1、Designation: D 4174 89 (Reapproved 2005)An American National StandardStandard Practice forCleaning, Flushing, and Purification of Petroleum FluidHydraulic Systems1This standard is issued under the fixed designation D 4174; the number immediately following the designation indicates the year oforigina
2、l adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers aid for the equipment manufacturer,the insta
3、ller, the oil supplier and the operator in coordinatingtheir efforts towards obtaining and maintaining clean petro-leum fluid hydraulic systems. Of necessity, this practice isgeneralized due to variations in the type of equipment, build-ers practices, and operating conditions. Constant vigilance isr
4、equired throughout all phases of design, fabrication, installa-tion, flushing, testing, and operation of hydraulic systems tominimize and reduce the presence of contaminants and toobtain optimum system reliability.1.2 This practice is presented in the following sequence:SectionScope 1Referenced Docu
5、ments 2Significance and Use 3Definitions 4Types of Contamination 5General 5.1Water 5.2Soluble Contaminants 5.3Insoluble Contaminants 5.4Lodged Contamination 5.4.2.1Suspended Contamination 5.4.2.2Contamination Control 6General 6.1Initial Filling 6.1.1In-Service Units 6.1.2Connection of Contamination
6、Control System 6.1.3Piping to Contamination Control System 6.1.4Contamination Control Procedures 6.2Full Flow Contamination Control 6.2.1Bypass Contamination Control 6.2.2Batch Contamination Control 6.2.3Contamination Control Processes 6.3Gravity 6.3.1Mechanical 6.3.2Centrifuge 6.3.2.1Filters 6.3.2.
7、2Supplementary Methods 6.3.3Limitations of Contamination Control Devices 6.3.4Storage 7SectionGeneral 7.1Inspection 8General 8.1System Components 8.2Valves, Strainers and Coolers 8.2.1Sumps and Tanks 8.2.2Control Devices 8.2.3Pumps 8.2.4Flushing Program 9General 9.1Preparation of System for Flushing
8、 9.2Oil Heating Prior to Flushing 9.3Selection of Flushing Oil 9.4System Operation Oil 9.4.1Special Flushing Oil 9.4.2Flushing Oil Selection Guide 9.4.3Flushing Procedure for New Systems 9.5Flushing Oil Charge 9.5.1Cleaning of Filtration Devices 9.5.2Cleaning of System Components 9.5.3System Flushin
9、g 9.5.4Draining of Flushing Oil 9.5.5Displacement Oil 9.5.6Interim Corrosion Protection 9.5.7New Fluid Charge 9.5.8Flushing of Used Systems 9.6General Guidelines 9.6.1Procedure 9.6.2System Maintenance 10Shipping 10.1Preinstallation 10.2In-Service Units 10.3Decision to Flush In-Service Hydraulic Syst
10、ems 10.4Fluid Condition Monitoring 11Fluid Sampling Techniques 11.2Visual Inspection 11.3Laboratory Analysis 11.4Fluid Cleanliness Criteria 11.5General Information 12Filter Ratings 12.2Centrifuge Ratings 12.3Coalescence 12.4Vacuum Dehydration 12.5Adsorption 12.61.3 The values stated in SI units are
11、to be regarded as thestandard. The values given in parentheses are for informationonly.1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts and Lubricants and is the direct responsibility of D02.N0 on HydraulicFluids.Current edition approved May 1, 2005. Published May
12、2005. Originallyapproved in 1982. Last previous edition approved in 1999 as D 4174 89 (1999).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.1.4 This standard does not purport to address all of thesafety concerns, if any, associated
13、with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 445 Test Method for Kinematic Viscosity of Transparentand Opaq
14、ue Liquids (the Calculation of Dynamic Viscos-ity)D 664 Test Method forAcid Number of Petroleum Productsby Potentiometric TitrationD 974 Test Method for Acid and Base Number by Color-Indicator TitrationD 1774 Test Method for Elastic Properties of Textile Fibers3D 2709 Test Method for Water and Sedim
15、ent in DistillateFuels by CentrifugeD 4006 Test Method for Water in Crude Oil by DistillationF311 Practice for ProcessingAerospace Liquid Samples forParticulate Contamination Analysis Using Membrane Fil-tersF 312 Methods for Microscopical Sizing and CountingParticles from Aerospace Fluids on Membran
16、e FiltersF 313 Test Method for Insoluble Contamination of Hydrau-lic Fluids by Gravimetric Analysis32.2 ANSI Standards:B93.2 Glossary of Terms for Fluid Power4B93.19 Method for Extracting Fluid Samples from theLines of an Operating Hydraulic Fluid Power System (forParticulate Contamination Analysis)
