1、Designation: D4174 17Standard Practice forCleaning, Flushing, and Purification of Petroleum FluidHydraulic Systems1This standard is issued under the fixed designation D4174; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers aid for the equipment manufacturer,the installer, the oil supplier and the operator in coordi
3、natingtheir 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 isrequired throughout all phases of design, fabricat
4、ion,installation, flushing, testing, and operation of hydraulic sys-tems to minimize and reduce the presence of contaminants andto obtain optimum system reliability.1.2 This practice is presented in the following sequence:SectionScope 1Referenced Documents 2Terminology 3Significance and Use 4Types o
5、f Contamination 5General 5.1Water 5.2Soluble Contaminants 5.3Insoluble Contaminants 5.4Lodged Contamination 5.4.2.1Suspended or Loose Contamination 5.4.2.2Contamination Control 6General 6.1Initial Filling 6.1.1In-Service Units 6.1.2Connection of Contamination Control System 6.1.3Piping or Tubing Con
6、tamination 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 6.3.2.1SectionFilters 6.3.2.2Supplementary Methods 6.3
7、.3Limitations of Contamination Control Devices 6.3.4Storage 7General 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 9.2Fluid Heating Prior to Flush
8、ing 9.3Selection of Flushing Oils 9.4System Operation Fluid 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 Flushing and Flush Acceptance Crit
9、eria 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 10Preinstallation 10.2In-Service Units 10.3Decision to Flush In-Service Hydraulic Systems 10.4Fl
10、uid Condition Monitoring 11Fluid Sampling Techniques 11.2Visual Inspection 11.3Laboratory Analysis 11.4Fluid Cleanliness Criteria 11.5General Information 12Centrifuge Ratings 12.2Coalescence 12.3Vacuum Dehydration 12.4Adsorption 12.51.3 The values stated in SI units are to be regarded as thestandard
11、. The values given in parentheses are for informationonly.1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts, Liquid Fuels, and Lubricants and is the direct responsibility of D02.N0 onHydraulic Fluids.Current edition approved Dec. 1, 2017. Published January 2018. Ori
12、ginallyapproved in 1982. Last previous edition approved in 2015 as D4174 15. DOI:10.1520/D4174-17.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international stand
13、ard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.11.4 Th
14、is standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 T
15、his international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trad
16、e (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D664 Test Method for Acid Number of Petroleum Productsby Potentiometric TitrationD974 Test Method for Acid and Base Number by
17、Color-Indicator TitrationD1774 Test Method for Elastic Properties of Textile Fibers(Withdrawn 2000)3D2709 Test Method for Water and Sediment in MiddleDistillate Fuels by CentrifugeD4006 Test Method for Water in Crude Oil by DistillationD7042 Test Method for Dynamic Viscosity and Density ofLiquids by
18、 Stabinger Viscometer (and the Calculation ofKinematic Viscosity)D7546 Test Method for Determination of Moisture in Newand In-Service Lubricating Oils and Additives by RelativeHumidity SensorD7647 Test Method for Automatic Particle Counting ofLubricating and Hydraulic Fluids Using Dilution Tech-niqu
19、es to Eliminate the Contribution of Water and Inter-fering Soft Particles by Light ExtinctionF311 Practice for Processing Aerospace Liquid Samples forParticulate Contamination Analysis Using Membrane Fil-tersF312 Test Methods for Microscopical Sizing and CountingParticles from Aerospace Fluids on Me
20、mbrane FiltersF313 Test Method for Insoluble Contamination of HydraulicFluids by Gravimetric Analysis (Withdrawn 1988)32.2 ANSI Standards:B93.2 Glossary of Terms for Fluid Power4B93.19 Method for Extracting Fluid Samples from the Linesof an Operating Hydraulic Fluid Power System (forParticulate Cont
21、amination Analysis)43. Terminology3.1 Definitions:3.1.1 nominal filtration ratingan arbitrary micrometrevalue 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 satisfactorype
22、rformance and long life of the equipment. Prerequisites forproper lubrication and component performance are: (1)awell-designed hydraulic system, (2) the use of a suitable fluid,and (3) a maintenance program including proper filtrationmethods to ensure that the fluid is free of contaminants. Thesepre
23、requisites are meaningless unless the hydraulic system isinitially cleaned to a level that will prevent component damageon initial start up or when debris may be dislodged by anysystem upset.4.2 The cleaning and flushing of both new and used systemsare accomplished by essentially the same procedure.
