1、BS EN 74-2:2008ICS 91.220NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDCouplers, spigot pinsand baseplates foruse in falsework andscaffoldsPart 2: Special couplers Requirements and test proceduresThis British Standard was published under the authority of the S
2、tandards Policy and Strategy Committee on 30 June 2010 BSI 2010ISBN 978 0 580 68955 0Amendments/corrigenda issued since publicationDate CommentsBS EN 74-2:2008National forewordThis British Standard is the UK implementation of EN 74-2:2008.The UK participation in its preparation was entrusted by Tech
3、nical Committee B/514, Access and support equipment, to Subcommittee B/514/21, Access and working scaffolds and their components (props, tubes and couplers).A list of organizations represented on this committee can be obtained on request to its secretary.The EN 74 series is in three Parts which toge
4、ther replace EN 74:1988. EN 74:1988 was implemented in the UK as BS 1139-2.1:1991 but was withdrawn on the UK implementation of EN 74-1:2005.BS EN 74 Couplers, spigot pins and baseplates for use in falsework and scaffolds consists of the following parts:Part 1 (2005) Couplers for tubes - Requirement
5、s and test proceduresPart 2 (2008) Special couplers - Requirements and test proceduresPart 3 (2007) Plain base plates and spigot pins - Requirements and test The UK Subcommittee is preparing a National Application Document (NAD) to help users in the application of the EN 74 series. Any com-ments on
6、the use of this part, or of the others in the series, or errors that are identified in the text should be notified to the B/514 Committee Secretary, BSI, 389 Chiswick High Road, London W4 4AL so that they can be taken into account in developing the NAD.Additional informationFor other couplers used i
7、n the UK, but not included in BS EN 74-2 or BS EN 74-3, further information may be found in BS 1139-2.2:2009.Textual errorsThe textual errors set out below were discovered when adopting the text of the European standard. They have been reported to the DIN Secretariat in a proposal to amend the text
8、of the European standard.In clause 4, against the symbol Fq, change share to shear.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligatio
9、ns.BS EN 74-2:2008EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 74-2September 2008ICS 91.220English VersionCouplers, spigot pins and baseplates for use in falsework andscaffolds - Part 2: Special couplers - Requirements and testproceduresRaccords, goujons dassemblage et semelles pourtaiements et
10、 chafaudages - Partie 2: Raccords spciaux- Exigences et modes opratoires dessaiKupplungen, Zentrierbolzen und Fuplatten frArbeitsgerste und Traggerste - Spezialkupplungen - Teil2: Anforderungen und PrfverfahrenThis European Standard was approved by CEN on 9 August 2008.CEN members are bound to compl
11、y with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management
12、 Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theoffic
13、ial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Sloven
14、ia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN nation
15、al Members.Ref. No. EN 74-2:2008: EBS EN 74-2:2008EN 74-2:2008 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .6 4 Symbols 8 5 Types and classification of special couplers .9 6 Transmissible internal forces, moments and related stiffnesses 10
16、 6.1 General10 6.2 Half coupler 11 6.3 Sleeve coupler with shear studs (SS)12 6.4 Reduction coupler .12 7 Reference tubes/bar for coupler tests.14 8 General requirements15 8.1 Materials .15 8.2 Design .15 8.3 Manufacturers drawings 17 8.4 Production control.17 9 Tests methods and evaluation of resul
17、ts17 9.1 General17 9.2 Half Couplers18 9.3 Sleeve couplers with shear studs (SS)27 9.4 Reduction couplers .30 10 Designation 30 11 Marking .31 12 Test report 31 13 Assessment31 14 Product Manual31 Annex A (informative) Ongoing production control 33 Annex B (informative) Information about the design
18、of temporary works structures .35 B.1 General35 B.2 Structural design .35 Bibliography 41 BS EN 74-2:2008EN 74-2:2008 (E) 3 Foreword This document (EN 74-2:2008) has been prepared by Technical Committee CEN/TC 53 “Temporary works equipment”, the secretariat of which is held by DIN. This European Sta