17、43. Terminology3.1 Definitions:3.1.1 absolute filtration ratingthe diameter of the largesthard spherical particle that will pass through a filter underspecified test conditions. This is an indication of the largestopening in the filter element.3.1.2 nominal filtration ratingan arbitrary micrometreva
18、lue indicated by a filter manufacturer. Due to lack ofreproducibility this rating is deprecated. (ANSI B93.2)4. Significance and Use4.1 Proper fluid condition is essential for the satisfactoryperformance and long life of the equipment. Prerequisites forproper lubrication and component performance ar
19、e: (1)awell-designed hydraulic system, (2) the use of a good fluid, and(3) a maintenance program including proper filtration methodsto ensure that the fluid is free of contaminants. These prereq-uisites are meaningless unless the hydraulic system is initiallycleaned to a level that will prevent comp
20、onent damage oninitial start up or when debris may be dislodged by any systemupset.4.2 The cleaning and flushing of both new and used systemsare accomplished by essentially the same procedure. In newsystems, the emphasis is on the removal of contaminantsintroduced during the manufacture, storage, fi
21、eld fabrication,and installation. In used systems, the emphasis is on theremoval of contaminants that are generated during operations,from failures that occur during operation; or contaminantsintroduced during overhaul.4.3 While the flushing and cleaning philosophies stated inthis practice are appli
22、cable to all primary and servo hydraulicsystems, the equipment specified herein does not apply tocompact systems that use relatively small volumes of fluidunless they are servo systems where it is economically justi-fied.4.4 It should be emphasized that the established proceduresto be followed for f
23、lushing and cleaning the hydraulic systemsshould be accomplished through the cooperative efforts andagreement of the equipment manufacturer, the installer, theoperator, and the fluid supplier. No phase of these proceduresshould be undertaken without a thorough understanding of thepossible effects of
24、 improper system preparation. The installa-tion and cleaning and flushing of the equipment should not beentrusted to persons lacking in experience.5. Types of Contamination5.1 GeneralHydraulic systems can become contaminatedfrom a variety of sources. Generally, there are five categories ofcontaminat
25、ion: (1) water, (2) fluid soluble material, (3) fluidinsoluble material, (4) erroneous fluid additions, and (5)hydraulic fluid deterioration. Properly designed systems cannormally control water and insoluble contaminants; however,when it is necessary to remove soluble contaminants, a fluidchange and
26、 flush are required.5.2 WaterWater is almost always present in hydraulicfluids. It may be present in solution or in a free or emulsifiedform. Water can exist in solution at varying concentrationsdepending on the nature of the fluid, the temperature, and soforth. For example, hydraulic fluid may hold
27、 50 ppm of waterat 21C (70F) and 250 ppm at 71C (160F). The water insolution has no adverse effect on lubricating properties of thefluid and causes no corrosion; however, when fluid passesthrough a cooler some water may come out of solution andbecome free water in the form of finely dispersed drople
28、ts.Many contaminants hinder the separation of this free waterfrom the fluid by settling and may cause an emulsion. Inhydraulic fluids, the emulsion impairs circulation, interferewith lubrication and adversely affect contamination controlequipment.5.2.1 Water contamination can be classified as either
29、 freshor sea water, as encountered in land or marine systems. Freshwater enters the hydraulic system from moist air as condensa-tion, through improperly located vents, leaks in coolers, andsteam heaters, and because of improper operation. Sea water, inmarine hydraulic systems, enters through leaks i
30、n coolers,faulty manhole gaskets, faulty sump tank seals and improperlylocated vents. Sea and brackish water can also present a2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information
31、, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.D 4174 89 (2005)2problem when used as a coolant in land-based units. Watercontamination in hydraulic fluids can:5.2.
