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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 751-3 : 1997 Incorp
2、orating corrigendum March 1997 The European Standard EN 751-3 : 1996 has the status of a British Standard ICS 83.140.50; 91.140.40; 91.140.60 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Sealing materials for metallic threaded joints in contact with 1st, 2nd and 3rd family
3、gases and hot water Part 3. Unsintered PTFE tapes Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:44:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 751-3 : 1997 This British Standard, having been prepared under the direction of the Engineering Sector Board, was published under the aut
4、hority of the Standards Board and comes into effect on 15 July 1997 BSI 1997 The following BSI references relate to the work on this standard: Committee reference PSE/2 Draft for comment 94/708887 DC ISBN 0 580 27665 1 Amendments issued since publication Amd. No.DateText affected Committees responsi
5、ble for this British Standard The preparation of this British Standard was entrusted to Technical Committee PSE/2, Jointing materials and compounds, upon which the following bodies were represented: Asbestos Information Centre Ltd. British Adhesives and Sealants Association British Compressed Gases
6、Association British Hydromechanics Research Group Chartered Institution of Water and Environmental Management Energy Industries Council Industrial Water Society LP Gas Association Water Services Association of England and Wales Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:44:40 GMT+00:0
7、0 2006, Uncontrolled Copy, (c) BSI BS EN 751-3 : 1997 BSI 1997i Contents Page Committees responsibleInside front cover National forewordii Foreword2 Text of EN 751-33 Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:44:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii BSI 1997 BS EN 751-3 :
8、1997 National foreword This Part of BS EN 751 has been prepared by Technical Committee PSE/2, and is the English language version of EN 751-3 : 1996 Sealing materials for metallic threaded joints in contact with 1st, 2nd and 3rd family gases and hot water Part 3: Unsintered PTFE tapes incorporating
9、corrigendum March 1997, published by the European Committee for Standardization (CEN). It supersedes BS 6974 : 1991 which is withdrawn. Cross-references International StandardsCorresponding British Standard ISO 7-1BS 21 Specification for pipe threads for tubes and fittings where pressure-tight joint
10、s are made on the threads (metric dimensions) EN 437BS EN 437 Specification for test gases, test pressures and categories of appliance, for gas appliances EN 10242BS EN 10242 Threaded pipe fittings in malleable cast iron Compliance with a British Standard does not of itself confer immunity from lega
11、l obligations. 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. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:44:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN Europea
12、n Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1996 Copyright reserved to CEN members Ref. No. EN 751-3 : 1996 E EUROPEAN STANDARDEN 751-3 NORME EUROPE ENNE EUROPA ISCHE NORM December 1996
13、Incorporating Corrigendum March 1997 ICS 21.140; 23.040.80 Descriptors: Pipe fittings, gas pipes, water pipes, hot water, threaded fittings, sealing materials, tapes, classifications, specifications, dimensional tolerances, effectiveness, dimensional measurements, tests, marking English version Seal
14、ing materials for metallic threaded joints in contact with1st, 2nd and 3rd family gases and hot water Part3. Unsintered PTFE tapes Mate riaux de tache ite pour raccords filete s en contact des gaz de la 1e re, 2e me et 3e me famille et de leau chaude Partie 3: Bandes en PTFE non fritte Dichtmittel f
15、u r Gewindeverbindungen in Kontakt mit Gasen der 1., 2. und 3. Famile und Heibwasser Teil 3: Ungesinterte PTFE-Ba nder This European Standard was approved by CEN on 1996-11-24. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this Eu
16、ropean 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 European Standard exists in three official versions (Engli
17、sh, 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 national standards bodies of Austria, Belgium, Denmark, Fi
18、nland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:44:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 2 EN 751-3 : 1996 BSI 1997 Foreword This
