1、British Standard M 62 :I987 IS0 7661-1984 UDC 629.7.063 : 621.643.4.066 British Standards Institution. No part of this publication may be photocopied or otherwise reproduced without the prior permission in writing of BSI British Standard Aerospace Series : Specification for Design and qualification
2、testing of clamp blocks for fluid system tube lines having axial alignment. Metric series IS0 title: Aerospace- Fluid systems- Clamp blocks for tube lines having axial alignment- Design standard and qualification testing - Metric series Srie arospatiale. Conception et essais de qualification des pei
3、gnes supports de tuyauteries alignement axial des systmes de fluides - Srie mtrique - Spcifications Luft- und Raumfahrt-Reihe. Fluidische Systeme; Halterungsschellen in Blockform fr parallele Montage von Rohren; Konstruktion, Qualittsprfung; metrische Reihe 0 Contents National foreword Committees re
4、sponsible Specification 1 2 References 3 Definitions 4 Classification of clamp blocks 5 Dimensions of clamp blocks 6 Temperature conditions 7 Qualification tests 7.1 Electrical tests (for clamp blocks with electrical grounding) 7.2 Mechanical tests 7.3 Climatic tests 7.4 Flame resistance test Scope
5、and field of application O Page 2 Back cover 3 3 3 5 5 6 6 6 6 8 8 Page Tables 1 Maximum height o. the clamp block 2 Nominal radius of the clamp block 3 Width of removable parts 5 5 6 Figures 1 Monobloc clamp block 4 2 Modular clamp block (without insert) 4 3 Clamp block with intermediate mounting h
6、ole 5 4 Apparatus for sliding test 7 10 5 Schematic representation showing the position of the clamp block with respect to the flame O British Standards Institution h - s- -z BSI M*b2 87 Lb24bb9 00795L2 7 9 .t - - - British Standard M 62 :I987 National foreword Compliance with a British Standard doe
7、s not of itself confer immunity from legal obligations. This British Standard has been published under the direction of the Aerospace Standards Committee. It is identical with IS0 7661-1984 Aerospace - Fluid systems - Clamp blocks for tube lines having axial alignment - Design standard and qualifica
8、tion testing - Metric series, published by the Internationai Organization for Standardization (ISO). IS0 7661 was produced as a result of international discussion in which the UK took an active part. Terminology and conventions. The text of the international standard has been approved as suitable fo
9、r publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use a fu
10、ll point on the baseline as the decimal marker. Wherever the words International Standard appear, referring to this standard, they should be read as British Standard. I 2 British Standard :M 62 : 1987 1 Scope and field of application O - This International Standard gives definitions for clamp blocks
11、 for tube lines having axial alignment, with or without electrical grounding, designed for a range of tube outside diameters from 4 to 32 mm selected from IS0 2964, and it lays down the dimensions of clamp blocks and specifies the test methods for qualification testing. These clamp blocks permit the
12、 fastening of tubes, used for dif- ferent purposes in fluid systems. 2 References ISO/TR 2685, Aircraft - Environmental conditions and test procedures for airborne equipment - Resistance to fire in designated fire zones. IS0 2964, Aircraft - Tubing outside diameters andthicknesses - Metric dimension
13、s. IS0 5855, Aerospace construction - MJ threads - Part 1 : Basic profile. Part 2 : Dimensions for bolts and nuts. IS0 6771 , Aerospace construction - Fluid systems and com- ponents - Pressure and temperature classifications. IS0 7137, Aircraft - Environmental conditions and test pro- cedures for ai
14、rborne equipmenf.1) 3 Definitions 3.1 axial alignment :A clamp is said to have an “axial align- ment” when the axes of supported tubings are located in the same plane. 3.2 clamp block for tubing : A device used on aerospace vehicles for fixing tubings the dimensions of which may be dif- ferent and w
15、hich are constituted from materials that may be different. 3.2.1 -monobloc clamp block : A clamp block for tubing (3.2) consisting of two monobloc parts. (See figure 1.) 3i2.2 modular clamp block :A clamp block for tubing (3.2) consisting of removable parts (3.41, with or without inserts) (3.5). (Se
16、e figure 2.) 3.3 clamp block with intermediate mounting hole : A monobloc clamp block (3.2.11 or a modular clamp block (3.2.21, having one or more intermediate mounting hole(s). (See figure 3.) 1) Endorsement, in part, of the publication EUROCAE ED-14AIRTCA DO-160A (a document published jointly by t
17、he European Organisation for Civil Aviation Electronics and the Radio Technical Commission for Aeronautics). 3 -s BSI M*b2 e7-m Lb24bb9 0099514 O m .- British Standard M 62 :I987 5 -!- -+i- 8 E I ZJ 8 i? I o C - C Boltspacing f 0,125 -I Dimensions in millimetres Y-Y I SeeISO5855. Figure 1 - Monobloc
