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 theref
2、rom, 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 2009 SAE International All rights reserved. No part of this publication ma
3、y 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.orgSURFACEVEHICLERECOMMENDEDPRACTICEJ2470 JAN2009 Issued 1999-10Revised 2009-01 Superseding J2470 NOV2006 Hydraulic Fluid PowerValvesMethod for Assessing the Lock Sensitivity to Contaminants RATIONALEThe primary reasons f
5、or this revision are to identify current sources for the carbonyl iron contaminant and to update the requirements to reflect the currently available carbonyl iron contaminants. The sources of all test contaminants and the listing of laboratories with capability to conduct the test have also been upd
6、ated. FOREWORDNOTE: Some Test Procedures are potentially dangerous. SAE Technical Reports do not purport to address all of the safety problems, if any, associated with their use. It is the responsibility of the user of an SAE Technical Report to establish and employ appropriate safety practices. Onl
7、y individuals who have been properly trained in the test procedure and who are aware of any hazards that may be present should conduct the tests. Appropriate safety and health precautions must be employed when conducting any test. 1. SCOPE 1.1 This SAE Recommended Practice defines a procedure, which
8、 will aid in assessing the contaminant sensitivity of hydraulic valves. The approach taken defines a test procedure with flexibility for testing valves in a wide range of contamination levels. The user of this procedure must establish the contamination levels for testing. Three levels are suggested
9、which should cover the range for most valve applications. This procedure does not establish the contaminant sensitivity requirements for any valve. The user of this procedure needs to be aware of the system contamination level that the valve will operate in and select test contamination levels signi
10、ficantly higher than the operating level to assess the suitability of the valve. The test procedure permits a valve to be tested without disassembly and therefore permits protection of proprietary design information. 1.2 This procedure assesses the contamination sensitivity of valves by contaminant
11、lock. The procedure indicates the sensitivity of valves by contaminant lock due to various sizes of contaminants. The test is designed to assess the contaminant sensitivity of valves in tests of relatively short duration. See Appendix A for guidance as to how the tests and their results may be used.
12、 1.3 The tests are purposely designed to be severe in order to be applicable to a wide range of contaminated environments. The use of valves in many applications and for various purposes results in differing levels of acceptable performance. That is, the same valve may be unacceptable in relation to
13、 operation in a contaminated environment in one application and be acceptable in another. The user must make that decision based on a review of the expected level of the specific application and the test results obtained. NOTE: See 7.2 if document is to be contractually invoked. SAE J2470 Revised JA
14、N2009 Page 2 of 132. REFERENCES 2.1 Applicable Publications The following documents form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of the documents shall be used except in those cases where an invitation for bid or procurement contract
15、specifically identifies the issues in effect on a particular date.2.1.1 SAE Publications Available from SAE International, 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 ARP490 Electrohydraulic Servovalves S
16、AE ARP785 AerospaceProcedure for the Determination of Particulate Contamination in Hydraulic Fluids by the Control Filter Gravimetric Procedure 2.1.2 ISO Publications Publisher: International Organization for Standardization, 1 rue de Varembe, CH-1211 Geneva 20, Switzerland. Available from American
17、National Standards Institute (ANSI) www.ansi.org or from the National Fluid Power Association (NFPA) .ISO 1219-1 Graphic symbols for conventional use and data-processing applications ISO 4021 Hydraulic fluid powerParticulate contamination analysisExtraction of fluid samples from lines of an operatin
18、g system ISO 4405 Hydraulic fluid powerFluid contaminationDetermination of particulate contamination by the gravimetric method ISO 4406 Hydraulic fluid powerMethod for coding the level of contamination by solid particles ISO 5598 Fluid power systems and componentsVocabulary ISO 6403 Hydraulic fluid
