1、CEN EN*744 95 m 3404589 OLL8909 5LT m BRITISH STANDARD Plastics piping and ducting systems - Thermoplastics pipes - Test method for resistance to external blows by the round-the-clock method The European Standard EN 744 : 1995 has the status of a British Standard ICs 23.040.20 NO COPYING WITHOUT BSI
2、 PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 744: 1996 BS 2782 : Part 11 : Method 1108C : 1996 CEN EN*744 95 3404589 OLL89LO 231 BS EN 744 : 1996 Amd. No. of the Standards Board and comes into effect on 15 February 1996 O BSI 1996 Committees responsible for this British Standard Date Text
3、affected 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: Draft for comment 921413382 DC British Gas plc British Plastics Federation British Plumbing Fittings Manufacturers A
4、ssociation British Valve and Actuator Manufacturers Association Department of the Environment (British Board of Agrment) Department of the Environment (Building Research Establishment) Department of the Environment (Property and Building Directorate) Department of Transport Electricity Association F
5、ederation 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 Services
6、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 bodies were also represented in the drafting of the s
7、tandard, through subcommittees and panels: ERA Technology Ltd. Engineering Equipment and Materials Users Association RAPRA Technology Ltd. The following BSI references relate to the work on this standard: I I ISBN O 580 25149 7 BS EN 744 : 1996 Contents Page Committees responsible Inside front cover
8、 National foreword , ii Method Foreword 2 1 Scope 3 2 Definition 3 3 Principle 3 4 Apparatus 3 5 Test pieces 6 6 Conditioning 7 Procedure 8 Expression of results 6 6 7 9 Test report 8 Annex A (informative) Evaluation of results from isolated batches 9 Bbles 1 Dimensions for the nose of the striker 3
9、 2 Mass of strikers 3 3 Number of equidistant lines to be drawn on the test pieces 6 4 Conditioning periods 6 5 Expression of TIR at 10 % depending on the number of blows and failures 7 Figures 1 Typical falling weight testing machine 4 2 Dimensions of strikers 5 3 8 Number of test pieces for 10 % T
10、IR (at 90 % confidence level) O BSI 1996 i - CEN ENx744 95 m 3404589 OLL8912 004 m BS EN 744 : 1996 National foreword This British Standard has been prepared by Technical Committee PRI/61 and is the English language version of EN 744 : 1995 Plastics piping and ducting systems - Thermoplastics pipes
11、- Test method for resistance to external blows by the round-the-clock method, published by the European Committee for Standardization (CEN). It is incorporated into BS 2782 Methods of testing plastics : Part 11 : Thermoplastics pipes, fittings and valves, as Method 1108C : 1995 for association with
12、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 plastics piping systems and components. It has been implemented to enable experience of the method to be gaine
13、d, 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 standard or specification which contains or makes reference to a different test method until that standardi
14、specification has been amended or revised to make reference to this method and adjust any requirements as appropriate. In particular, attention is drawn to the fact that because of e.g. differences in striker geometry, this method is not expected to give identical results to those obtained by refere
15、nce to BS 2782 : Part 11 : Method 1108A : 1989, the use of which should be restricted to its current applications. Pending any related amendment of EN 744 : 1995, attention is drawn to the requirement in clause 6 to use a bath of water and ice for conditioning at O OC, which may inhibit the use of e
16、quipment where the bath liquid temperature is controlled by passage through or past a heat exchanger operating at a lower temperature. Warning note. This British Standard, which is identical with EN 744 : 1995, does not necessarily detail all the precautions necessary to meet the requirements of the
17、 Health and Safety at Work etc. Act 1974. Attention should be paid to any appropriate safety precautions and the method should be operated only by trained personnel. Compliance with a British Standard does not of itself confer immunity from legal obligations. I 11 O BSI 1996 CEN EN*44 95 m 3404589 O