18、 clamp block Dimensions in millimetres Boltspacing f 0,125 See ISO5855. Y-Y th of tube support Figure 2 - Modular clamp block (without insert) 4 - - BSI M*b2 87 E Lb24bb9 0099515 2 British Standard -M 62 : 1987 A B C Figure 3 - Clamp block with intermediate mounting hole - 27 27 27 27 27 27 35 35 35
19、 35 35 35 35 35 35 483 483 48.5 48,5 48,s 483 483 483 483 483 483 3.4 removable part: A part of a modular clamp block (3.2.2) which ensures a standardized clearance between two adjacent tubings. Class B : Tube outside diameters from 4 to 20 mm Class C : Tube outside diameters from 4 to 32 mm - OQ No
20、minal radius, R 2 Tube outside diameter 3.5 insert : A part that can be assembled between two removable parts (3.4) in order to obtain the required centre-to- centre distance, standardized or not, between tubes. o5 o6 08 10 12 14 16 20 25 32 23 3 4 5 6 7 8 10 12,5 16 4 Classification of clamp blocks
21、 The clamp blocks are divided into three classes, A, B and C, each corresponding to a range of tube outside diameters and to a maximum clamp block height (see table 11, as follows : Class A : Tube outside diameters from 4 to 12 mm 5 Dimensions of clamp blocks 5.1 Maximum height Table 1 gives, for ea
22、ch clamp block class and for each tube out- side diameter, the maximum height, H, of the clamp block (see figures 1 and 2). 5.2 Nominal radius Table 2 gives, for each tube outside diameter, the nominal radius R, of the clamp block (see figures 1 and 2). Table 1 - Maximum height of the clamp block Di
23、mensions io millimetres Tube outside diameter 041 05 I 061 081 10 I 12 I 14 I 16 I 20 I 25 I 32 Maximum heiaht of the clamr, block, H Identification class of the clamp block Table 2 - Nominal radius of the clamp block 5 Tube outside Width of removable parts, L Model 1 Model 2 O -0,l diameter - o4 O
24、L2 -0.1 9 12 14 16 15 17 17 19 19 21 20 25 23 25 28 30 32 35 37 British Standard M 62 : 1987 5.3 Width of removable parts Type 111 : -55 to + 200 OC Two models of removable parts for modular clamp blocks are standardized, as follows : 7 Qualification tests - tubes; model 1 allows a clearance of.3 mm
25、 between adjacent 7.1 electrical grounding) Electrical tests (for clamp blocks with - tubes. model 2 allows a clearance of 5 mm between adjacent 7.1.1 Measurement of the ele.ctrical contact resistance NOTE - Model 2 may be composed of a removable part and an insert. NOTE - This measurement shall be
26、carried out before and after the mechanical tests (7.2) and climatic tests (7.3). Table 3 gives, for each tube outside diameter, the width L (LI for model 1 and Lpfor model 2) of removable parts for modular clamp blocks. Measure the potential drop between one of the fastening screws of the clamp blo
27、ck and each one of the test tubes, using a direct current power source (1 to 4 A) and a millivoltmeter. Before carrying out any test, the contact resistance shall be less than or equal to 150 mQ. In order to obtain a contact resistance with a lower value, a different electrical continuitv procedure
28、shall be considered. 7.2 Mechanical tests I I I I I o6 I 9 I 11 I 7.2.1 Sliding test under temperature I I I I o8 I 11 I 13 I NOTE - The following test does not apply in the case of clamp blocks where there is no possibility of retention on the tubes they support. I 10 I 13 I 15 I 7.2.1.1 Samples Th
29、ree samples shall be provided for this test and shall consist of clamp blocks for three parallel tubes, of length 50 mm, of the same material (aluminium alloy, stainless steel or titanium) and with the same diameter : 4, 12 and 20 mm respectively. 5.4 Clamp block bolt spacing 7.2.1.2 Test apparatus
30、A suitable device, in conformity with figure 4, shall allow the - sliding of the tubing in a clamp block with a displacement of 0 6 mm (.e. b) the electrical contact resistance : see 7.1.1. 7.2.1.5 Final measurements After dismantling each tube from the test device, take the following final measurem
31、ents at room temperature : a) the sliding force for the tubes; b) the electrical contact resistance (see 7.1.1) : the measurement of the electrical resistance shall be made before the tubes are dismantled; c) examination and measurement of the tube and clamp contact areas for grooves and wear marks,
32、 after the clamp block has been dismantled. 0 7.2.1.6 Acceptance criteria After the test, the following requirements shall be met : a) the sliding force for each tube shall remain greater than 5 N; b) the electrical contact resistance shall remain less than 150 mQ: c) the wear marks on the tubes aft
33、er slide testing shall not exceed the following values : - stainless steel tubes : 15 pm - titanium tubes : 15 pm d) whatever the material, the allowable wear on the diameter of the tubes shall remain lower than or equal to the following values : - tube outside diameters from 4 to 10 mm : wear less