19、powerValves controlling flow and pressureTest methods ISO 10770-1 Hydraulic fluid powerElectrically modulated hydraulic control valvesPart 1: Test methods for four-way directional flow control valves ISO 10770-2 Hydraulic fluid powerElectrically modulated hydraulic control valvesPart 2: Test methods
20、 for three-way directional flow control valves ISO 11500 Hydraulic fluid powerDetermination of the particulate contamination level of a liquid sample by automatic particle counting using the light-extinction principle ISO 12103-1 Road vehiclesTest dust for filter evaluationPart 1: Arizona test dust
21、ISO 16889 Hydraulic fluid powerFiltersMulti-pass method for evaluating filtration performance of a filter element SAE J2470 Revised JAN2009 Page 3 of 133. DEFINITIONS For definitions of other terms, see ISO 5598. 3.1 Contaminant Lock/Silt Lock The process of restricting movement by contaminant build
22、up between two surfaces which move in relation to each other, such as spool/bore or spool/sleeve assemblies. 3.2 Contaminant Sensitivity The change in valve performance caused by particulate contaminants in the fluid. 4. TEST REQUIREMENTS 4.1 Test Equipment 4.1.1 The test system shall consist of a h
23、ydraulic test circuit, as illustrated in Figure 1, comprising of a reservoir, a pumping unit, an injection system, a heat exchanger, a flow-meter, pressure gauges, a temperature indicator, a relief valve, a control valve, and cleanup control filters. Select components for the test circuit that are o
24、f a design known to function satisfactorily with contaminated fluid. 4.1.2 Construct the reservoir with a conical bottom having an included angle of less than 90 degrees to ensure sufficient fluid agitation. Diffuse the hydraulic fluid entering the reservoir below the surface of the fluid. 4.1.3 Con
25、struct an injection chamber, which will ensure that no contaminant is trapped in the injection chamber. A chamber with a volume of approximately 500 mL, with a length to diameter ratio of approximately 10 and having a conical bottom with an included angle of less than 90 degrees, is recommended.4.1.
26、4 Use a heat exchanger that does not constitute a contaminant trap. NOTE: It is recommended that either a one or two-pass unit be used and mounted vertically with the hydraulic fluid entering the heat exchanger from the bottom. It is also recommended that the hydraulic fluid be circulated through th
27、e tube side and the water through the shell side. 4.1.5 Use a flowmeter that is insensitive to contaminant and is accurate to within 2% of full value. 4.1.6 Use control filters which are capable of providing a contaminant background of less than or equal to 40 particles/mL greater than 5 m size and
28、less than or equal to 10 particles/mL greater than 15 m size. 4.1.7 Provide a facility for gravimetric measurement of the contamination level of the fluid in accordance with SAE ARP785 or ISO 4405. 4.1.8 The test circuit requires one or more bypass throttling valves to maintain flow and pressure. Wh
29、en the test valve is in a position that permits flow through the test valve, the throttling bypass valve V-1 shall be closed and V-2 adjusted to maintain the required pressure. The test circuit may require slight modifications to suit the particular valve being tested. For valves with one or more ex
30、ternal pilots, a pilot line will be required. Unless otherwise specified, pilot lines shall be subjected to the same contaminant source as the rest of the test valve. A relief valve or rupture disc may be incorporated into the system to protect the pump, however, no fluid should pass through it duri
31、ng the testing of the valve at selected positions. (Flow through the relief at time of shifting is permissible for blocked center valves and valves with blocked crossover.) SAE J2470 Revised JAN2009 Page 4 of 13FIGURE 1 - TYPICAL VALVE CONTAMINANT SENSITIVITY TEST CIRCUIT 4.2 Test Fluid and Volume 4
32、.2.1 Use a mineral oil ISO viscosity grade 32 fluid, unless the customer identifies a specific fluid. Report the fluid specification, brand name, supplier, and batch identification. 4.2.2 A test system (exclusive of the system cleanup filter circuit) with a fluid volume that is numerically equal to
33、one-fourth to one-half the designated test volume flow per minute is recommended. In some valve positions, there will only be leakage flow through the valve. However, flow must be kept relatively high to keep the contaminant in suspension in order to qualify the system. In other valve positions, the
34、 force to shift the valve may be a function of the flow rate and operating pressures and the maximum shift forces may occur at specific flow and pressure conditions. The fluid volume shall be recorded. SAE J2470 Revised JAN2009 Page 5 of 134.3 Materials 4.3.1 Have available a supply of clean fluid s
