1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2007 SAE International All rights reserved. No part of this publication m
3、ay be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org J2494-3 REV. AUG2007 SURFACE VEHICLE STANDARD Issued 2002-07 Revised 2007-08 Superseding J2494-3 JUL2002 Performance Requirements for SAE J844 Non-Metallic Air Brake Tubing and Push to Connect Fitting Assemblies Used
5、 in Vehicular Air Brake Systems RATIONALE The modifications to this document are to harmonize the requirements of SAE J1131 and SAE J2494-3 where applicable. 1. SCOPE This SAE Standard is intended to establish uniform performance criteria and methods of testing push to connect tube fittings, with SA
6、E J844 air brake tubing as used in vehicular air brake systems. The specific tests and performance criteria applicable to the tubing are set forth in SAE J844. The test values contained in this performance standard are for test purposes only. For environmental and usage limitations, see SAE J844. 1.
7、1 General Requirements a. Test temperature shall use 3 C as the test tolerance range. b. Ambient temperature shall be 24 C. c. All test times are minimum times unless otherwise specified. d. Dry Air shall be a minimum of 50 C dew point. e. Tubing shall be cut square at 90 degrees 7 degrees. f. Preco
8、ndition all test specimens at 700 kPa 70 kPa for 30 s without any leakage. g. New specimens shall be used for all tests. 2. REFERENCES 2.1 Applicable Publications The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue
9、 of SAE publications shall apply. SAE J2494-3 Revised AUG2007 - 2 - 2.1.1 SAE Publications Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J844 Nonmetallic Air Brake System Tubing SAE J20
10、24 Contaminants for Testing Air Brake Components and Auxiliary Pneumatic Devices SAE J2494-1 Dimensional Specifications for Metallic Body Push-to-Connect Fittings Used on a Vehicular Air Brake System SAE J2494-2 Dimensional Specifications for Non-Metallic Body Push-to-Connect Fittings Used on a Vehi
11、cular Air Brake System SAE J2494-4 Cartridge Cavity SAE HS J806 SAE Oil Filter Procedure 2.1.2 ASTM Publications Available from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM B 117 Salt Spray (Fog) Testing ASTM D 4329 Standard Practice for Fluore
12、scent UV Exposure of Plastics ASTM G 53 Practice for Operating Light- and Water-Exposure Apparatus (Fluorescent UV-Condensation Type) for Exposure on Nonmetallic Materials ASTM G 151 Standard Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources AS
13、TM G 154 Practice for Operating Fluorescent Light Apparatus for UV Exposure of Nonmetallic Materials 2.1.3 Federal Publication Available from the Superintendent of Documents, U.S. Government Printing Office, Mail Stop: SSOP, Washington, DC 20402-9320. DOT FMVSS 571.106 (49CFR 571.106) Brake Hoses 3.
14、 REQUIREMENTS FOR METALLIC AND NON-METALLIC FITTINGS 3.1 Tensile Tests (15 specimens) 3.1.1 Description Both hot and cold tensile tests shall be conducted with different unaged assemblies (fittings attached within 30 days of test date). Tests consist of subjecting the assembly to increasing tensile
15、load in a suitable testing machine until the specified force value or elongation percentage has been obtained. SAE J2494-3 Revised AUG2007 - 3 - 3.1.2 Apparatus A tensile test machine with suitable indicating device shall be used for the tensile test. The fixtures for holding the test specimens shal
16、l be arranged so the tubing and fittings have a straight centerline corresponding to the direction of the machine pull. The lower part of the fixture shall be equipped with a container of sufficient dimensions to submerge the required length of tubing in water. A means of heating the water to boilin
17、g shall be provided. A cover shall not be used on the container. This allows the steam to dissipate into the environment. If a fan is used in this test, then take precautions to direct the air away from the test specimen. 3.1.3 Test Specimens The tubing specimens (a minimum of 15) shall be obtained
18、from current production stock and cut to a length sufficient to obtain 150 mm 6 mm of tubing between end fittings after assembly. Assemble fittings to the tubing using the manufacturers recommendations. 3.1.4 Procedure (15 specimens) 3.1.4.1 High Temperature Tensile Test (5 specimens) Place the test
19、 specimen in the tensile machine with the lower fitting and 102 mm (+6/0 mm) of tubing submerged below the surface of the boiling distilled water such that the outside diameter is exposed to the water. Continue boiling for 5 min (+0.5/0 min). Apply load at a rate of pull of 25 mm/min. 3.1.4.2 Condit
