1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 751-2 : 1997 The Eu
2、ropean Standard EN 751-2 : 1996 has the status of a British Standard ICS 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 gases and hot water Part 2. Non-hardening jointi
3、ng compoundsBS EN 751-2 : 1997 This British Standard, having been prepared under the direction of the Engineering Sector Board, was published under the authority 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: Co
4、mmittee reference PSE/2 Draft for comment 94/708886 DC ISBN 0 580 27664 3 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 PSE/2, Jointing materials and compo
5、unds, upon which the following bodies were represented: Asbestos Information Centre Ltd. British Adhesives and Sealants Association British Compressed Gases Association British Hydromechanics Research Group Chartered Institution of Water and Environmental Management Energy Industries Council Industr
6、ial Water Society LP Gas Association Water Services Association of England and WalesBS EN 751-2 : 1997 BSI 1997 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN 751-2 3ii BSI 1997 BS EN 751-2 : 1997 National foreword This Part of BS EN 751 has been
7、 prepared by Technical Committee PSE/2, and is the English language version of EN 751-2 : 1996, Sealing materials for metallic threaded joints in contact with 1st, 2nd and 3rd family gases and hot water Part 2: Non-hardening jointing compounds, published by the European Committee for Standardization
8、 (CEN). It supersedes BS 6956 : Part 6 : 1992 which is withdrawn. Cross-references International Standards Corresponding British Standard ISO 7-1 BS 21 Specification for pipe threads for tubes and fittings where pressure-tight joints are made on the threads (metric dimensions) EN ISO 2160 BS EN ISO
9、2160 Petroleum products. Corrosiveness to copper. Copper strip test EN 437 BS EN 437 Specification for test gases, test pressures and categories of appliance, for gas appliances EN 10242 BS EN 10242 Threaded pipe fittings in malleable cast iron Compliance with a British Standard does not of itself c
10、onfer immunity from legal 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.CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komi
11、tee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1996 Copyright reserved to CEN members. Ref. No. EN 751-2 : 1996 E EUROPEAN STANDARD EN 751-2 NORME EUROPE ENNE EUROPA ISCHE NORM December 1996 ICS 21.140; 23.040.80 Descriptors: Pipe fittings, gas pipes, water pipes, hot wate
12、r, threaded fittings, sealing materials, classifications, specifications, tests, effectiveness, marking English version Sealing materials for metallic threaded joints in contact with 1st, 2nd and 3rd family gases and hot water Part 2: Non-hardening jointing compounds Mate riaux de tanche ite pour ra
13、ccords filete se n contact des gaz de la 1e re, 2e me et 3e me famille et de leau chaude Partie 2: Composition de tanche ite non durcissante Dichtmittel fu r Gewindeverbindungen in Kontakt mit Gasen der 1., 2. und 3. Familie und Heiwasser Teil 2: Nichtausha rtende Dichtmittel This European Standard
14、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 European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nati
15、onal 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 by translation under the responsibility of a CEN member into its own language and no
16、tified to the Central Secretariat has the same status as the official 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 King
17、dom.Page 2 EN 751-2 : 1996 BSI 1997 Foreword This 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 stan
18、dard, either by publication of an identical text 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 jointin
19、g compounds Part 3: Unsintered PTFE tapes This European 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
20、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, Spain, Sweden, Switzerland and the United Kingdom. Contents Page Foreword
21、 2 Introduction 3 1 Scope 3 2 Normative references 3 3 Definitions 4 4 Classification of jointing compounds 4 5 Requirements 4 5.1 Requirements to be met by the jointing compound as received 4 5.2 Requirements to be met by the jointing compound after assembly 4 5.3 Re-test 5 6 Test material and docu
22、mentation 5 6.1 Test material 5 6.2 Test documentation 5 7 Test methods 5 7.1 Test methods for jointing compounds as received 5 7.2 Test of jointing compounds after assembly 6 8 Marking and Instruction 7 8.1 Marking on packages 7 8.2 Instructions 7Page 3 EN 751-2 : 1996 BSI 1997 Introduction This Eu
23、ropean Standard specifies requirements and test methods for non-hardening sealing materials (jointing compounds) for metallic threaded joints. These jointing compounds applied as liquid, gel, paste or tape of non-woven synthetic fibres impregnated with jointing compound paste do at the most only par
24、tly harden or cure. This enables the threaded joint to be easily dismantled with commercial tools at ambient temperatures without damage of the threads. There are three classes of jointing compounds defined by their properties and application range. Class A jointing compounds are suitable for normal
25、 installation purposes for 1st, 2nd and 3rd family gases and heating systems. Class B jointing compounds are normally used in gas appliances and their auxiliary equipment, whereas Class C jointing compounds are for use in LPG storage application. Jointing compounds may be suitable for one or more cl
26、asses. A universally applicable jointing compound may be used for all gas, potable water, and hot water installation. 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 i
27、nformation as to whether the jointing compounds 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.
