1、BS EN 3908:2017Aerospace series Nipples,lubricating, axial type, incorrosion resisting steel,passivatedBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN 3908:2017 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 3908:2017. The
2、 UK participation in its preparation was entrusted to TechnicalCommittee ACE/12, Aerospace fasteners and fastening systems. A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a
3、 contract. Users are responsible for its correct application. The British Standards Institution 2017.Published by BSI Standards Limited 2017ISBN 978 0 580 92978 6 ICS 49.035 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the
4、 authority of the Standards Policy and Strategy Committee on 31 January 2017.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS EN 3908:2017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 3908 January 2017 ICS 49.035 English Version Aerospace series - Nipples, lubricat
5、ing, axial type, in corrosion resisting steel, passivated Srie arospatiale - Graisseurs accrochage axial, en acier rsistant la corrosion, passivs Luft- und Raumfahrt - Kegel-Schmiernippel, aus korrosionsbestndigem Stahl, passiviert This European Standard was approved by CEN on 11 March 2016. CEN mem
6、bers 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 national standards may be obtained on applicat
7、ion to the CEN-CENELEC Management 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 translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Manage
8、ment Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
9、 Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue
10、 Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 3908:2017 EBS EN 3908:2017EN 3908:2017 (E) 2 Contents Page European foreword . 3 1 Scope 4 2 Normative references 4 3 Required characteristics 5 4 Des
11、ignation 7 5 Marking . 8 6 Technical specification 8 7 Requirements and test methods 8 Annex A (normative) Installation requirements . 12 A.1 Space requirements 12 A.2 Installation thread requirement 12 BS EN 3908:2017EN 3908:2017 (E) 3 European foreword This document (EN 3908:2017) has been prepare
12、d by the Aerospace and Defence Industries Association of Europe - Standardization (ASD-STAN). After enquiries and votes carried out in accordance with the rules of this Association, this European Standard has received the approval of the National Associations and the Official Services of the member
13、countries of ASD, prior to its presentation to CEN. 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 2017, and conflicting national standards shall be withdrawn at the latest by July 2017. Att
14、ention is drawn to the possibility that some of the elements of this 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. According to the CEN-CENELEC Internal Regulations, the national standards organizations o
15、f the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Net
16、herlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 3908:2017EN 3908:2017 (E) 4 1 Scope This European Standard specifies the required characteristics and the tests for lubricating nipples of the axial type, in corr
17、osion resisting steel, passivated. Annex A (normative) states the clearance space requirements for the coupling and uncoupling of the lubricating gun and the maximum permissible diameter of the lubricating gun barrel, together with installation thread requirements. Lubricating nipples according to t
18、his European Standard are intended for use in aerospace assemblies, where regular lubrication of moving parts is required. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references,
19、 only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 2424, Aerospace series Marking of aerospace products EN 2516, Aerospace series Passivation of corrosion resisting steels and decontamination of nickel base al
20、loys EN 9100, Quality Management Systems Requirements for Aviation, Space and Defense Organizations ISO 68 (all parts), ISO general purpose screw threads Basic profile IS0 413, Aircraft Heads of lubricating nipples ISO 965-2, ISO general purpose metric screw threads Tolerances Part 2: Limits of size
21、s for general purpose external and internal screw threads Medium quality ISO 2859-1, Sampling procedures for inspection by attributes Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection ISO 6507-1, Metallic materials Vickers hardness test Part 1: Test method
22、STANAG 1135:2008, Interchangeability of fuels, lubricants and associated products used by the armed forces of the North Atlantic Treaty Nations 1)1) Published by: North Atlantic Treaty Organization (NATO), Military Agency for Standardization (MAS), 1110 Brussels, Belgium. BS EN 3908:2017EN 3908:2017
23、 (E) 5 3 Required characteristics 3.1 Configuration Dimensions Masses The envelope dimensions for the nipple head are shown in Figure 1, detail “Z“ and are in accordance with ISO 413. The tip design of the nipple (face with the sealing ball) is left at the manufacturers option provided the profile r
24、emains within the envelope dimensions shown in figure 1 and the requirements of Clause 7 are met. The dimensions apply after surface treatment. A check valve (composed of a spring and ball) shall be located at the surface of the nipple to prevent the ingress of foreign matter into the nipple tip. Ot
25、her internal design shall be at the manufacturers discretion provided the nipples meet the requirements specified in Clause 7. 3.2 Surface roughness Ra= 6,3 m unless otherwise specified. The values apply prior to surface treatment. The surface roughness of the thread will be as achieved by normal me
26、thods of manufacture. 3.3 Materials Austenitic chromium-nickel steel; ultimate strength min. 550 MPa. See also 7.6.2. The nipple head surface shall be case hardened to a depth of 0,08 mm to 0,13 mm to give a minimum hardness value of HV 533 (52 HRC). The nipple body shall withstand a tightening torq