18、LL89L3 T40 W EUROPEAN STANDARD EN 744 NORME EUROPENNE EUROPISCHE NORM April 1995 ICs 23.040.20 Descriptors: plastic tubes, thermoplastic resins, mechanical tests, impact test, shock resistance English version Plastics piping and ducting systems - Thermoplastics pipes - Test method for resistance to
19、external blows by the round- the-clock method Systmes de canalisations et de gaines en plastiques - Tubes thermoplastiques - Mthode dessai de rsistance aux chocs externes par la mthode du cadran Kunststoff-Rohrleitungs- und Schutzrohrsysteme - Rohre aus Thermoplasten - Prfverfahren fr die Widerstand
20、sfhigkeit gegen uBere Schlagbeanspruchung im Umfangsverfahren This European Standard was approved by CEN on 1995-02-06. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without
21、any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made
22、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 official versions. CEN members are the national bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
23、 Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1995 All rights of reproduction and communication in any
24、form and by any means reserved in all countries to CEN and its members Ref. No. EN 744 : 1995 E - CEN ENt44 95 = 3404589 OLL89L4 987 Page 2 EN 744 : 1995 Foreword This European Standard was prepared by GEN/% 155, Plastics piping systems and ducting systems, of which the secretariat is held by NNI. T
25、his European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 1995, and conflicting national standards shall be withdrawn at the latest by October 1995. According to the CENXENELEC Internal Regulations,
26、the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. This standard is based on ISO/DIS 3127 : 1992 Unplastici
27、zed polyvinyl chloride (PVC) pipes for the transport of fluids - Detminution and specvication of resistance to external blows, prepared by the International Organization for Standardization (ISO). It is a modification of ISO/DIS 3127 : 1992 for reasons of applicability to other plastics materials an
28、d/or other test conditions and alignment with texts of other standards on test methods. The modifications are: - no pipe material is mentioned; - test parameters, except those common to all plastics, are omitted; - no material-dependent requirements are given; - editorial changes have been introduce
29、d. The material-dependent parameters and/or performance requirements are incorporated in the system standard(s) concerned. Annex A, which is informative, gives guidance on sampling. No existing European Standard is superseded by this standard. This standard is one of a series of standards on test me
30、thods which support system standards for plastics piping systems and ducting systems. O BSI 1996 - CEN ENa744 95 m 3404589 OLL8915 813 m Type 1 Scope This standard specifies a method for determining the resistance to external blows of thermoplastics pipes with circular cross sections by using the ro
31、und-the-clock method. The method is intended to be applied to isolated batches of pipe. For type testing and audit testing, O OC and/or -20 OC are applicable. NOTE. Pipes made from polypropylene homopolymer (PP-H) which principally can not conform to impact requirements at O OC or lower temperatures
32、 are permitted to be tested at (23 f 2) OC under the condition that PP-H pipes are intended for use for soil and waste discharge and bear an additional marking indicating that they are not to be installed below +5 OC. RS d d, a mm mm 2 Definition For the purposes of this standard, the following defi
33、ni t,ion applies. true impact rate (TIR) The total number of failures divided by the total number of blows, in per cent, as if the whole batch had been tested. NOTE. In practice, test pieces are drawn at random from the batch and the result is only an estimate of the TIR for that batch. 3 Principle
34、Test pieces comprising cut lengths of pipe, representative of a batch or a production run from an extruder, are subjected to blows from a falling weight dropped from a specified height on to specified positions around the circumference of the pipe. The incidence of failure is estimated as the true i
35、mpact rate (TIR) of the batch, or production run, where the maximum value for TIR is 10 %. NOTE 1. The severity of this test method can be adjusted to suit different specification needs by changing the mass of the falling weight and/or by changing the fall height. It is not technically correct to va
