1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 1704 : 1997 BS 2782
2、 : Part 11 : Method 1133B : 1997 The European Standard EN 1704 : 1997 has the status of a British Standard ICS 23.060.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Plastics piping systems Thermoplastics valves Test method for the integrity of a valve after temperature cyc
3、ling under bendingBS EN 1704 : 1997 This British Standard, 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 June 1997 BSI 1997 The following BSI references relate to the work
4、 on this standard: Committee reference PRI/61 Draft for comment 95/120948 DC ISBN 0 580 27378 4 Amendments issued since publication Amd. No. Date Text affected Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee PRI/61, Plast
5、ics piping systems and components, upon which the following bodies were represented: British Gas Plc British Plastics Federation British Plumbing Fittings Manufacturers Association British Valve and Actuator Manufacturers Association Chartered Institution of Water and Environmental Management Depart
6、ment of the Environment (British Board of Agre ment) Department of the Environment (Building Research Establishment) Department of Transport Electricity Association Health and Safety Executive Institute of Building Control Institute of Materials Institution of Civil Engineers Institution of Gas Engi
7、neers National Association 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 W
8、ales The following bodies were represented in the drafting of this standard, through subcommittees and panels: ERA Technology Ltd. Engineering Equipment and Materials Users Association RAPRA Technology Ltd.BS EN 1704 : 1997 BSI 1997 i Contents Page Committees responsible Inside front cover National
9、foreword ii Foreword 2 Method 1 Scope 3 2 Normative references 3 3 Principle 3 4 Apparatus 3 5 Test pieces 3 6 Procedure 4 7 Test report 4 Figure 1 Schematic arrangement for bending radius test 5ii BSI 1997 BS EN 1704 : 1997 National foreword This British Standard has been prepared by Technical Comm
10、itte PRI/61 and is the English language version of EN 1704 : 1996 Plastics piping systems Thermoplastics valves Test method for the integrity of a valve after temperature cycling under bending, published by the European Committee for Standardization (CEN). It is incorporated into BS 2782 Methods of
11、testing plastics: Part 11: Thermoplastics pipes, fittings and valves, as Method 1133B : 1997, 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 specificatio
12、n of plastics piping and ducting 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 app
13、ly to any existing standard 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. Cross-references Publication referred to Corresponding
14、British Standard EN 837-1 : 1996 BS EN 837 : 1997 Pressure gauge Part 1: Bourdon tube pressure gauges Dimensions, metrology, requirements and tests EN 28233 BS EN 28233 : 1992 Thermoplastics valves Torque Test method EN 45501 : 1993 BS 2782 : Part 11 : Method 1131 : 1992 BS EN 45501 : 1994 Specifica
15、tion for metrological aspects of non-automatic weighing instruments NOTE 1. In the descriptors, the term cocks should be read as valves. NOTE 2. In 4.1, the specification of the bending frame given in the first paragraph corresponds to that for testing a length of pipe under bending, for which a con
16、stant bending radius can be achieved. This cannot be achieved for a test piece in which a significant portion comprises a relatively stiff valve body. It is necessary therefore to interpret figure 1 as requiring displacement of the valve body by the specified radial distance from its position betwee
17、n two straight pipes before bending is applied. Depending on the relative lengths and stiffness of the valve body and the two adjacent pipes which complete the span shown in figure 1, the radius of bending of the actual pipes may differ from and cannot be expected or required to conform to a constan
18、t radius of 25d n . NOTE 3. In 4.1, reference has been introduced to a specific classification in accordance with EN 45501, which should therefore have been listed as a dated reference in clause 2. NOTE 4. In 5.1.1, reference has been introduced to the MRS-class of the materials of the pipes and the
19、 valve, without reference to the basis thereof. The Technical Committee considers this to be a reference to the classification number according to EN ISO 12162 : 1995 (” BS EN ISO 12162 : 1996 and BS 2782 : Part 11 : Method 1121 : 1996) Warning note. This British Standard, which is identical with EN
20、 1704 : 1997, does not necessarily detail all the precautions necessary to meet the requirements of the 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. In particular, it is the opinio
21、n of UK Technical Committee PRI/61 that the method as written gives test conditions known to be appropriate and required for some applications, including polyethylene valves for gas distribution. For testing of valves of more brittle materials and/or intended for other applications, the test conditi
22、ons may be inappropriate, e.g. conditioning to2 20 C as required for 6.3 and 6.6. The Technical Committee therefore draws particular attention to clause 3 and the note thereto, including item c), and to the note which follows 6.9. Compliance with a British Standard does not of itself confer immunity
23、 from legal obligations. Summary of pages This document comprises a front cover, and inside front cover, pages i and ii, the EN title page, pages 2 to 6, an inside back cover and a back cover.CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Norm
24、ung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 Copyright reserved to CEN members Ref. No. EN 1704 : 1997 E EUROPEAN STANDARD EN 1704 NORME EUROPE ENNE EUROPA ISCHE NORM January 1997 ICS 23.060.00 Descriptors: Plastic tubes, cocks, thermoplastic resins, leak tests, bend tests, ther
25、mal cycling tests, verification English version Plastics piping systems Thermoplastics valves Test method for the integrity of a valve after temperature cycling under bending Syste mes de canalisations en plastique Robinets thermoplastiques Me thode dessai pour la ve rification dun robinet apre s de
