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 revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2013 SAE International All rights reserved. No part of this p
3、ublication may 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: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J1227_201302 SURFACE VEHICLE RECOMMENDED PRACTICE J1227 FEB2013 Issued 1979-06 Re
5、vised 2013-02 Superseding J1227 MAR1986 Assessing Cleanliness of Hydraulic Fluid Power Components and Systems RATIONALE This document was updated to reflect the changes to ISO 4406 contamination rating system, and to update the reference standards section. FOREWORD There is an increasing awareness t
6、hat the reliability, productivity, and economy of use of hydraulic systems is directly related to the cleanliness level achieved. In addition, there is strong evidence that start up failures of both new and overhauled systems are often contaminant-caused catastrophic failures. Contaminant built in t
7、o each component making up a hydraulic system, and contaminant generated in assembling the components and systems, are significant contributors to these failures. Working Group 6 of Subcommittee IV of the SAE Off-Road Machinery Technical Committee agreed to establish a project and to do a survey whi
8、ch showed a significant interest in this subject. This resulted in a Task Group being formed to draft this recommended practice. This SAE Recommended Practice is intended as a guide toward standard practice but may be subject to frequent change to keep pace with experience and technical advances, an
9、d this should be kept in mind when considering its use. 1. SCOPE To describe laboratory methods for determining and reporting the contaminant level of the wetted portion of hydraulic fluid power components, parts, subsystems and systems, and of fill fluids. For each type of item it provides a method
10、 of obtaining the liquid sample and the contamination level thereof. It also includes procedures for establishing a sampling plan and guidelines for establishing levels of acceptance, but does not set those levels. 1.1 Purpose To provide a basis for measuring and reporting cleanliness levels so that
11、 built-in contamination and premature failures of hydraulic systems can be minimized. SAE J1227 Revised FEB2013 Page 2 of 16 2. REFERENCES 2.1 Applicable Documents The following publications form a part of the specification to the extent specified herein. Unless otherwise indicated the latest revisi
12、on of SAE publications shall apply. 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 J1277 Method for Assessing the Cleanliness Level of New Hydraulic
13、Fluid 2.1.2 ISO Publications ISO 4406 Method for coding the level of contamination by solid particles ISO 11171 Calibration of Automatic-Count Instruments for Particles Suspended in Liquids ISO 11500 Determination of Particulate Contamination in Liquids by Automatic Particle Counting (APC) ISO 3938
14、Contamination Analysis - Method for Reporting Analysis Data First Edition ISO 3722 Fluid sample containers - Qualifying and controlling cleaning methods ISO 5598 Fluid power systems and components - Vocabulary ISO 4021 Particulate Contamination Analysis - Extraction of Fluid Samples from Lines of an
15、 Operating System 2.1.3 ANSI/ASQ Publications American Society for Quality 600 North Plankinton Ave., Milwaukee, WI 53203 ASQ Z1.41971 Sampling Procedures and Tables for Inspection by Attributes 2.1.4 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Con
16、shohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org ASTM D6304 Standard Test Method for Determination of Water in Liquid Petroleum Products by Karl Fischer Reagent SAE J1227 Revised FEB2013 Page 3 of 16 3. OUTLINE OF METHOD a. Select the item to be evaluated using a sampling plan per Section 4
17、. b. Obtain representative liquid sample per Section 5. c. The fluid sample should be evaluated per Section 6. d. Report resulting data in accordance with Section 7. e. Compare the results with the requirements of Sections 8, 9, and 10. f. Resolve any disputes using the guidelines of Section 9. g. B
18、efore tests are started verify that all needed information is available in accordance with Section 11. h. Define new terms (see italics) per Section 12. i. Index per Section 13. 4. GUIDELINES FOR ESTABLISHING SAMPLING PLANS In some type systems, adequate reliability requires 100% cleanliness testing
19、 of systems and components. However, for most industrial and mobile hydraulic systems, a sampling plan is justified. Such a sampling plan can vary from the simplicity of testing the first and last item from each lot, to a full statistical sampling plan. Ref. c-1 of Table 1 is a useful guide for esta