20、ioned Tensile Test (5 specimens) Condition test specimen at 40 C for 30 min (+0.5/0 min), normalize at ambient temperature then submerge in boiling water for 15 min. Repeat for a total of four complete cycles. Allow the test specimen to normalize at room temperature for 30 min. Conduct the tensile t
21、est within 30 min after the normalizing period while at ambient temperature of 24 C. Apply load at a rate of 25 mm/min. 3.1.4.3 Water Absorption and Tensile Test (5 specimens) After immersion in distilled water at ambient temperature for 70 h, conduct tensile test on the specimen by applying a load
22、at the rate of 25 mm/min. The tube assembly shall withstand without separation of the tube and end fittings a tensile pull as listed in Table 1. 3.1.5 Acceptance Criteria Requirements Each specimen shall elongate 50% (min), that is 150 mm increased to 225 mm, or shall withstand the load listed in Ta
23、ble 1 without causing separation from the fitting. TABLE 1 - TENSILE REQUIREMENTS Nominal Tubing OD (in) Tensile Load (Newtons) 5/32 225 3/16 225 1/4 225 5/16 335 3/8 670 1/2 900 5/8 1450 3/4 1560 SAE J2494-3 Revised AUG2007 - 4 - 3.2 Air Leakage (5 specimens) 3.2.1 Description This test is designed
24、 to evaluate the effects of high and low system pressures on the fitting assembly at high and low temperatures. 3.2.2 Apparatus The equipment must be capable of controlling the ambient air temperature between 40 C and 104 C while applying 1035 kPa or 70 kPa dry air to the test lines. A mass flow met
25、er capable of determining air leakage shall be provided. 3.2.3 Test Specimens Cut tubing specimens to a length sufficient to obtain 460 mm between fittings after assembly. Assemble identical fittings to the tubing using the manufacturers recommendations. 3.2.4 Procedure Place both ends of the test s
26、pecimens in temperature cycling cabinet and connect to a pressure source capable of 70 kPa 7 kPa and 1035 kPa 70 kPa pneumatic pressure. Pressure 4 c/h, alternating between 70 kPa 7 kPa and 1035 kPa 70 kPa. Subject the test specimens while under pressure to ambient temperature for 2 h, 104 C for 12
27、h, ambient temperature for 2 h, 40 C for 2 h, and ambient temperature again for 2 h in the order listed. See Table 2 and Figure 1. TABLE 2 - AIR LEAKAGE TEST CONDITIONS Time (hours) Pressure (kPa) Temperature (C) 2 1035 24 14 1035 104 16 1035 24 18 1035 40 20 1035 24 FIGURE 1 - AIR LEAKAGE TEST CYCL
28、E CHART SAE J2494-3 Revised AUG2007 - 5 - 3.2.5 Acceptance Criteria After the pressure in the assembly is allowed to stabilize, the test specimens are considered a failure if the average leakage per fitting on any assembly at specified test conditions in Table 2 exceeds the amounts listed in Table 3
29、. TABLE 3 - LEAKAGE TEST REQUIREMENTS Test Temperature (C)Maximum Leakage (Standard Cubic Centimeters/Minute) 104 3 24 5 40 7 3.3 Vibration Test (5 specimens) 3.3.1 Description This test is designed to evaluate the effects of vibration on a tube and fitting assembly under varying internal pressures
30、and ambient temperatures. Leakage rate is used to gauge acceptability. 3.3.2 Apparatus Equipment capable of vibrating one end of the test specimen at 600 Hz through 12 mm displacement in a plane perpendicular to the tube while the other end is held rigid. The distance between the static and vibratin
31、g head is to be such, that when the assembly is displaced 12 mm, no parallel pull to the longitudinal axis of the assembly will occur. The equipment must be capable of automatically adjusting the system pressure to compensate for fluctuating temperatures between 40 C and 104 C and associated air pre
32、ssure of 830 kPa (70 kPa) dry air during the test process. A mass flow meter capable of determining air leakage shall be provided. 3.3.3 Test Specimens Allowing 12 mm slack, cut a minimum of 5 tubing specimens to a length sufficient to obtain 460 mm between fittings after assembly. Assemble identica
33、l fittings to the tubing using the manufacturers recommendations. 3.3.4 Procedure Allowing 12 mm slack, mount the lines straight in the vibration machine. Oscillate one end of the lines at 600 cycles/minute (20 cpm) through a total stroke of 12 mm for a total of 1 000 000 cycles (+ 50 000/0 cycles),
34、 while maintaining test conditions as shown in Table 4. Starting at 104 C, vary the ambient air temperature from 104 C to -40 C at 250 000 vibration cycle intervals, approximately 7 h intervals. Using a mass flow meter, observe for fitting leakage during and after the test. TABLE 4 - VIBRATION TEST