27、ue of 9 Nm without strain. Material and surface treatment for the internal parts of the nipple shall be at the manufacturers option. 3.4 Surface treatment EN 2516, process appropriate to the material BS EN 3908:2017EN 3908:2017 (E) 6 Dimensions in millimetres Mass: max. 3 g/piece Form A (code 01) Ma
28、ss: max. 10 g/piece Form B (code 02) Mass: max. 11 g/piece Form C (code 03) Key 1 At manufacturers option 2 Marking area (for forms A, B and C) 3 Detail X: see Figure 2. 4 Across flats 5 Maximum contour (broken line) 6 Minimum contour (continuous line) a Shape optional Figure 1 BS EN 3908:2017EN 390
29、8:2017 (E) 7 3.5 Thread The thread shall be tapered as shown in Figure 2 and conform with ISO 68 and ISO 965-2. Dimensions in millimetres Key 1 1 to 2 Figure 2 Detail X of Figure 1 4 Designation EXAMPLE Description block NIPPLE Identity block EN3908-01 Number of this standard Form code of nipple (se
30、e Figure 1) NOTE If necessary, the code I9005 shall be placed between the description block and the identity block. BS EN 3908:2017EN 3908:2017 (E) 8 5 Marking EN 2424, style F for products (see Figure 1) and style G for each packing 6 Technical specification The lubricating nipples shall meet the r
31、equirements of this European Standard. For quality assurance requirements, see EN 9100. 7 Requirements and test methods Acceptance tests shall be carried out for each inspection lot. Samples shall be selected from the inspection lots in accordance with the requirements of ISO 2859-1. For non-destruc
32、tive tests “General inspection level“ II and an AQL of 1,0 for sample size (n) shall be used (see Table 1). For destructive tests “Special level“ S4 and an AQL of 1,5 for sample size (n) shall be used (see Table 2). NOTE The requirements for “continuation of inspection“, “switching procedures“ and “
33、discontinuation of inspection“ shall be in accordance with 9.2, 9.3 and 9.4 of ISO 2859-1. Table 1 Batch size (pieces) n AC 90 13 0 91 to 150 20 1 151 to 280 32 1 281 to 500 50 1 501 to 1 200 80 2 1 201 to 3 200 125 3 3 201 to 10 000 200 5 Table 2 Batch size (pieces) n AC 500 8 0 501 to 10 000 32 1
34、BS EN 3908:2017EN 3908:2017 (E) 9 7.1 Materials and surface treatment The manufacturer shall provide a test certificate proving that all materials and surface treatments comply with the requirements of 3.3 and 3.4 and shall also show that the quality has been maintained throughout all stages of nipp
35、le manufacture. 7.2 Dimensions Components shall be inspected to verify that they conform to the relevant requirements of 3.1. Sample size: see Table 1. The thread test and the verification of the absence of burrs are not included (see 7.3 or 7.6.1). 7.3 Absence of burrs The nipple shall be submitted
36、 to a 100 % inspection to check the absence of burrs. 7.4 Marking Marking shall comply with the requirements of Clause 5. Sample size: see Table 1. 7.5 Hardness 7.5.1 The hardness test (Vickers) in accordance with ISO 6507-1 shall be carried out on the across flats of the lubricating nipple. Sample
37、size: see Table 2. 7.5.2 A minimum of five components shall be selected from those tested according to 7.5.1. 7.5.3 They shall be fractured and the case depth shall be as specified in 3.3. 7.6 Thread inspection and strength test For the purpose of these tests a parallel internal thread M61-6H shall
38、be cut into a steel plate (strength 900 MPa). There shall be no chamfer at the entrance of the thread. BS EN 3908:2017EN 3908:2017 (E) 10 7.6.1 Thread test The thread shall be submitted to a 100 % inspection. It shall be possible to engage each nipple manually as deep as indicated in Figure 3. Dimen
39、sions in millimetres Key 1 1 to 2 2 Test plate, see 7.6. Figure 3 7.6.2 Strength test The lubricating nipples shall withstand the tightening torque requested in 3.3 when installed in a test plate to the requirements of 7.6. When removed there shall be no sign of strain on the nipple body and there s
40、hall be no substantial change in the tapered nipple thread. Sample size: see Table 1. 7.7 Performance check 7.7.1 A production check, of a simple mechanical nature not involving the use of grease, shall be carried out on each assembled nipple to ensure that the check valve will open and seat satisfa
41、ctorily. 7.7.2 Ten nipples of each form, shall be shown to meet the design performance requirements laid down in Table 3 using a lubricant complying with NATO G-354 (see STANAG 1135). The test block shall have a minimum capacity of 10 ml (a suitable form of test block is depicted in Figure 4). Table
42、 3 Test Requirements and limitations Admit lubricant at a pressure of 7 MPa with the coupled gun held at an angle of 10 to the nipple axis. No lubricant leakage is permitted between the gun and the nipple head. Opening of the nipple valve Between 1 MPa and 3,5 MPa Leakage at sustained pressure of 35
43、 MPa 2 ml / min max. BS EN 3908:2017EN 3908:2017 (E) 11 Key 1 Minimum capacity of grease duct: 10 ml 2 Vent-screw Figure 4 Test block BS EN 3908:2017EN 3908:2017 (E) 12 Annex A (normative) Installation requirements A.1 Space requirements Sufficient clearance space shall be provided around the lubric
44、ating nipple to allow the coupling and uncoupling of the lubricating gun as shown in Figure A.1. It shall be noted that, in uncoupling, the gun has to be tilted up to 25 in any radial direction. Dimensions in millimetres Key 1 Uncoupling angle Figure A.1 A.2 Installation thread requirement The insta
45、llation hole shall have a parallel thread conforming to M61-6H to the requirements of ISO 68 and ISO 965-2. This page deliberately left blankBSI is the national body responsible for preparing British Standards and other standards-related publications, information and services.BSI is incorporated by
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