20、blishing such a statistical plan. 5. METHODS OF OBTAINING REPRESENTATIVE LIQUID SAMPLES 5.1 Collection methods for obtaining representative liquid samples are considered for the following categories: a. Complete systems and integral subsystems - see 5.2 and 5.3 b. Static components - see 5.2 and 5.4
21、. c. Dynamic components - see 5.2 and 5.5. d. Parts - see 5.2 and 5.6. e. Fill-hydraulic fluid - see 5.7. 5.1.1 Following collection in a verified clean container (see 12.6) the liquid sample is to be evaluated in accordance with the appropriate methods of Section 6. 5.1.2 Items a, b, and c in 5.1 p
22、rovide for collecting a sample from complete components or systems without disassembly. Some may prefer to disassemble the components and to obtain the contaminated sample from the parts. It is unlikely that the contamination removed from the parts will equal that removed from the assembled componen
23、t or system for the following reasons: a. The process of disassembly and assembly generates contaminants. b. Areas of parts may be exposed which are not accessible in the assembled components. c. Moving a dynamic component will generate contaminant which would not be observed when evaluating the par
24、ts. SAE J1227 Revised FEB2013 Page 4 of 16 5.2 General Cautions Applicable to Obtaining Representative Liquid Samples 5.2.1 Reynolds Number It is possible for a unit to test clean when using oil at room temperature, but test dirty when tested with the same oil at high temperature. Likewise, it is po
25、ssible for a unit to test clean during an evaluation and test dirty if evaluated using a higher flow rate or using an oil with lower viscosity. These results are to be expected because the removal of particles from surfaces is proportional to the turbulence in the system which, in turn, is dependent
26、 upon the Reynolds number attained. Ideally, flushing and cleanliness testing should be performed at a Reynolds number which is at least as high as the maximum Reynolds number that the unit will see in normal service. To achieve this, it is sometimes necessary to flush with a low viscosity liquid. R
27、eynolds number can be calculated with the following equations: (Eq. 1) where: R = Reynolds number dimensionless dimensionless V = Fluid velocity feet per second meters per second d = Pipe inside diameter inches millimeters g88 = Viscosity Saybolt seconds centistokes Q = Flow rate U.S. gallons per mi
28、nute liters per minute 5.2.2 Vibration and Shock With some components and systems, a cleanliness level measured at one laboratory will be significantly changed when measured at another laboratory, if the unit is subjected to vibration and shock during transit. Likewise, the cleanliness level of a un
29、it can be significantly changed when installed on a vehicle in field operations. To determine if vibration and shock are significant in altering contaminant levels in a particular case, it is recommended that the unit or system be tested for contamination both before and after being subjected to the
30、 worst vibration and shock expected in shipping and use. 5.2.3 Selecting a Clean Test Liquid (see 12.2) Select a clean test liquid that is compatible with the component or system being evaluated. If different from the system hydraulic fluid assure that either: a. The clean test liquid is totally rem
31、oved so that it does not contaminate the system fluid, OR b. The two liquids are compatibleincluding additive packagesso that the mixture will still meet system requirements. CAUTION: Halogenated hydrocarbons (such as trichloroethane and other chlorinated solvents) have been reported to be a source
32、of accelerated corrosive/erosive wear in hydraulic systems, special precautions should therefore be taken to remove them so as to assure that none can be carried over into the hydraulic fluid. 5.2.4 Draining Components When draining components, care must be exercised to assure that the fluid sample
33、is not contaminated by contact with normally non-wetted surfaces, such as external surfaces and threaded portion of ports. This can be minimized by installing a precleaned fitting into the port (hand tighten without thread sealant) so that the fluid can be poured in a controlled stream into the veri
34、fied clean container. SAE J1227 Revised FEB2013 Page 5 of 16 5.2.5 Location of Sampling Valves Locate sampling taps and valves in a turbulent portion of the line, and above the centerline of any horizontal line so as to avoid trapping contaminants. For maximum assurance that the samples taken and th