35、REQUIREMENTS Test Cycles Test Pressure (kPa) Test Temperature (C) 0/250 000 0 104 250 001/500 000 0 40 500 001/750 000 830 104 750 001/1 000 000 830 40 3.3.5 Acceptance Criteria The test is considered a failure if the average leakage per fitting on any assembly at test temperatures exceeds the amoun
36、ts listed in Table 3. SAE J2494-3 Revised AUG2007 - 6 - 3.4 Fitting Separation Pressure Test Requirements (5 specimens) 3.4.1 Description This test is intended to evaluate fitting retention at proof pressure of 2760 kPa 70 kPa and at minimum separation pressure. 3.4.2 Apparatus The test apparatus co
37、nsists of a suitable source of hydraulic pressure and the necessary gauges and piping. 3.4.3 Test Specimens Cut a minimum of 5 tubing specimens to obtain 300 mm between fittings after assembly. Assemble fittings to the tubing using the manufacturers recommendations. 3.4.4 Procedure Plug one end of t
38、he test specimen and mount in the apparatus with the end unrestrained. Apply proof pressure at ambient temperature, to the test specimen and hold for 30 s. Increase pressure at a constant rate so as to reach the specified minimum separation pressure within a time period of 3 to 15 s. 3.4.5 Acceptanc
39、e Criteria Fittings shall not separate from the tubing nor shall the assembly visibly leak at less than specified minimum separation pressure of 5500 kPa 70 kPa. 3.5 Frozen Water Retention Test (5 specimens) 3.5.1 Description This test is intended to evaluate the effects of frozen water on fitting r
40、etention while assembly is pressurized to 2760 kPa 70 kPa. 3.5.2 Apparatus The test apparatus consists of a suitable source of pneumatic pressure and the necessary gauges and piping. 3.5.3 Test Specimens The tubing specimens shall be obtained from current production stock and cut to a length suffici
41、ent to obtain 150 mm 6 mm of tubing between end fittings after assembly. Assemble fittings to the tubing using the manufacturers recommendations. 3.5.4 Procedure Submerge one end of fitting assembly in water for 15 s, then remove the specimens from the water making sure the orientation of the fittin
42、g is such that no water is allowed to drain. Place test specimens in 10 C air for a minimum of 1 h or until completely frozen. Conduct pressure test on the specimens while at 10 C by applying 2760 kPa 70 kPa pneumatic pressure and hold for 5 min. 3.5.5 Acceptance Criteria Fittings shall not separate
43、 from the tubing at the specified minimum test pressure of 2760 kPa. SAE J2494-3 Revised AUG2007 - 7 - 3.6 Reassembly Test (5 specimens) 3.6.1 Description This test is intended to evaluate the effects of repeated assembly and disassembly of a tube and fitting. Leakage rate is used to gauge acceptabi
44、lity. 3.6.2 Apparatus The test apparatus consists of a suitable source of pneumatic pressure and the necessary gauges and piping. A mass flow meter capable of determining air leakage shall be provided. 3.6.3 Test Specimens Cut a minimum of 5 tubing specimens to obtain 300 mm between fittings after a
45、ssembly. Assemble fittings to the tubing using manufacturers recommendations. 3.6.4 Procedure The tube and fitting connections shall be assembled, pressurized to 830 kPa 70 kPa pneumatic for 5 min (+0.5/-0.0 min), depressurized and disassembled five times. Tube end must not be trimmed between each a
46、ssembly and disassembly cycle. Reassemble a sixth time and pressurize the test specimen to 830 kPa 70 kPa with pneumatic pressure at ambient temperature, hold for 5 min and check for leakage. 3.6.5 Acceptance Criteria The test is considered a failure if the average leakage per fitting on any assembl
47、y at test temperatures exceeds the amounts listed in Table 3. 3.7 Oil Compatibility Test (5 specimens) 3.7.1 Description This test is intended to evaluate the effects of contaminated compressor oil as described in SAE J2024 Section 3 at high and low temperatures on fitting performance. 3.7.2 Apparat
48、us The test apparatus consists of a suitable source of hydraulic pressure, 1035 kPa and necessary gauges and piping in environmental test chambers at 100 C and 40 C. 3.7.3 Test Specimens Cut a minimum of 5 tubing specimens to obtain a minimum of 300 mm between fittings after assembly. Assemble fitti
49、ngs to the tubing using manufacturers recommendations. 3.7.4 Procedure Fill test specimens with contaminated oil mixture consisting of 11 parts SAE 15W40CD type oil and 1 part SOFTC-2A contaminates. Subject specimens to 100 C, and atmospheric pressure for 72 h (+1/0.0 h), then apply internal pressure of 1035 kPa 70 kPa for 5 min while maintaining temperature of 10