19、European Standard has been prepared by Technical Committee CEN/TC 108 , Sealing materials and lubricants for gas appliances and gas equipment, the secretariat of which is held by NNI. This European Standard shall be given the status of a national standard, either by publication of an identical text
20、or by endorsement, at the latest by June 1997, and conflicting national standards shall be withdrawn at the latest by June 1997. This European Standard consists of the following Parts: Part 1:Anaerobic jointing compounds Part 2:Non-hardening jointing compounds Part 3:Unsintered PTFE tapes This Europ
21、ean Standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries a
22、re bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Contents Page Foreword2 Introduction3 1Scope3 2Normative references3 3Defi
23、nitions3 4Classification of PTFE tapes3 5Requirements4 5.1Requirements to be met by the PTFE tape as received4 5.2Requirements to be met by the PTFE tape after assembly4 5.3Re-test4 6Test material and documentation4 6.1Test material4 6.2Test documentation4 7Test methods5 7.1Test methods for PTFE tap
24、es as received5 7.2Test of PTFE tapes after assembly6 8Marking and instructions7 8.1Marking on packages7 8.2Instructions7 Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:44:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 3 EN 751-3 : 1996 BSI 1997 Introduction This European Standard spe
25、cifies requirements and test methods for tapes produced from virgin unsintered polytetrafluorethylene (PTFE) for use with metallic threaded joints. It defines two classes of PTFE tapes, mainly differing in thickness and mass per area, for fine (F) and coarse (G) threads. A universally applicable PTF
26、E tape may be used for all gas, potable water, and hot water installations. In respect of potential adverse effects of the jointing compounds covered by this European Standard on the quality of water intended for human consumption this standard provides no information as to whether the jointing comp
27、ounds may be used without restriction in any of the Member States of the EU or EFTA. The use and characteristics of the jointing compounds should comply with current regulations, where they exist, depending on the acceptance of verifiable European criteria. Since the application techniques, sometime
28、s due to different pressure limits and safety requirements, differ from country to country, it was rather difficult to harmonize the existing national standards and approval requirements for PTFE tapes. One particular point relates to the adjustment of parts of an installation which sometimes requir
29、e the assembled taper/parallel threaded joints to be turned back up to an angle of 45 . To ensure that PTFE tapes fulfil this requirement in countries where such handling techniques are used, an additional requirement concerning the turn back test was included and such PTFE tapes are additionally de
30、signated with Rp. 1 Scope This European Standard specifies requirements and test methods for unsintered polytetrafluorethylene (PTFE) tapes (hereafter referred to as PTFE tapes) which are suitable for sealing threaded metallic joints as specified in ISO 7-1. The PTFE tapes are typically for use in i
31、nstallations for 1st family gases (town gas), 2nd family gases (natural gas) and 3rd family gases (liquefied petroleum gases (LPG) up to 5 bar and up to 7 bar for hot water of heating systems (Class A) as well as up to 0,2 bar in gas appliances and their auxiliary equipment (Class B). The maximum wo
32、rking pressure covered in this European Standard is 20 bar which is relevant to LPG storage (Class C). The temperature range is limited to 220 C to 125 C. NOTE. For applications outside the scope of this standard (e.g. compressed gases) the purchaser should consult the manufacturer. Anaerobic jointi
33、ng compounds are covered by EN 751-1, non-hardening sealing materials in the form of, e.g. jointing compound paste, are covered by EN 751-2. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are ci
34、ted 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 references the latest editi
35、on of the publication referred to applies. ISO 7-1Pipe threads where pressure-tight joints are made on the threads Part 1: Dimensions, tolerances and designation ISO 228-1Pipe threads where pressure-tight joints are not made on the threads Part 1: Dimensions, tolerances and designation EN 437Test ga