19、ndard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2009, and conflicting national standards shall be withdrawn at the latest by March 2009. Attention is drawn to the possibility that some of the elements of thi
20、s document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. The couplers specified in this European Standard are intended for use in temporary works for example scaffolds erected in accordance with EN 12811-1 and fal
21、sework erected in accordance with EN 12812. In accordance with the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, G
22、ermany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 74-2:2008EN 74-2:2008 (E) 4 Introduction This is the second of three parts of a standar
23、d for couplers. EN 74-1 deals with common types of friction couplers. EN 74-2 deals with other less common types of friction couplers and other couplers. EN 74-3 deals with non-adjustable base plates and loose spigot pins. EN 74-2 is not intended to prevent the development of other types of couplers
24、; for example couplers may be manufactured in aluminium or other materials or be designed for use with steel or aluminium tubes with outside diameters different from those specified in this standard. Whilst such couplers cannot conform to this standard, it is recommended that the principles of this
25、standard are considered in their design and assessment. NOTE In the text of this standard, the term “loose spigot” is used instead of the “spigot pin” in the title. BS EN 74-2:2008EN 74-2:2008 (E) 5 1 Scope EN 74-2 specifies: materials; design requirements; specified values for resistances and stiff
26、nesses which a coupler has to achieve under test; test procedures and assessment; for the following special couplers: screw or wedge half couplers, sleeve couplers with shear studs, right angle reduction couplers and swivel reduction couplers. It gives recommendations for on-going production control
27、. These couplers are for use principally in temporary works Each coupler is able to be fixed to at least one side to one 48,3 mm diameter steel or aluminium tube. For the other side of reduction couplers, this standard specifies requirements for the diameter and wall thickness of tubes. For testing,
28、 screw couplers are tightened with a torque of 50 Nm and wedge couplers are tightened with a 500 g hammer until the jarring blow. Other special half couplers such as half couplers attached by riveting, used mainly for members of prefabricated scaffolds, are outside the scope of this European Standar
29、d. NOTE Information on design using special couplers is given in Annex B. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenc
30、ed document (including any amendments) applies. EN 74-1:2005, Couplers, spigot pins and baseplates for use in falsework and scaffolds Part 1: Couplers for tubes Requirements and test procedures EN 1090-2:2008, Execution of steel structures and aluminium structures Part 2: Technical requirements for
31、steel structures EN 12811-1:2003, Temporary works equipment Part 1: Scaffolds Performance requirements and general design EN 12811-2:2004, Temporary works equipment Part 2: Information on materials EN 12811-3:2002, Temporary works equipment Part 3: Load testing EN ISO 898-1:1999, Mechanical properti
32、es of fasteners made of carbon steel and alloy steel Part 1: Bolts, screws and studs (ISO 898-1:1999) BS EN 74-2:2008EN 74-2:2008 (E) 6 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12811-1:2003 and EN 74-1:2005 and the following apply. 3.1 half cou
33、pler (HW, HT) coupler which connects a tube of 48,3 mm diameter to another member either by means of welding (HW) or by means of a welded-in threaded element (HT) NOTE See Figures 1 and 2. Key a profile of welding Figure 1 Half coupler connected by welding (HW) BS EN 74-2:2008EN 74-2:2008 (E) 7 Key
34、a profile of welding t thickness of the head of welded-in threaded element 1 welded-in threaded element (bolt, screw, stud, threaded rod) Figure 2 Half coupler for connection with a welded in threaded element (HT) 3.2 sleeve coupler with shear studs (SS) coupler for connecting 48,3 mm tubes end to e
35、nd by means of a pair of shear studs on each side engaging with two predetermined holes in each tube NOTE See Figure 3. Where required, a manufacturer may specify the use of a loose spigot (not shown on Figure 3). Figure 3 Sleeve coupler with shear studs (SS) BS EN 74-2:2008EN 74-2:2008 (E) 8 3.3 re
