1、CEN EN*ihL 94 3404589 0095638 242 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 BS 2782 : Part 12 : Method 1214D : 1995 C
2、EN EN*761 94 m 3404589 O095639 189 m of the Standards Board and comes into effect on Amd. No. Date 15 July 1995 O BSI 1995 The foliowing BSI references relate to the work on this standard: Committee reference PRI/61 Draft for comment 92/43170 DC ISBN O 580 24229 3 BS EN 761 : 1995 Text affected Comm
3、ittees responsible for this British Standard The preparation of this British Standard was entrusted to %chnical Committee PRI/61, Plastics piping systems and components, upon which the following bodies were represented: British Gas plc British Plastics Federation British Plumbing Fittings Manufactur
4、ers Association British Valve and Actuator Manufacturers Association Department of the Environment (British Board of Agrement) Department of the Environment (Building Research Establishment) Department of the Environment (Property and Buildings Directorate) Department of Transport Electricity Associ
5、ation 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 Association of Plumbing, Heating and Mechanical Se
6、rvices 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 Contractors The foliowing bodies were also represented in the drafting o
7、f 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 CEN ENS761 94 3404587 0075640 9TO BS EN 761 : 1995 Contents page Committees resp
8、onsible Inside front cover National foreword ii Method Foreword 1 Scope 2 2 Normative references 3 3 Definitions 3 4 Principle 4 5 Apparatus 6 Rst piece 7 Conditioning 8 Procedure 9 Calculation 10 Est report Annex A (informative) Equal increments of lg (the) Bble A.l Times compromising equal increme
9、nts of lg th Figure 8 8 1 Schematic diagram of the apparatus 5 i CEN ENx61 94 m 3404587 0075b4L 837 m BS EN 761 : 1995 National foreword This British Standard has been prepared by Rchnical Committee PRI/61 and is the English language version of EN 761 : 1994 Plasticspiping systems - Glass-r - materi
10、al-dependent requirements are not given; - editorial 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 Euro
11、pean Standard is superseded by this standard. 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 CENKENELEC Rules, the following countries are bound to implement this European Standard. A
12、ustria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. CEN ENJ7bL 74 3404589 0095644 546 1 Scope This European Standard specifies a method for determining the dry creep factor of glas
13、s-reinforced plastics pipes. It is applicable to pipes with an initial specific ring stiffness of not less than 630 N/m, when determined by the method specified in the referring standard. NOTE. For this purpose plates or beam bars are considered to be equally valid for loading the test piece up to a
14、 relative deflection of 28 %. When it is expected that 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 norm
15、ative references are cited at the appropriate places 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 refe
16、rences the latest edition of the publication referred to applies. EN 1228l) Plastics piping systems - Glass-reinforced themnosetting plastics pipes - Determination of the initial specific ring stiffness Plastics piping systems - Glass-reinforced thermosetting plastics pipes and fittings - Methods fo
17、r regression analyses and their use EN 705 3 Definitions 3.1 specific ring stiffness (5) 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
18、 equation: ExI s=- where E I is the apparent modulus of elasticity as determined in the ring stiffness test, in newtons per square metre; is the moment of inertia (the second moment of area) in the longitudinal direction per metre length, expressed in metres to the fourth power per metre, Le.: Page
19、3 EN 761 : 1994 where e d, is the wall thickness of the pipe, in metres; is the mean diameter (see 3.2) of the pipe, in metres. 3.2 mean diameter (d,) The diameter of the circle corresponding with the middle of the pipe wall cross section. It is given, in metres, by either of the following equations
20、: is the average of the measured external diameters, in metres; is the average of the measured wall thicknesses of the pipe, in metres. 3.3 initial specific ring stiffness (SO) The specific ring stiffness when measured 3 min after beginning of loading. It is expressed in newtons per square metre. 3.
21、4 compressive load (F) A load applied to the horizontal pipe to cause a vertical deflection. It is expressed in newtons. 3.5 vertical deflection (y) The vertical change in diameter of a pipe in a horizontal position in response to a vertical compressive load (see 3.4). It is expressed in metres. 3.6
22、 initial deflection (y3 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 conditions ( is the applicable deflection coefficient. 3.10 deflection coefficient u
23、The coefficient which takes into account the second order theory and of which the value is given by the following equation: f = 11860 + (2500 x u/ b) the length of each test piece (see 6,l); c) the number of test pieces (see 6.2); d) if applicable, the conditioning atmosphere and period (see clause
24、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 Cmpresive loading machine, comprising a system by means of which one or more test pieces can be compressed by compressive load determined to an accuracy of 1 % of the maxi
25、mum indicated applied value via two parallel load application surfaces conforming to 5.2. NOTE. Care may be necessary to ensure that the applied load is not affected by friction effects. 5.2 Load application su.rfaces 5.2.1 General. The surfaces shall be provided by a pair of plates conforming to 5.
