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1、BRITISH STANDARD BS EN 761:1995 BS 2782-12: Method 1214D:1995 Plastics piping systems Glass-reinforced thermosetting plastics (GRP) pipes Determination of the creep factor under dry conditions The European Standard EN 761:1994 has the status of a British Standard BS EN 761:1995 This British Standard
2、, having been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 July 1995 BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference PRI/61 Draft fo
3、r comment 92/43170 DC ISBN 0 580 24229 3 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee PRI/61, Plastics piping systems and components, upon which the following bodies were represented: British Gas plc British Plastics F
4、ederation British Plumbing Fittings Manufacturers Association British Valve and Actuator Manufacturers Association Department of the Environment (British Board of Agreement) Department of the Environment (Building Research Establishment) Department of the Environment (Property and Buildings Director
5、ate) Department of Transport Electricity Association Federation of Civil Engineering Contractors Health and Safety Executive Institute of Building Control Institute of Materials Institution of Civil Engineers Institution of Gas Engineers Institution of Water and Environmental Management National Ass
6、ociation of Plumbing, Heating and Mechanical Services Contractors Pipeline Industries Guild Plastics Land Drainage Manufacturers Association Society of British Gas Industries Society of British Water Industries Water Companies Association Water Services Association of England and Wales The following
7、 bodies were also represented in the drafting of the standard, through subcommittees and panels: Association of Consulting Engineers Engineering Equipment and Materials Users Association Institution of Mechanical Engineers RAPRA Technology Ltd. Water Research Centre Amendments issued since publicati
8、on Amd. No. DateComments BS EN 761:1995 BSI 11-1999i Contents Page Committees responsibleInside front cover National forewordii Foreword2 1Scope3 2Normative references3 3Definitions3 4Principle4 5Apparatus4 6Test piece5 7Conditioning6 8Procedure6 9Calculation6 10Test report7 Annex A (informative) Eq
9、ual increments of lg (time)8 Figure 1 Schematic diagram of the apparatus5 Table A.1 Times compromising equal increments of lg th8 List of referencesInside back cover BS EN 761:1995 ii BSI 11-1999 National foreword This British Standard has been prepared by Technical Committee PRI/61 and is the Engli
10、sh language version of EN 761:1994 Plastics piping systems Glass-reinforced thermosetting plastics (GRP) pipes Determination of the creep factor under dry conditions, published by the European Committee for Standardization (CEN). It is incorporated into BS 2782 Methods of testing plastics Part 12: R
11、einforced plastics pipes, fittings and valves, as Method 1214D:1995, for association with related test methods for plastics materials and plastics piping components. This test method has been prepared for reference by other standards under preparation by CEN for specification of reinforced plastics
12、piping systems and components. It has been implemented to enable experience of the method to be gained and for use for other fresh applications. It is also for use for the revision or amendment of other national standards as practicable, but it should not be presumed to apply to any existing standar
13、d or specification which contains or makes reference to a different test method until that standard/specification has been amended or revised to make reference to this method and adjust any requirements as appropriate. NOTEReference is also made to EN 1228 prior to its publication. When that is publ
14、ished it is intended that the corresponding British Standard will carry the references BS EN 1228 and BS 2782-12: Methods 1214A and B. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application.
15、Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references Publication referred toCorresponding British Standard EN 705:1994BS EN 705:1995 BS 2782-12: Methods 1220A, B and C:1995 Plastics piping systems Glass-reinforced thermosetting plastics (GRP)
16、 pipes and fittings Methods of regression analysis and their use Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had
17、 amendments incorporated. This will be indicated in the amendment table on the inside front cover. ? EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 761 April 1994 UDC 621.643.2-036.067.5:620.1:539.3 Descriptors: Pipelines, plastic tubes, reinforced plastics, glass reinforced plastics, thermose
18、tting resins, creep properties, deflection, tests, computation English version Plastics piping systems Glass-reinforced thermosetting plastics (GRP) pipes Determination of the creep factor under dry conditions Systmes de canalisations plastiques Tubes en plastiques thermodurcissables renforc de verr
19、e (PRV) Dtermination du coefficient de fluage en condition sche Kunststoff-Rohrleitungssysteme Rohre aus glasfaserverstrkten duroplastischen Kunststoffen (GFK) Bestimmung des Kriechfaktors im trockenen Zustand This European Standard was approved by CEN on 1994-04-27. CEN members are bound to comply
20、with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secret
21、ariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the offici
22、al versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de No
23、rmalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1994 Copyright reserved to CEN members Ref. No. EN 761:1994 E ? EN 761:1994 BSI 11-1999 2 Foreword This European Standard was prepared by CEN/TC 155, Plastics piping systems and ducting systems. This
24、standard is based on document N 129 Glass reinforced thermosetting plastics (GRP) pipes and fittings Test method for the determination of creep factor of pipes under dry conditions prepared by working group 1 of Subcommittee 6 of Technical Committee 138 of the International Organization for Standard
25、ization (ISO). It is a modification of document ISO/TC 138/SC 6/WG 1 N 129 for reasons of possible applicability to other test conditions and alignment with texts of other standards on test methods. The modifications are: test parameters are omitted; material-dependent requirements are not given; ed
26、itorial changes have been introduced. The material-dependent test parameters and/or performance requirements are incorporated in the referring standard. Annex A, which is informative, is given to assist the scheduling of data measurement. No existing European Standard is superseded by this standard.