26、s cycles thermiques sous flexion Kunststoff-Rohrleitungssysteme Thermoplast-Armaturen Pru fverfahren der Unversehrtheit einder Armatur nach Temperaturwechseln unter Beigung This European Standard was approved by CEN on 1996-10-27. CEN members are bound to comply with the CEN/CENELEC Internal Regulat
27、ions 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 Secretariat or to any CEN member. This Euro
28、pean 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 official versions. CEN members are the nati
29、onal standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 1704 : 1997 BSI 1997 Foreword This European Standard has been prepared by Technical Commit
30、tee CEN/TC 155, Plastics piping systems and ducting systems, the secretariat of which is held by NNI. The material-dependent parameters and/or performance requirements are incorporated in the System Standard(s) concerned. This standard is one of a series of standards on test methods which support Sy
31、stem Standards for plastics piping systems and ducting systems. This 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 July 1997, and conflicting national standards shall be withdrawn at the latest by Ju
32、ly 1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal,
33、Spain, Sweden, Switzerland and the United Kingdom.Page 3 EN 1704 : 1997 BSI 1997 1 Scope This standard specifies a method for determining the leaktightness and ease of operation of a valve under bending following the application of temperature cycling. This standard is applicable to thermoplastics v
34、alves with DN 63 or smaller. 2 Normative references This standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent ame
35、ndments to, or revisions of, any of these publications apply to this standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 837-1 Pressure gauges Part 1: Bourdon tube pressure gauges Dimensions, metrology,
36、requirements and testing EN 28233 Thermoplastics valves Torque Test method 3 Principle A valve assembly is exposed to a continuous temperature cycling between a low and a high temperature for a specified number of cycles. Unless otherwise specified in the referring standard, the lower and upper test
37、 temperatures are220 C and +40 C respectively. During the test the assembly is held at a fixed bend radius. Following temperature cycling the valve is tested for ease of operation and leaktightness. NOTE. It is assumed that the following test parameters are set by the standard making reference to th
38、is standard: a) the bending radius if other than 25 d n (see 5.1.2); b) the number of test pieces to be tested in each configuration (see clause 5); c) the lower and/or upper cycle temperatures, if not as given in 6.3; d) the number of cycles (see 6.4). 4 Apparatus 4.1 A bending frame, capable of pr
39、oducing a constant bending radius of 25 d n , using a three point bending load over a span of 10 d n as shown in figure 1. The stationary frame of the machine shall include two supports, S, with a 5 mm radius of curvature, having parallel axes and adjustable spacing (see figure 1). Depending upon th
40、e type of valve, the moving part of the machine shall make contact via a tool having a 5 mm radius or a semi-cylindrical face or a yoke, the axis of which is parallel to that of the supports. The tool and the supports shall be made of hardened steel. The apparatus shall include force and deflection
41、measuring indicators conforming to accuracy class 2 in accordance with EN 45501. 4.2 A temperature-controlled water bath, maintained at (20 1) C and capable of receiving the bending frame. 4.3 A temperature-controlled environment, capable of receiving the bending frame and being cycled between two t
42、emperatures as specified (see 6.3). 4.4 Other equipment, as follows: a) a device for measuring the operating torque of the valve; b) a compressed air supply, variable up to at least 6 bar (see 6.9); c) a manometer, with a range of 0 mbar to 50 mbar (class 0,6 or better conforming to EN 837-1); d) a
43、thermometer capable of checking conformity to the temperature(s) specified in 4.2 and/or 6.3,a s appropriate; e) end closures connected to the ends of the valve, allowing, by means of an appropriate system, sealing and connecting to the pressurising equipment. By means of an appropriate system, both
44、 end closures shall allow sealing, connection to pressurising equipment and venting (see 6.10 and 6.12). 5 Test pieces 5.1 Preparation 5.1.1 Two test pieces shall be prepared as assemblies as follows. The valve shall be assembled between two pipes of the same d n as the valve and of sufficient lengt
45、h to provide a span of at least 10 d n when the applicable bending radius is achieved (see 5.1.2), as shown in figure 1. The free ends of the pipes shall be fitted with closures conforming to e) of 4.4. If a pipe is to be connected to the valve by fusion, the material of the pipe shall conform to th
46、e same MRS-class as the material of the valve. 5.1.2 One test piece, with the valve fully closed, shall be held in a bending frame (4.1), with the valve spindle in the plane of bending and the operating cap in the outer circumference as shown in figure 1. The assembly shall be put into the bending f
47、rame in such a way that a constant bending radius is assured. Unless otherwise specified in the referring standard, the radius shall be 25 d n .Page 4 EN 1704 : 1997 BSI 1997 The other test piece, with the valve in the half open position, shall be held in a bending frame (4.1) with the valve spindle
48、 perpendicular to the plane of bending. 5.2 Number of test pieces The number of test pieces to be tested in each configuration shall be as specified in the referring standard. 6 Procedure 6.1 Apply the procedures given in 6.2 to 6.12 inclusive to each test piece in each configuration (see clause 5).
49、 6.2 Measure and record the opening and closing torques of the valve in accordance with EN 28233. Restore the valve to its initial position, i.e. closed or half open (see 5.1). 6.3 See c) in the note to clause 3. Place the fixture in a temperature-controlled environment at (220 2) C for 10 h. Then raise the temperature of the environment to (40 2) C and maintain that temperature for 10 h. 6.4 Repeat the temperature cycle given in 6.3 to complete the total number of cycles specified in the referri
