on soft steel0.20 100 200 300 15 350 330 290 250 16 000 16 000 16 000 16 000 1,3 1,3 1,3 1,3 1,0 1,0 1,0 1,0 Graphite layers on low alloy heat resistant steel 0.20 100 200 300 15 400 390 360 320 16 000 16 000 16 000 16 000 1,3 1
48、,3 1,3 1,3 1,0 1,0 1,0 1,0 Graphite layers on stainless steel0.20 100 200 300 15 500 480 450 420 16 000 16 000 16 000 16 000 1,3 1,3 1,3 1,3 1,0 1,0 1,0 1,0 Silver layers on heat resistant stainless steel 0.20 100 200 300 400 500 600 125 600 570 540 500 460 400 250 20 000 20 000 20 000 20 000 20 000
49、 20 000 20 000 1,8 1,8 1,8 1,8 1,8 1,8 1,8 1,0 1,0 1,0 1,0 1,0 0,9 0,8 NOTE A dash indicates no value available. Table 3 Spiral wound gaskets with soft filler Gasket type and material T C Qmin MPa Qmax, ref MPa E0 MPa K1 QI P gC PTFE filler, outer support-ring0.20 100 200 300 20 110 100 90 80 6 000 6 000 6 000 6 000