36、ses Test pressures Appliance categories EN 10242Threaded pipe fittings in malleable cast iron prEN 10255Carbon steel tubes suitable for welding or threading prEN 12164Copper and copper alloys Rod for free machining purposes 3 Definitions For the purposes of this European Standard the following defin
37、itions apply: 3.1 PTFE tape Thread sealing tape manufactured from virgin unsintered polytetrafluorethylene (PTFE) without fillers or additives. 3.2 gas family For further information on types of gases see EN 437. 3.3 batch Any quantity of PTFE-tapes manufactured in a single mix at one time. 4 Classi
38、fication of PTFE tapes There are two classes of PTFE tapes, mainly differing in thickness and mass per area, suitable for fine (F) and coarse (G) threads in accordance with table 1. Table 1. Classification of PTFE tapes ClassThreadNominal size F, Frp2)ISO 7-1taper/parallel and taper/taper DN # 101)
39、G, Grp2)ISO 7-1taper/parallel and taper/taper 10 DN # 50 1) Class F tapes may also be used for other dimensions when the number of turns of the thread is $ 7,5 cm21 2) PTFE tapes where limited turning back of taper/parallel threaded joints (R/Rp) is permitted, are additionally marked with Rp. Licens
40、ed Copy: sheffieldun sheffieldun, na, Tue Nov 07 03:44:40 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 4 EN 751-3 : 1996 BSI 1997 5 Requirements 5.1 Requirements to be met by the PTFE tape as received 5.1.1 General The PTFE tape shall be free from any inclusions or imperfections visible to the na
41、ked eye and shall be free from any surface or edge defects, when tested in accordance with 7.1.1. 5.1.2 Tolerances on tape dimensions 5.1.2.1 Length The actual length of the PTFE tape, when tested in accordance with 7.1.2.1, shall not be less than that marked on the spool. 5.1.2.2 Width The actual w
42、idth of the PTFE tape, when tested in accordance with 7.1.2.2, shall not differ from that marked on the spool by more than0,5 mm. NOTE. The preferred width is 12 mm. 5.1.2.3 Thickness The thickness of the PTFE tape, when tested in accordance with 7.1.2.3, shall not differ from the stated value by mo
43、re than10 %. 5.1.3 Tolerances on mass per area The mass per area of the PTFE tape, when tested in accordance with 7.1.3, shall be greater than 90 % of the value declared by the manufacturer. 5.1.4 Residual lubricant content The residual lubricant content of the PTFE tape, when tested in accordance w
44、ith 7.1.4, shall not exceed 0,1 % by mass. 5.1.5 Wrapping properties When wrapped around the specified thread in accordance with 7.1.5, the PTFE tape shall conform to and hold the thread form. The finishing end of the PTFE tape shall remain in position with no tendency to unwind. During wrapping the
45、 PTFE tape shall not break, tear, or split. 5.2 Requirements to be met by the PTFE tape after assembly 5.2.1 Sealing properties When tested in accordance with the methods described in 7.2.1 the PTFE tape shall not permit any leakage, when each test assembly is tested in accordance with 7.2.1.2 to 7.
46、2.1.5 in sequence. 5.2.1.1 Soundness When pressurized, within 1 h after preparation all the joints in the test assemblies shall not leak, when tested in accordance with 7.2.1.2. 5.2.1.2 Soundness after adjustment (additional requirement for Classes FRp and GRp only) After adjusting the test assembli
47、es in accordance with 7.2.1.3 the joint of these test assemblies shall not leak when tested in accordance with 7.2.1.2. NOTE. This additional requirement is only valid for countries in which a limited turning back of prefabricated taper/parallel (R/Rp) threaded joints is permitted. PTFE tapes fulfil
48、ling this requirement should additionally be marked with Rp. 5.2.1.3 Resistance to temperature cycling The sealing properties of the PTFE tapes shall not be impaired by the temperature cycling test in accordance with 7.2.1.4. 5.2.1.4 Resistance to vibration The sealing properties of the PTFE tapes s
49、hall not be impaired by vibration when tested in accordance with 7.2.1.5. 5.2.2 Dismantling When dismantling the screwed joints with commercial tools, after all tests in accordance with 7.2.1 have been completed, there shall be no damage or corrosion of the threads. 5.3 Re-test If more than one joint in all test assemblies should fail throughout the tests specified in 7.2.1.2 to 7.2.1.5 no re-test shall be permitted. Should only one joint fail to comply with the requirements of any test, two further test assemblies shall be prep