35、e counts reported are indeed representative, please also refer to Table 1 Refs. b-1, 2, 3, 4 and 5. 5.2.6 Diffusers Where diffusers are called out (Figure 1, Figure 2, and Figure 3), select type and or size to avoid breaking of fluid surface by returning fluid. 5.2.7 Dilution Factors When Using Circ
36、ulating Systems If the volume of the liquid in the circulating system is large as compared to the volume of the component or subsystem being tested there will be a distortion in the number of large particles reported. This volume ratio should be kept as small as is practical. 5.3 Complete Systems an
37、d Integral Subsystems (Those which can be pressurized and have normal flow such as some hydrostatic and steering systems): 5.3.1 Evaluate complete systems in accordance with Ref. b-7 of Table 1. 5.3.2 Evaluate integral subsystems by withdrawing a sample from the turbulent portion of the pressurized
38、subsystem using the method shown in Table 1 Ref. b-1, or sample from the reservoirif needed. Such sampling should occur after the subsystem has reached an agreed upon temperature, and has been fully exercised and pressurized. The temperature selected should consider both safety and 5.2.1. Exercise s
39、ubsystem by operating a portion of the time at maximum rated flow so as to obtain maximum Reynolds number per 5.2.1, and for a time sufficient to pass ten times the total test system hydraulic fluid volume through the subsystem. While still operating, withdraw the fluid samples into a verified clean
40、 container. If it is necessary to connect the subsystem to a precleaned (g10010% rule) flow test stand the comments of 6.4 and definition of 12.4 should be considered. 5.4 Static components (such as reservoirs, fittings, tubing, filter housings, manifolds, etc.) Static components can be evaluated by
41、 two basic methods. The first (which is historically probably the most commonly used) is a slosh test, which uses movement of a partially filled component to transfer the contaminant from the wetted surfaces of the static component to the clean test liquid. The second method is a flow test and recog
42、nizes the importance of achieving a Reynolds number equal to or greater than that achieved in service (see 5.2.1), and which measures the contaminant increase contributed by the static component to a circulating system. The slosh test is normally simpler and more economical and should suffice, excep
43、t where it can be shown that the flow test removed significantly more contaminant. 5.4.1 Slosh Test Fill the component 1/3 to 1/2 full with clean test liquid and seal the component so that it can be mechanically agitated, vibrated, and shocked so as to loosen contaminants without spilling the test l
44、iquid. A specified plan for agitation, vibration, and shock consistent with the geometry of the component should be followed (see 5.2.2). The sealing method should be validated to assure that it does not add significant contamination. The fluid sample should be removed from large components, using t
45、he method of Table 1 Ref. b-1. Smaller components should be completely drained into a verified clean container (see 5.2.4). SAE J1227 Revised FEB2013 Page 6 of 16 5.4.2 Flow Test Where appropriate, connect the static component to a precleaned (g10010% rule) flow test stand capable of achieving a Rey
46、nolds number at the wetted surfaces of the component at least equal to the maximum it will see in service (see 5.2.1). The test stand can be similar to that shown in Figure 3 with the static component connected at points A and B and the directional control valve (7) positioned such that flow through
47、 the static component is in the normal direction of flow. Flow through the component for a time sufficient to assure that a hydraulic fluid volume at least equal to ten times the test system liquid volume has passed through the component. After the minimum flow time withdraw a sample per Table 1 Ref
48、. b-1 (see 6.4). 5.5 Dynamic Components Dynamic components are considered in the following subcategories: a. Rotating components - pumps and motors - see 5.5.1. b. Reciprocating components - cylinders and accumulators - see 5.5.2. c. Hoses - see 5.5.3. d. Valves - see 5.5.4. Obtain the liquid sample
49、 for each subcategory of dynamic components, as follows: 5.5.1 Rotating Components Connect the components inlet directly to its outlet through a precleaned (g10010% rule) system (see Figure 1) so as to allow the component to be rotated at its maximum speed. Rotate the component at its maximum speed under no load for a length of time sufficient to achieve tenfold minimum circulation of the system oil volume. During rotation, keep the hydrau
