1、I BSI C*17 73 t C i7 : October 1973 UDC 629.7.03 : 621.4-575 : 629.7.064.2 : 621.643.41 5 - - British Standard : Aerospace Series Specification for Coupling dimensions for low pressure air connections for engine starting Foreword This British Standard relates only to features affecting the coupling
2、to an aircraft of the hose unit or adaptor for the delivery of low pressure air for engine starting; it does not specify all the requirements for the connec- tions. The standard conforms to the requirements of International Standard IS0 . . . .*, Connections for starting aircraft engines by air of t
3、he International Organization for Standardization, prepared at the request of the International Air Transport Association as one of a series of standards for aircraft ground servicing connections suitable for adoption on an international basis. NOTE. A table is given in Appendix A to provide a ready
4、 means of calculating the approximate metric equivalents of the specitied dimensions. More accurate conversions should be based on the tables in BS 350, Conversion factors and tables , or in BS 2856, Precise conversion of inch and metric sizes on engineering drawings , as appropriate. * In course of
5、 preparation. Specification 1. Scope This British Standard specifies the basic dimensional and installational requirements for connections on aircraft to ensure coupling to ground equipment supplying low pressure air for engine starting. 2. Dimensions 2.1 The dimensions of the connection shall confo
6、rm to the basic requirements shown in Fig. 1. 2.2 The clearance allowed in the aircraft structure surrounding the connection for the introduction and handling of the ground equipment connector shall be as Indicated in Fig. 2. The clearance space may be orientated about the axis of the aircraft conne
7、ction to any desired position. Gr 3 British Standards Institution . 2 Park Street . London W1 A 2BS Telephone O1 -629 9000 Telex 266933 C 17 : 1973 47: O 15 - - U C C oc b O I x 8 _ - 2.625- - -e -j -0.375 f 4 A-0.200 I 30“: O“ 30 / R 0.040 R 0.035: 0.005 .4- Minimum length to ensure coupling connec
8、tion - increase length to provide clearance when bolted flanges are used -i- 0.060 rt- Design optional beyond this point ,OS=ef. I .O03 point 3.300: 0.003 gaurie die. .- 1 Detail X - Showing gauge points NOTE 1. Unless otherwise specified, tolerances shall be f 0.010. NOTE 2. The 3.207, 3.100, 3.344
9、, 3.400 and 3.461 diameters shall be concentric within 0.002 total indicator reading. NOTE 3. The inside diameter shall be concentric with the above diameters within 0.010 total indicator reading. NOTE 4. Unless otherwise specified, ail corner radii shall be 0.020. All dimensions are in inches. Fig.
10、 i. Coupling dimensions for aircraft low pressure air connection for engine starting 2 8.25 rnax. - t i I I T t I I I + 6 min. i I j i i t I l l i All dimensions are in inches. Third angle projection. P.5.5 min. ! ! 7 min. I Fig. 2. Minimum clearance space for ground equipment connector 3 ,- 1 BSI C
11、*17 73 m Lb24669 0095373 A C 17 : 1973 Appendix A Table for conversion of inches to approximate millimetre equivalents 25.4 50.8 76.2 101.6 127.0 152.4 177.8 203.2 228.6 254.0 Examples of use of Table: 1.75 in = 25.4 + 17.78 + 1.27 = 44.5 mm 0.82 in = 20.32 + 0.508 = 20.8 mm. These examples give ari
12、thmetic conversions. For conversions to the required accuracy to ensure dimensional interchangeability, use BS 2856, Precise conversion of inch and metric sizes on engineering drawings . This British Standard, having been approved by the Aerospace Industry Standards Committee, was published under th
13、e authority of the Executive Board on 31 October, 1973 0 British Standards Institution, 1973 ISBN: O 580 07848 5 Copyright Users of British Standards are reminded that copyright subsists in all BSI publications. No part of this publication may be reproduced in any form without the prior permission i
14、n writing of BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols and size, type or grade designations. Enquiries should be addressed to the BSI Secretariat. Contract requirements Attention is drawn to the fact that this British S
15、tandard does not purport to include all the necessary provisions of a contract. Revision of British Standards British Standards are revised, when necessary, by the issue either of amendment slips or of revised editions, It is important that users of British Standards should ascertain that they are in possession of the latest amendments or editions. The following BSI references relate to the work on this standard: Committee reference ACE/14 Draft for approval 72/38014. 4