32、1.1 Promote fluid oxidation.5.2.1.2 Reduce fluid stability.5.2.1.3 Promote sludge.5.2.1.4 Promote foaming.5.2.1.5 Form emulsions.5.2.1.6 Promote rusting and corrosion.5.2.1.7 Affect additive and concentration.5.2.1.8 Adversely affect lubricating properties.5.2.1.9 Promote bacteria growth.5.2.1.10 Al
33、ter fluid viscosity.5.2.1.11 Adversely affect fine filtration.5.2.2 In the case of severe salt water contamination, it isnecessary to remove the operating fluid and clean and flush thehydraulic systems.5.3 Soluble Contaminants:5.3.1 Soluble contaminants in hydraulic systems includecleaning chemicals
34、, solvents, rust preventives, incompatiblelubricants, flushing oils, extraneous oils, oxidation products,gasket sealants, and assembly lubricants. These contaminantscannot be removed by conventional fluid contamination controlequipment. Normally, a new charge of fluid is required tocorrect the probl
35、em. Fluid soluble contaminants can:5.3.1.1 Change the fluid viscosity.5.3.1.2 Alter the flash point.5.3.1.3 Change the color.5.3.1.4 Result in sludge deposits.5.3.1.5 Attack elastomeric seals.5.3.1.6 Initiate additive-water interaction that can causeemulsification, possible additive loss, instabilit
36、y, impairedpurification equipment performance, foaming, and air entrain-ment.5.3.1.7 Accelerate oxidation.5.3.2 When a soluble contaminant is present, the fluidsupplier and consult the equipment manufacturer should beconsulted regarding the advisability of continued use of thefluid or replacing it w
37、ith a new charge.5.4 Insoluble Contaminants:5.4.1 Insoluble contaminants normally encountered aremetal particles of all types and sizes, fibers, airborne solids,sand, and other nonmetallic particles. These contaminants areoften the result of improper manufacturing techniques, im-proper shipping and
38、storage practices, and careless installationof hydraulic systems. Some of the effects of solid contamina-tion are:5.4.1.1 Abrasive wear or sticking of components such as:control valve poppets, cylinders, piston rods, and seals.5.4.1.2 Faulty control functioning, particularly pluggedfluid lines/filte
39、r plugging.5.4.1.3 Reduced fluid stability.5.4.1.4 Sludge formation.5.4.1.5 Increased foaming tendency.5.4.1.6 Stabilized water-oil emulsions/accelerated oxidationby catalytic effect of metal particles.5.4.2 Harmful contamination can exist in the hydraulicsystem in two forms:5.4.2.1 Lodged Contamina
40、tionThese contaminants maybecome dislodged by high fluid flows and temperature differ-entials or by induced vibration during flushing. Contaminationcan be lodged in unflushed pockets or settled on the bottom oftanks. Unless this contaminant is removed, it becomes dis-lodged during startup or during
41、system upsets. Experience,good judgement, and careful inspection by the installationsupervisor must be relied upon to determine when such dirt hasbeen satisfactorily removed.5.4.2.2 Suspended Contamination:5.4.2.3 (a) Contaminants suspended in the fluid can begenerated by particles coming loose from
42、 pipe, hose, hydrauliccomponents, tank walls generally caused by high fluid velocity,wear debris, and vibration. Suspended contaminant can bemeasured, as described in 11.3. To prevent the level ofsuspended contaminant from getting beyond acceptable limits,all units should be provided at least with a
43、 bypass contamina-tion control system (fluid filter or centrifuge). Preferably a fullflow filter or a full flow filter plus bypass purification isprovided. When a full flow filter is used, a bypass purificationsystem may not be required.5.4.2.4 (b) The bypass or full flow system, or both, are inoper
44、ation during the flush operation as well as on a continuousbasis during hydraulic system operation. The rated flow capac-ity per hour of a bypass system should be 10 to 20 % of thetotal system fluid volume.6. Contamination Control6.1 GeneralContamination control in a hydraulic systemis the complete
45、program of monitoring and maintaining a cleanfluid. Contamination control must begin with the design,manufacture, and installation of the hydraulic system andcontinue throughout the life of the system. When makinginspections or working in or around a unit, care must be takento prevent contaminants f
46、rom entering the system. When workthat generates contaminants is being performed in the vicinityof the hydraulic system, the system components must beprotected even to the extent of suspending operations, andrequiring system components to be sealed until the contami-nating activity has ceased. The c
47、ontamination control systemmust be capable of removing water and particulate matterconsistent with contamination tolerance and system cleanlinessrequirements.6.1.1 Initial FillingWhen initially filling the hydraulicsystem, all fluids are filtered through 3 to 10-m absolute (see4.1) filters as they a
48、re being transferred into the reservoir. Thecontamination control system is ready for operation prior to thehydraulic system fill and is operating throughout flushing. SeeSection 9.5.6.1.2 In-Service UnitsThe contamination control systemis in operation as long as the hydraulic system is in service.
49、Itsoperation is frequently and regularly monitored to assure that itis performing adequately and to determine the need for itsmaintenance.6.1.3 Connection of Contamination Control SystemTheexternal fluid take-off from the circulating system to thecontamination control system is from the lowest point of thefluid sump or reservoir, to facilitate removal of solid contami-nants and water.D 4174 89 (2005)36.1.3.1 Piping between the reservoir and the contaminationcontrol system is designed to minimize the potential for theloss of fluid that results from piping or equipment