34、than or equal to O,5 mm relative to the nominal diameter - tube outside diameters from 12 to 32 mm : wear less than or equal to 0,08 mm relative to the nominal diameter 7.2.2 Sliding test combined with contamination 7.2.2.1 Samples Three samples shall be provided for this test and shall consist of c
35、lamp blocks for three parallel tubes, of length 50 mm, of the same material (aluminium alloy, stainless steel or titanium) and with the same diameter : 4, 12 and 20 mm respectively. 7.2.2.2 Aim of the test This sliding test is intended to determine the consequences on the behaviour of a clamp block
36、and of its tube when exposed to certain fluids used in aerospace vehicles, in a sand- and dust- laden atmosphere with a definite saturation concentration. The fluids to be considered for this test shall be as follows : - fuel; - phosphate ester based hydraulic fluid; - ester silicate; - aluminium al
37、loy tubes : 40 pm - de-icing fluid; 7 British Standard M62: 1987 - cleaning fluid; - fire extinguishing liquid. 7.2.2.3 Test method Assemble the clamp bbck and tubes as laid down in 7.2.1. Coat all of the external surfaces of the clamp block assembly, by brushing or spraying with the fluid under con
38、sideration. In- stall the clamp block assembly in a test chamber for the operating test in a sand- and dust-contaminated atmosphere. Submit the clamp block assembly to a sand and dust test in ac- cordance with IS0 7137. 7.2.2.4 Acceptance criteria After the test, the following requirements shall be
39、met : a) the sliding force for each tube shall remain greater than 5 N; b) the electrical contact resistance.shal1 remain less than 150 mQ c) the depth of the wear marks on the tubes shall not ex- ceed 5 % of the tube thickness for stainless steel and titanium tubes and it shall not exceed 10 % of t
40、he tube thickness for light alloy tubes; d) allowable wear on the tubes : the reduction of the tube thickness shall remain less than 10 % of the minimum thickness determined during initial checks. d) the depth of the wear marks on the tubes shall not .- exceed 5 % of the tube thickness for stainless
41、 steel and a titanium tubes and it shall not exceed 10 % of the tube thickness for light alloy tubes; e) allowable wear on the tubes : the reduction of the tube thickness shall remain less than 10 % of the minimum thickness determined during initial checks. 7.3 Climatic tests NOTE - The climatic tes
42、ts described in 7.3.1 to 7.3.3 are static tests. 7.3.1 Low temperature test Submit the clamp block assembly to a low temperature test (at the minimum temperature specified in clause 6) in accordance with IS0 7137. 7.3.2 High temperature test Submit the clamp block assembly to a. high temperature tes
43、t (at accordance with IS0 7137. the maximum service temperature specified in clause 6) in * 7.3.3 Salt spray test NOTE - When the materials constituting the clamp blocks have previously been found satisfactory in salt spray tests meeting the re- quirements of IS0 7137, the clamp block may be qualifi
44、ed by analogy. 7.3.3.1 Initial measurements .I . Measure the electrical contact resistance see 7.1 .I). 7.3.3.2 Test 7.2.3 Vibration test Submit the clamp block provided for this test to a salt spray test in accordance with IS0 7137. 7.2.3.1 Test method Rigidly fasten onto the test apparatus an asse
45、mbly comprising two clamp blocks, spaced 50 cm apart, fitted with three tubes, of length 1 m, with the same diameter and of the same material (aluminium alloy, stainless steel or titanium). Submit this assembly to a severe vibration test in accordance with IS0 7137 (see curve in figure 8-6 in sub-cl
46、ause 8.4 of the publication EUROCAE ED-l4A/RTCA DO-160 A). 7.2.3.2 Acceptance criteria After the test, the following requirements shall be met : a) there shall be no damage of the clamp block (cracking, failure or significant wear) nor loosening of the screws; b) the sliding force for each tubsshall
47、 remain greater than 5 N; c) the electrical contact resistance shall remain less than 150 mQ 7.3.3.3 Final measurements Check the appearance and measure the electrical contact * resistance see 7.1.1). 7.3.3.4 Acceptance criteria After the condition of the tube and clamp block assembly has been check
48、ed, the following requirements shall be met : a) corrosion shall not affect the appearance of any one of the clamp block components; b) the electrical contact resistance shall be less than 150 mQ. 7.4 Flame resistance test NOTE - If the clamp block is to be used in a fire zone and if the specific conditions of its use require fite resistance capability, this clamp block shall be submitted to the same fire test as the tubes which are to be supported see ISO/TR 2685). 8