26、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 the compressive loading machine, as shown in figure 1. The surfaces to be in contact with the test pie
27、ce 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 that no visible bending or deformation of the plate shall occur during the test. 5.2.3 Beam bur. Each be
28、am 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 shall be (20 f 5) mm. For pipes with a nominal size greater than 300 the width of the bar shall be (50 f
29、 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. 5.2.4 D;iwwnsionul measuring devices, capable of determining the necessary dimensions (length, diameters, wall thickness) to an accura
30、cy of within il % and of determining the change in diameter of the test piece in the vertical direction during the test to an accuracy of within fl % of the maximum value of the measured change. NOTE. The maximum value of the change to be measured depends upon the relative deflection specified in th
31、e referring standard. 6 kst piece 6.1 Preparation The test piece shall be a complete ring cut from the pipe to be tested. The length of the test piece shall be as specified in the referring standard, with permissible deviations of f 5 %. The cut ends shall be smooth and perpendicular to the axis of
32、the pipe. Straight lines shall be drawn on the inside or the outside along the length of the test piece and repeated at 60 intervals around its circumference, to serve as reference lines. 6.2 Number The number of test pieces shall be as specified in the referring standard. CEN ENS761 94 3404589 0075
33、646 319 , Detail of beam bar Page 5 EN 761 : 1994 Plate r rnd ttie flat I I mate F I OeReCtbn measurement taken at Wiength of test piece Beam bar Plate laadmg Beam bar loadlng Figure 1. Schematic diagram of the apparatus 7 Conditioning Store the test pieces at the test temperature and relative humid
34、ity specified in the referring standard prior to testing. 6.3 Determination of the dimensions 6.3.1 Length Measure the length of the test piece along each reference line to an accuracy of f 0,5 5%. Calculate the average length, L, of the test piece, in metres. Reject or correct the test piece if it
35、does not conform to 6.1. 6.3.2 Wall thickness Measure to within f 1 % the wall thickness of the test piece at each end of each reference line. Calculate the mean wall thickness, e, as the average of the measured values. 6.3.3 Mean diameter Measure to an accuracy of within f 1,0 % either of the follo
36、wing: a) the internal diameter, o!, of the test piece between each diametrically opposed pair of reference lines at their mid-lengths, e.g. by means of a calliper; b) the external diameter, de, of the test piece which includes the mid-points of the reference lines, e.g. by means of a circumferential
37、 wrap steel tape. Determine the mean diameter, is the logarithm of the calculated deflection at time t = 1 h (a = lg Ylh,l); is the slope of the line; is the time interval between 0,05 h and 1000 h. Calculate the logarithm of the extrapolated deflection at x years using the calculated values of a an
38、d b in the following equation: yx,l,dy is the extrapolated deflection for position 1 at x years under dry conditions, in metres; is the time x years, in hours. tx 9.2 Calculation of the creep factor under dry conditions Calculate the creep factor under dry conditions, ax,dry, using the following equ
39、ation: y3 min.1 fx yx,l,dry f3 min ax,dry (3) where y3 ,in,l is the calculated deflection for position 1 at time t = 3 min (i.e. 0,05 h), in metres; is the extrapolated deflection for position 1 at the time specified in the referring standard, in metres; is the deflection coefficient for the deflect
40、ion at time t = 3 min (i.e. 0,05 h) and has the value given by is the deflection coefficient for the deflection at the time x specified in the referring standard and has the value given by (1860 + (2500 Yx,i,dry/ b) the full identification of the pipe tested; c) the dimensions of each test piece; d)
41、 the number of test pieces; e) the positions in the pipe from which the test pieces were obtained; f) the equipment details, including whether beam bars and/or plates were used; g) the temperature and relative humidity during testing; h) the creep factor under dry conditions, (r-x,dry, for each test
42、 piece; i) the initial specific ring stiffness, So, and the initial specific ring stiffness at position 1, So, 1, for each test piece; j) the deflection at which So is determined; k) the initial deflection; 1) the calculated deflection, 93 min,l, at time t = 3 min (i.e. 0,05 h) for each test piece;
43、m) the extrapolated deflection, yx,l,dry, at the specified time under dry conditions for each test piece; n) a description of the test pieces after testing; o) the age from the time of manufacture of the pipe to the start of the test and conditions of storage during that period (temperature and rela
44、tive humidity); p) any factors which may have affected the results, such as any incidents or any operating details not specified in this standard; q) the dates of the testing period. CEN EN*i(ZLL 94 3404589 0095649 O28 12 589 15 849 19 953 25 119 31 623 525 660 83 1 1047 1318 39 811 50 119 63 096 79
45、433 LOO000 1659 2088 2629 3310 4167 Page 8 EN 761 : 1994 Annex A (informative) Equal increments of lg (time) A. 1 able A. 1 presents intervals of time in minutes, hours or days which correspond to successive equal increments of 0,i in lg th, where th is the time in hours. This information is provide
46、d for assistance in scheduling measurements of the vertical deflection. able A.l Times cornmising eaual increments of 1 43 th me min me min h 75,5 95,l. 120 151 190 1,26 1,58 2,OO 2,51 3,16 0, 052 O, 066 0,083 O, 105 O, 132 23 886 30 071 37 857 47 660 60 O00 239 30 1 370 477 600 3,98 5,Ol 6,31 7,94
47、10.0 O, 166 0,209 0,263 0,331 0,417 75 536 95 094 119 716 150 713 189 737 755 95 1 1197 1507 1897 12,6 15,8 20, o 25,l 31,6 0,525 0,660 0,831 1,05 1,32 238 864 300 712 378 574 476 597 600 O00 2389 3007 3786 4766 6000 39,8 50,l 63,l 79,4 100 1,66 2,09 2,63 3,31 4,17 4,1 492 4,3 474 475 755 355 950 93
48、6 L 197 157 L 507 132 L 897 367 7554 9509 11972 15071 18974 126 158 200 251 316 5,25 6,60 8,31 10,5 13.2 4,6 497 478 479 5.0 2 388 643 3 007 123 3 785 744 i 765 969 ; O00 O00 CEN EN*ibL 74 3404589 0095650 BYT m BS EN 761 : 1995 List of references See national foreword. CEN EN+7bL 94 m 3404589 009565
49、1 786 m BS EN 761 : 1995 BS 2782 : Part 12 : Method 1214D : 1995 BSI 389 Chiswick High Road London W4 4AL 9507- 5- 0.35k- BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Contract requirements 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. Revisions British Standards are