24、 In newsystems, the emphasis is on the removal of contaminantsintroduced during the manufacture, storage, field 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 contaminants
25、introduced during overhaul. Both new and used systems maybenefit from high velocity flushing to remove materials that cancollect in hard to drain pockets or normally non-wettedsurfaces.4.3 While the flushing and cleaning philosophies stated inthis practice are applicable to all primary and servo hyd
26、raulicsystems, 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 flushing and cleaning the hydraulic
27、 systemsshould be accomplished through the cooperative efforts andagreement of the equipment manufacturer, the installer, theflushing service vendor, the operator, and the fluid supplier. Nophase of these procedures should be undertaken without athorough understanding of the possible effects of impr
28、opersystem preparation. The installation and cleaning and flushingof the equipment should not be entrusted to persons lacking inexperience.5. Types of Contamination5.1 GeneralHydraulic systems can become contaminatedfrom a variety of sources. Generally, there are five categories ofcontamination: (1)
29、 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 flush a
30、re 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 50 ppm
31、of water2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standar
32、d is referenced onwww.astm.org.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.D4174 172at 21 C (70 F) and 250 ppm at 71 C (160 F). The water insolution has no adverse effect on lubricating properties of thefluid and causes no corrosion; how
33、ever, when fluid passesthrough a cooler some water may come out of solution andbecome free water in the form of finely dispersed droplets.Many contaminants hinder the separation of this free waterfrom the fluid by settling and may cause an emulsion. Inhydraulic fluids, the emulsion impairs circulati
34、on, interferewith lubrication and adversely affect contamination controlequipment.5.2.1 Water contamination can be classified as either freshor sea water, as encountered in land or marine systems. Freshwater enters the hydraulic system from moist air ascondensation, through improperly located vents,
35、 leaks incoolers, and steam heaters, and because of improper operation.Sea water, in marine hydraulic systems, enters through leaks incoolers, faulty manhole gaskets, faulty sump tank seals andimproperly located vents. Sea and brackish water can alsopresent a problem when used as a coolant in land-b
36、ased units.Water contamination in hydraulic fluids can:5.2.1.1 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 Cause additive depletion and drop-out.5.2.1.8 Adversely affect lub
37、ricating properties.5.2.1.9 Promote bacteria growth.5.2.1.10 Alter fluid viscosity.5.2.1.11 Adversely affect fine filtration (that is, excessiveback pressure).5.2.1.12 Promote cavitation.5.2.2 In the case of severe salt water contamination, it isnecessary to remove the operating fluid and clean and
38、flush thehydraulic systems.5.3 Soluble Contaminants:5.3.1 Soluble contaminants in hydraulic systems includecleaning chemicals, solvents, rust preventives, incompatiblelubricants, flushing oils, extraneous oils, oxidation products,gasket sealants, and assembly lubricants. These contaminantscannot be
39、removed by conventional fluid contamination controlequipment. Normally, a new charge of fluid accompanied witha displacement flush oil is required to correct the problem.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 R
40、esult in sludge deposits.5.3.1.5 Attack elastomeric seals.5.3.1.6 Initiate additive-water interaction that can causeemulsification, possible additive loss, instability, impairedpurification equipment performance, foaming, and air entrain-ment.5.3.1.7 Accelerate oxidation.5.3.2 When a soluble contami
41、nant is present, the fluidsupplier and he equipment manufacturer should be consultedregarding the advisability of continued use of the fluid orreplacing it with a new charge.5.4 Insoluble Contaminants:5.4.1 Insoluble contaminants normally encountered aremetal particles (including rust) of all types
42、and sizes, fibers,airborne solids, sand, and other nonmetallic particles. Thesecontaminants are often the result of improper manufacturingtechniques, improper shipping and storage practices, andcareless installation of hydraulic systems. Some of the effectsof solid contamination are:5.4.1.1 Abrasive
43、 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/filter 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-oi
44、l 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 ContaminationThese contaminants maybecome dislodged by high fluid flows and temperature differ-entials or by induced vibration during flush
45、ing. 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 system upsets. Experience,good judgement, and careful inspection by the installationsupervisor must be relied upon to determine wh
46、en such dirt hasbeen satisfactorily removed.5.4.2.2 Suspended or Loose Contamination:5.4.2.3 Contaminants suspended in the fluid can be gener-ated by particles coming loose from pipe, hose, hydrauliccomponents, tank walls generally caused by high fluid velocity,wear debris, and vibration. Suspended
47、contaminant can bemeasured, as described in 11.3 and 11.4. To prevent the level ofsuspended contaminant from getting beyond acceptable limits,hydraulic system filtration can be augmented with a bypasscontamination control system (fluid filter or centrifuge). Pref-erably a full flow filter or a full
48、flow filter plus bypasspurification is provided. When a full flow filter is used, abypass purification system may not be required.5.4.2.4 The bypass or full flow system, or both, can be inoperation during the flush operation as well as on a continuousbasis during hydraulic system operation. High-vel
49、ocity flusheswill require appropriately sized full flow filters. The rated flowcapacity per hour of a bypass system should be 10 to 20 % ofthe total system fluid volume.6. Contamination Control6.1 GeneralContamination control in a hydraulic systemis the complete 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 from entering the