27、 This standard is one of a series of standards on test methods which support System Standards for plastics piping and ducting systems. In accordance with the Common CEN/CENELEC Rules, the following countries are bound to implement this European Standard. Austria, Belgium, Denmark, Finland, France, G
28、ermany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. ? EN 761:1994 BSI 11-19993 1 Scope This European Standard specifies a method for determining the dry creep factor of glass-reinforced plastics pipes. It is applicable to pi
29、pes with an initial specific ring stiffness of not less than 630 N/m, when determined by the method specified in the referring standard. NOTEFor this purpose plates or beam bars are considered to be equally valid for loading the test piece up to a relative deflection of 28 %. When it is expected tha
30、t the relative deflection will be more than 28 %, then the test is to be conducted using beam bars (see 8.3). 2 Normative references This European Standard incorporates by dated or undated references, provisions from other publications. These normative references are cited at the appropriate places
31、in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred
32、 to applies. EN 1228, Plastics piping systems Glass-reinforced thermosetting plastics pipes Determination of the initial specific ring stiffness1). EN 705, Plastics piping systems Glass-reinforced thermosetting plastics pipes and fittings Methods for regression analyses and their use. 3 Definitions
33、3.1 specific ring stiffness (S) a physical characteristic of the pipe which is a measure of the resistance to ring deflection under external load this characteristic is determined by testing and is defined, in newtons per square metre, by the equation: where where 3.2 mean diameter (dm) the diameter
34、 of the circle corresponding with the middle of the pipe wall cross section it is given, in metres, by either of the following equations: dm= di+ e dm= dee where 3.3 initial specific ring stiffness (S0) the specific ring stiffness when measured 3 min after beginning of loading it is expressed in new
35、tons per square metre 3.4 compressive load (F) a load applied to the horizontal pipe to cause a vertical deflection it is expressed in newtons 1)At present prEN 1228. S EI dm3 - -= Eis the apparent modulus of elasticity as determined in the ring stiffness test, in newtons per square metre; Iis the m
36、oment of inertia (the second moment of area) in the longitudinal direction per metre length, expressed in metres to the fourth power per metre, i.e.: eis the wall thickness of the pipe, in metres; dmis the mean diameter (see 3.2) of the pipe, in metres. diis the average of the measured internal diam
37、eters, in metres; deis the average of the measured external diameters, in metres; eis the average of the measured wall thicknesses of the pipe, in metres. I e3 12 - -= ? EN 761:1994 4 BSI 11-1999 3.5 vertical deflection (y) the vertical change in diameter of a pipe in a horizontal position in respon
38、se to a vertical compressive load (see 3.4) it is expressed in metres 3.6 initial deflection (y3 min) the vertical deflection caused by the compressive load and measured 3 min (i.e. 0,05 h) after the beginning of loading it is expressed in metres 3.7 long-term vertical deflection under dry condition
39、s (yx, dry) the estimated vertical deflection after x years, obtained by extrapolation of long-term deflection measurements at a constant load under dry conditions it is expressed in metres 3.8 dry conditions the test environment in air at the prevailing humidity 3.9 dry creep factor (x, dry) the fa
40、ctor given by the following equation: where 3.10 deflection coefficient (f) the coefficient which takes into account the second order theory and of which the value is given by the following equation: f = 1860 + (2500 y/dm) 105 4 Principle A cut length of pipe is subjected to a constant load along it
41、s length to compress it diametrically for a period of not less than 1 000 h. Its deflection is measured at intervals. The deflection after a specified time of x years is estimated by extrapolation. The creep factor under dry conditions is determined from the relationship between the initial deflecti
42、on and the deflection after x years of the same test piece (see 3.7 and 3.8). NOTE 1If it is required to predict the deflection at 50 years this requires extrapolating approximately 2,5 decades (2,5 increments of lg t, where t is time in hours). In order to improve the reliability of the prediction
43、the creep test may be extended beyond 1 000 h. NOTE 2It is assumed that the following test parameters are set by the standard making reference to this standard: a) the time to which the values are to be extrapolated (see 3.6, 3.7, 3.9 and clause 9); b) the length of each test piece (see 6.1); c) the
44、 number of test pieces (see 6.2); d) if applicable, the conditioning atmosphere and period (see clause 7); e) the test temperature and relative humidity (see 8.1); f) the periods of test pieces under load (see 8.4). 5 Apparatus 5.1 Compressive loading machine, comprising a system by means of which o
45、ne or more test pieces can be compressed by compressive load determined to an accuracy of 1 % of the maximum indicated applied value via two parallel load application surfaces conforming to 5.2. NOTECare may be necessary to ensure that the applied load is not affected by friction effects. 5.2 Load a
46、pplication surfaces 5.2.1 General. The surfaces shall be provided by a pair of plates conforming to 5.2.2, or a pair of beam bars conforming to 5.2.3, or a combination of one such plate and one such bar, with their major axes perpendicular to and centred on the direction of application of load F by
47、the compressive loading machine, as shown in Figure 1. The surfaces to be in contact with the test piece shall be flat, smooth, clean and parallel. 5.2.2 Plate. Each plate shall have a length at least equal to the length of the test piece (see 6.1), a width of at least 100 mm and a thickness such th
48、at no visible bending or deformation of the plate shall occur during the test. 5.2.3 Beam bar. Each beam bar shall be rigid, have rounded edges and shall have a length at least equal to the length of the test piece (see 6.1). For pipes with a nominal size of not more than 300 the width of the bar sh
49、all be (20 5) mm. For pipes with a nominal size greater than 300 the width of the bar shall be (50 5) mm. Each bar shall be so constructed and supported that other surfaces of the beam bar structure shall not come into contact with the test piece during the test. xindicates a specified period of time, in years; fis the applicable deflection coefficient. x, dry Y3 min Yx, dry - - fx f3 min - = ? EN 76