35、ample bottles with a required cleanliness level of less than 10 particles greater than 10 m per mL of bottle volume in accordance with ISO 4021.4.3.2 Have available a supply of clean slurry injection bottles. 4.4 Precautions 4.4.1 Ensure that the connecting lines and the hydraulic components are of
36、such size that turbulent mixing will exist throughout the test circuit, including the test valve.4.4.2 Take precautions to prevent contaminant traps, silting areas, and combinations of cyclonic separation zones and quiescent chambers. Also ensure that the test system does not exhibit the presence of
37、 entrained air. 4.5 Selection of Test Contaminants and Concentrations 4.5.1 Test Contaminant Table 1 lists two options for the silt lock contaminant. For Option A, the contaminant to be used is the size of ISO 12103-1 A1 Ultrafine or A3 Medium Arizona test dust or a classified cut of one of these te
38、st dusts. The contaminant for Option B is a mixture of the test dust and carbonyl iron. Table 2 lists the carbonyl iron grades. a. Option AIn Option A, classified Arizona test dust is the only contaminant. Option A is recommended for testing when the magnetic properties of the contaminant are not a
39、concern. This is generally the case except for electrically operated valves. b. Option BIn Option B, the contaminant, in each size range through 40 m, is a mixture of Arizona test dust and Carbonyl Iron (C.I.). In the 0 to 80 m size range, the contaminant is the same as Option A. Option B is recomme
40、nded for electrically operated valves. For Option B, the mixture by weight is 50% Arizona test dust and 50% C.I. The C.I. particles have a density of approximately three times that of the test dust particles. Therefore, for Option B, the majority of the particles will be Arizona test dust, as in Opt
41、ion A, with the total number of particles in Option B about two-thirds the number in Option A. TABLE 1 - TEST CONTAMINANTS RunContaminantsTest Dust ISO 12103-1 (size)ContaminantsCarbonylIron(grade)OptionsAOptionsB1 0 5 m (See 4.5.4) SF 100%Test Dust of Specified Size 50% Test Dust of specified size
42、and50% C. I. of the specified size (by weight) 2 0 10 m ISO 12103-1 A-1 ultrafine dust SM3 0 20 m (See 4.5.4) SC4 0 40 m (See 4.5.4) None Same as Option A 5 0 80 m ISO 12103-1 A3 medium dust None Same as Option A SAE J2470 Revised JAN2009 Page 6 of 13TABLE 2 - CARBONYL IRON GRADES Grade Designator A
43、verage Size -MicrometresTypical Size Range - Micrometres SourceSF 1 - 3 1 - 9 See Appendix B SM 3 - 5 1 -12 SC 7 - 9 4.5.2 Contaminant Concentration Levels Table 3 identifies three concentrations of contaminants recommended for testing. These levels are 10, 50, and 100 mg of contaminant per liter of
44、 fluid. These three levels should be adequate to cover all hydraulic systems applications. As indicated in Table 3, the ingression rate and system filtration characteristics can be considered in the selection process. However, since silt-lock can result in valve and system failure, it is prudent to
45、select a contaminant level of not less than the maximum contaminant level which may occur rather than the normal operating level. In general, a level at least 7 to 10 times that of the normal operating level is recommended. In comparing different valves and in determining required filtration levels,
46、 it will generally be more efficient to first conduct tests at the highest concentration level of interest. TABLE 3 - RECOMMENDED VALVE TEST CONTAMINANT CONCENTRATIONS ConcentrationX(mg/L)Tolerance (mg/L) Valve Application 10 1 Limited contaminant ingression, system possesses high degree of filtrati
47、on 50 5 Some contaminant ingression, system possesses some degree of filtration 100 10 Heavy contaminant ingression, system possesses little or no degree of filtration 4.5.3 Selection of Test Contaminant Size Ranges A complete test would consist of 5 runs each with a different size range of contamin
48、ant as identified in Table 1. However, in many cases testing with a reduced number of contaminant ranges will be satisfactory and will reduce test time and costs. For non-electrical valves, the test contaminants for runs 2 (0 to 10 m) and 5 (0 to 80 m) are recommended for reduced testing. If a valve
49、 should perform unsatisfactorily in one of these size ranges, additional testing can be conducted to more accurately determine the size contaminant to which the valve is sensitive. Similarly, for electrically operated valves, contaminants for run 2 (0 to 10 m), run 3 (0 to 20 m) and run 4 (0 to 40 m) are recommended for reduced testing. For electrically operated valves in systems
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