28、Since the application techniques, sometimes due to different pressure limits and safety requirements, differ from country to country, it is difficult to harmonize the existing national standards and approval requirements for Class A jointing compounds. One particular point relates to the use of seal
29、ant supporting bases (e.g. hemp, flax or synthetic fibres). Whilst these should not be used to fill large gaps between badly fitting threads, in some countries they may be used to ensure that the jointing compound remains in its position on the male thread and is not stripped off during assembly of
30、the joint. It will be up to the manufacturers handling instructions (and the country of use) whether jointing compounds of Class A will be applied with or without such sealant supporting bases. Supporting bases are not used with Classes B and C jointing compounds. The adjustment of prefabricated par
31、ts of an installation requires sometimes the assembled taper/parallel threaded joints to be turned back up to an angle of 45. To ensure that jointing compounds fulfil this requirement in countries where such handling techniques are used, an additional requirement concerning the turn back test has be
32、en included. Such jointing compounds are additionally designated with Rp. 1 Scope This European Standard specifies requirements and test methods for non-hardening sealing materials (hereafter referred to as jointing compounds) suitable for sealing threaded metallic joints such as those specified in
33、ISO 7-1. These jointing compounds are for use in contact with 1st family gases (town gas), 2nd family gases (natural gas) and 3rd family gases (liquefied petroleum gases (LPG) not including LPG in the liquid form) and hot water of heating systems (Class A), in gas appliances and their auxiliary equi
34、pment (Class B) as well as in LPG storage (Class C) according to table 1. Anaerobic jointing compounds are covered by EN 751-1, non-hardening sealing materials in the form of PTFE-tapes are covered by EN 751-3. 2 Normative references This European Standard incorporates by dated or undated reference,
35、 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 amendments to or revisions of any of these publications apply to this European Standard only when incorporated i
36、n it by amendment or revision. For undated references the latest edition of the publication referred to applies. ISO 7-1 Pipe threads where pressure-tight joints are made on the threads Part 1: Dimensions, tolerances and designation ISO 228-1 Pipe threads where pressure-tight joints are not made on
37、the threads Part 1: Dimensions, tolerances and designation EN ISO 2160 Petroleum products Corrosiveness to copper Copper strip test (ISO 2160 : 1985, including Corrigendum 1 : 1993) EN 437 Test gases Test pressures Appliance categories EN 10242 Threaded pipe fittings in malleable cast iron prEN 1025
38、5 Carbon steel tubes suitable for welding or threading prEN 12164 Copper and copper alloys Rod for free machining purposesPage 4 EN 751-2 : 1996 BSI 1997 Table 1. Classification of jointing compounds Class Fluid Temperature range Pressure limit Typical application C bar A, Arp 1) 1st, 2nd, 3rd 2) fa
39、mily gases 220 to 70 5 installation hot water up to 130 7 heating systems B 1st, 2nd, 3rd 2) family gases 220 to 125 0,2 gas appliances C 3rd family gases 220 to 70 20 LPG storage 1) Jointing compounds of Class A where limited turning back of taper/parallel (R/Rp) threaded joints is permitted, are a
40、dditionally marked with Rp. 2) Not including LPG in the liquid phase. 3 Definitions For the purposes of this European Standard the following definitions apply: 3.1 non-hardening jointing compound (referred to hereafter as jointing compound) Sealing material applied as liquid, gel, paste (normally wi
41、thout the addition of sealant supporting bases) or as tape of non-woven synthetic fibres impregnated with jointing compound to the threads. 3.2 sealant supporting bases Materials (e.g. hemp, flax or synthetic fibres) which may be used in some countries to support jointing compound in large threaded
42、joints and ensure that the jointing compound remains in its position on the male thread and is not stripped off during assembly of the joint. 3.3 gas family For further information on types of gases see EN 437. 3.4 batch Any quantity of jointing compound manufactured in a single mix at one time. 4 C
43、lassification of jointing compounds There are three classes of jointing compounds defined by their properties and application range according to table 1. Jointing compounds may be suitable for one or more classes. The class(es) shall be indicated by the manufacturer. 5 Requirements 5.1 Requirements
44、to be met by the jointing compound as received 5.1.1 General The jointing compound shall be homogeneous and free of lumps when tested in accordance with 7.1.1.1. The solids used in its manufacture shall be thoroughly ground. Tapes of non-woven synthetic fibres shall be evenly impregnated or coated w
45、ith jointing compound paste, the mass per area of which when tested in accordance with 7.1.2 of which shall not be lower than 90 % of the value declared by the manufacturer. The jointing compound shall have good wetting properties necessary for adhesion to metallic surfaces when tested in accordance
46、 with 7.2.1.1. 5.1.2 Corrosive properties The jointing compound shall not cause corrosion of aluminium, brass, copper, low carbon steel or zinc surfaces when tested in accordance with 7.1.2. The appearance of copper and brass test strips shall give a classification 3 or less in accordance with EN IS
47、O 2160. 5.1.3 Storage properties The storage life of the jointing compound shall be at least two years in its original unopened container when stored at a temperature less than 25 C, indicated and declared by the manufacturer. 5.2 Requirements to be met by the jointing compound after assembly 5.2.1
48、Sealing properties When tested in accordance with the methods described in 7.2.1 the jointing compound shall not disintegrate or flow out of the joint and shall not permit any leakage when each test assembly is tested in accordance with 7.2.1.2 to 7.2.1.7 in sequence. 5.2.1.1 Soundness When pressuri
49、zed, 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 Class ARp only) After adjusting the test assemblies in accordance with 7.2.1.3 the joints 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 p