36、duction coupler (RR and RS) right angle coupler (RR) or swivel coupler (RS) for connecting two tubes with different diameters of which one tube has a diameter of 48,3 mm NOTE See Figure 4. Figure 4 Reduction coupler as swivel coupler (RS) 4 Symbols For the purpose of this European Standard, the foll
37、owing symbols apply: ck characteristic stiffness of a longitudinal spring; Fsslipping force in kN; Fffailure force in kN; Fppull apart force in kN; Fq share force in kN; MBbending moment in kNm; c(1),MBbending stiffness in kNm/rad; Fs,cspecified value for slipping force in kN; Ff,cspecified value fo
38、r failure force in kN; Fp,cspecified value for pull apart force in kN; BS EN 74-2:2008EN 74-2:2008 (E) 9 MB,cspecified value for bending moment in kNm; c(1),MB,c specified value for bending stiffness in kNm/rad; displacement in millimetres of the transverse tube under load relative to a tube or soli
39、d bar in rotational tests; idisplacement in millimetres of a coupler under load relative to a tube or solid bar; 10indentation in millimetres; P test load in kN; Pindtest load for indentation in kN; Pf,ult ultimate failure force in kN; Pp,ult ultimate pull apart force in kN; Pq,ult ultimate share fo
40、rce in kN; specified angle of rotation of a coupler in degrees. 5 Types and classification of special couplers The types of special couplers are listed in Table 1. The classification is given in Table 2. BS EN 74-2:2008EN 74-2:2008 (E) 10 Table 1 Types of couplers Type Identification Arrangement HW
41、Connection of a tube to a member with a coupler directly welded to the member Half coupler HT Connection of a tube to a member with a coupler which incorporates a welded in threaded element Sleeve coupler with shear studs SS Tubes connected end to end coaxially using holes in the tubes and studs Rig
42、ht angle RR Tube of 48,3 mm diameter connected to a tube of another diameter at a right angle Reduction coupler Swivel RS Tube of 48,3 mm diameter connected to a tube of another diameter at any angle Table 2 Classification of couplers Class Type of coupler A B unclassified Half coupler Sleeve couple
43、r with shear studs Reduction coupler 6 Transmissible internal forces, moments and related stiffnesses 6.1 General In general a connection between two members is able to transmit three internal forces and three moments at right angle. There are related stiffnesses. The connection of a tube to another
44、 member by a threaded element fixed half coupler (HT) or by weldable half coupler (HW) is designed to transmit three forces. Additionally, a Class B half coupler connected by a welded-in threaded element (HT) is designed to transmit one bending moment and a Class B screw weldable half coupler (HW) i
45、s designed to transmit two bending moments as listed in Table 3. A sleeve coupler with shear studs (SS) is designed to transmit one force and one bending moment as listed in Table 4. A right angle reduction coupler (RR) is designed to transmit three forces at right angle in three directions as liste
46、d in Table 5. A swivel reduction coupler (RS) is designed to transmit one force as listed in Table 6. NOTE The influence of the moments resulting from eccentricities of the connection is considered in the test. BS EN 74-2:2008EN 74-2:2008 (E) 11 6.2 Half coupler Table 3 shows the structural paramete
47、rs which are specified. Table 3 Structural parameters for half couplers (HT and HW) Class A B HW Structural parameters (see Figure 5) HW/HT Screw coupler Wedge coupler HT Slipping force Fs Failure force Ff Pull apart force Fp Shear force Fq Bending moment MB,x Force or moment Bending moment MB,y Ben
48、ding stiffness c,MB,x Connection stiffness Bending stiffness c,MB,y Structural parameters are specified in Table 8. Key x,y direction of principal axis Figure 5 Forces and moments for a half coupler BS EN 74-2:2008EN 74-2:2008 (E) 12 6.3 Sleeve coupler with shear studs (SS) Table 4 shows which struc
49、tural parameters are specified. Table 4 Structural parameters for a sleeve coupler with shear studs (SS) Structural parameter See Figure 6 Unclassified Failure force Ff Bending moment MB Structural parameters are specified in Table 8. Figure 6 Forces and moments for a sleeve coupler with shear studs (SS) 6.4 Reduction coupler Tables 5 and 6 show the structural parameters specified. Table 5 Structural parameters for a right angl