36、ry the severity of the test by choosing other values of TIR than that specified in this method. NOTE 2. It should be appreciated that a completely definitive result can only be reached by testing the whole batch, hut in practice a balance is necessary between the statistical possibility of a definit
37、ive result and the cost of further testing. NOTE 3. It is assumed that the following test parameters are set by the standard making reference to this standard: a) the type of striker and striker mass (see b) of clause 4 and item a) of 7.1); b) the drop height for the striker (see d) of clause 4 and
38、7.2, 7.3 andlor 7.4 as applicable); c) the method of sampling (see 5. 1 and c) of clause 9); d) if appropriate, the number of test pieces to be used (see 5.2 and clause 7); e) the test and conditioning temperature and the conditioning medium (see clause ); f) if applicable, any alternative or additi
39、onal criterion for failure (see d) of 7.11. Page 3 EN 744 : 1995 4 Apparatus A falling weight testing machine incorporating the following basic components (see figure 1): a) min frame, with guide rails or a guiding tube rigidly fixed in the vertical position to accommodate a striker (see b) and rele
40、ase it to fall vertically and freely such that the speed of the striker at the moment of hitting the pipe is not less than 95 76 of the theoretical speed; b) striker, having a nose comprising all or part of a hemispherical form combined with a cylindrical stem at least 10 mm long and having dimensio
41、ns conforming to table 1 and figure 2, depending upon the mass of the striker. The mass of the striker, including any associated weights, shall be selected from table 2. Below the stem, the nose shall be of steel with a minimum wall thickness of 5 mm and the striking surface shall be free from imper
42、fections which can influence the results. c) rigid test piece support, consisting of a 120 vee-block at least 200 mm long, positioned so that the axis of the line of fall of the nose of the striker shall intersect the axes of the vee to within f 2,5 mm (see figure i). The support construction shall
43、be sufficiently rigid not to cushion the effect of the impact. d) release mechanism, such that the falling weight can fall from a height which can be adjusted up to at least 2 m, as measured from the top surface of the test piece. d90 I50 190 I *) I *) 1 Not suecified. to allow desim freedom. lhble
44、2. Mass of strikers I Masses in kilograms Mass of striker I 0.005 kg Type d25 2.5 8.0 10,o 12,5 16,O O BSI 1996 CEN EN*44 95 3404589 OLL89Lb 75T Page 4 EN 744 : 1995 A B C O E 1 Guide Graduated scale, vertically adjustable for different sizes of pipe Main frame Striker 120 vee-block Solid base 2,6 m
45、 approximately Figure 1. Typical falling weight testing machine O BSI 1996 CEN ENS744 95 = 3404589 Oll89l7 696 Page 5 EN 744 : 1995 a) Type d25 b) Type d90 Dimensions in millimetres Figure 2. Dimensions of strikers O BSI 1996 CEN EN8744 75 = 3404587 OLL87L8 522 = e 18 ,6 8,6 200 mm. If the applicabl
46、e interval is exceeded, the test piece may still be used if it is returned to the conditioning environment within 10 s of the end of the interval and reconditioned for not less than 5 min. Otherwise the test piece shall be fully reconditioned or discarded; e) for corrugated or ribbed pipe, if the pi
47、tch of the corrugation or ribs is more than 0,225 times the diameter d of the stem of the striker nose (see figure 2), the test piece shall be positioned so that the initial impact of the striker will be on the top of a corrugation or a rib; d) unless otherwise specified by the referring standard, c
48、onsider as failure of the test piece shattering or any crack or split on the inside surface of the pipe that was caused by the impact and that can be seen without magnification: indentation of the test piece or a crease on the surface shall not be taken as a failure. Lighting devices may be used to
49、assist in examining the test pieces. If criteria of failure other than those cited here are used, they shall be listed in the test report. O BSI 1996 CEN ENx744 95 = 3404589 OLL89L9 469 7.2 For pipes with a nominal outside diameter of 40 mm or less, subject each test piece to a single blow, using the appropriate mass of the falling striker and height of fall as specified in the referring standard, and record whether or not it failed (see d) of 7. i. For all other pipe sizes, proceed in accordance with 7.3 unless the referring standard
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