1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58cleaning lines by flushingICS 23.100.40Hydraulic fluid power systems Assembled systems Methods of B
2、RITISH STANDARDBS ISO 23309:2007BS ISO 23309:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 June 2007 BSI 2007ISBN 978 0 580 53009 8Amendments issued since publicationAmd. No. Date CommentsThis publication does not purport to include
3、all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard was published by BSI. It is the UK implementation of ISO 23309:2007.The UK participati
4、on in its preparation was entrusted by Technical Committee MCE/18, Fluid power systems and components, to Panel MCE/18/-/6, Contamination control.A list of organizations represented on this committee can be obtained on request to its secretary.INTERNATIONALSTANDARDISO23309First edition2007-05-15Refe
5、rence numberISO 23309:2007(E)Hydraulic fluid power systems Assembled systems Methods of cleaning lines by flushingTransmissions hydrauliques Systmes assembls Mthodes de nettoyage des canalisations par curageBS ISO 23309:2007iiiiiForewordISO (the International Organization for Standardization) is a w
6、orldwide federation of national standards bodies(ISO member bodies). The work of preparing International Standards is normally carried out through ISOtechnical committees. Each member body interested in a subject for which a technical committee has beenestablished has the right to be represented on
7、that committee. International organizations, governmental andnon-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the InternationalElectrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in a
8、ccordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standardsadopted by the technical committees are circulated to the member bodies for voting. Publication as anInternational Standard requi
9、res approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patentrights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 23309 was prepared by Technical C
10、ommittee ISO/TC 131, Fluid power systems, Subcommittee SC 6,Contamination control.BS ISO 23309:2007ivIntroductionIn hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within anenclosed circuit.The initial cleanliness level of a hydraulic system can aff
11、ect its performance and useful life. Unless removed,particulate contamination present after manufacture and assembly of a system can circulate through the systemand cause damage to the system components. To reduce the probability of such damage, the fluid and theinternal surfaces of the hydraulic fl
12、uid power system need to be flushed clean to a specified level.Flushing of lines in a hydraulic system needs to be viewed as one means of removing in-built and residualcontamination, and ought not be the sole method used for cleaning such systems.BS ISO 23309:20071Hydraulic fluid power systems Assem
13、bled systems Methods of cleaning lines by flushing1ScopeThis International Standard specifies the procedures for flushing from the hydraulic lines of larger hydraulic fluidpower systems solid particulate contamination that can be introduced during the initial build of a new hydraulicsystem or after
14、maintenance or modification of an existing system.This International Standard supplements, but does not replace, the requirements of the component supplier andcustomer, especially when those requirements are stricter than those specified by this International Standard.This International Standard is
15、not applicable toa) the chemical cleaning and pickling of hydraulic tubes, orb) the cleaning of major system components (see ISO/TR 10949).Verification of the cleanliness of assembled systems is covered in ISO/TS 16431.2 Normative referencesThe following referenced documents are indispensable for th
16、e application of this document. For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenced document(including any amendments) applies.ISO 4021, Hydraulic fluid power Particulate contamination analysis Extraction of fluid samples from linesof an
17、operating systemISO 5598, Fluid power systems and components VocabularyISO/TR 10949:2002, Hydraulic fluid power Component cleanliness Guidelines for achieving andcontrolling cleanliness of components from manufacture to installationISO/TS 16431, Hydraulic fluid power Assembled systems Verification o
18、f cleanliness3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.3.1 flushingprocess of cleaning a hydraulic piping system that involves the circulation of turbulent hydraulic system fluidwithin piping system loops to remove,
19、transport and filter out particles that can have been introduced into thesystem during manufacture and build and after maintenance3.2 outflushingunrestricted discharge of sufficient fluid volume to an open container or bucket to remove contamination from adead end in the pipingBS ISO 23309:200723.3
20、visible cleanlinesssurface cleanliness that can be identified visually without magnification3.4 clean work areawork area that is kept free from any activity that produces debris or particlesNOTE Activities such as welding, chipping, cutting, grinding or burning can produce debris and particles, and
21、as aconsequence ought not be carried out in the work area.4 Cleanliness levelThe main purpose of flushing is to achieve the cleanliness level required by the customer or the supplier of thesystem or component. For the case where the required cleanliness level is not stated, Annex A providesselection
22、 guidelines.5 Flushing lines in a hydraulic system5.1 FactorsSome factors to be considered for the achievement of a satisfactory cleanliness level for lines in a hydraulic fluidpower system area) the selection of components that have been cleaned in accordance with ISO/TR 10949,b) the initial cleanl
23、iness of the fitted lines,c) the use of appropriate flushing procedures,d) the selection of a suitable line-mounted filter having a rating capable of achieving the required cleanlinesslevel within an acceptable time period, ande) the establishment of a turbulent flow regime that will pick up the par
24、ticles and transport them to the filter.5.2 System layout5.2.1 It is important for designers of hydraulic systems to plan for system flushing in the design phase. Deadends without circulation shall be avoided. If there is a risk of particulate contamination moving from the deadend to the rest of the
25、 system, then the dead end shall be capable of being outflushed.5.2.2 Circuits shall not be connected in parallel when flushing. Series connection of line sections may beacceptable if turbulent flow can be maintained. Parallel flow paths shall be avoided in piping loops unlessinstrumentation is prov
26、ided to verify an adequate flow rate is present in each parallel flow path.5.2.3 Components that can prevent a high flow velocity being achieved or which can themselves be damagedby high flow velocities or particulate contamination shall be disconnected from the circuit or bypassed. It shallbe possi
27、ble to interconnect each of the circuit line components for flushing.5.2.4 Sampling valves in accordance with ISO 4021 shall be provided at strategic locations.5.3 Component cleanliness levelComponents and assemblies that are fitted into the system should be at least as clean as the specified system
28、cleanliness. Component suppliers should be able to give information regarding component cleanliness levels.BS ISO 23309:200735.4 Anti-corrosion agentsIf the components contain anti-corrosion agents that are not compatible with the system fluid, the componentsmay be flushed using a degreasing agent t
29、hat is compatible with elastomers and the intended system fluid. Thedegreasing agent shall not affect component seals.6 Treatment of lines6.1 Preparation of lines during fabricationTubing or piping to be used as a hydraulic line shall be deburred in accordance with procedures agreed betweenthe manuf
30、acturer and the user. Tubes or pipes with scale and/or corrosion shall be treated in accordance withprocedures agreed between the manufacturer and user.6.2 Surface treatmentTo maintain cleanliness until installation, lines shall be treated with a suitable protection liquid. Corrosion-protection meas
31、ures can be required during storage.6.3 Storing of lines and connectorsCleaned and surface-treated lines and connectors shall be capped immediately with clean caps and stored in aclean, dry place.7 Installation of hydraulic lines7.1 During the installation of hydraulic lines, it is important to avoi
32、d welding, soldering or heating the lines toprevent scaling. If this is not possible, the relevant lines shall be cleaned and re-protected(see ISO/TR 10949:2002, 5.3).7.2 Flanges or recognized connectors should be used. All protection items fitted to lines and components (e.g.caps) shall be removed
33、as late as possible in the installation process (see ISO/TR 10949:2002, 5.3).8 Flushing requirements8.1 General8.1.1 A project-specific document shall be produced to identify the lines that shall be flushed and record thecleanliness level that is achieved.8.1.2 A flushing procedure should be adapted
34、 to the practical conditions. However, certain main criteria shallbe met to ensure that a satisfactory result is obtained.a) The portable hydraulic power pack reservoir shall be cleaned to a level at least matching that of thespecified system cleanliness (see Clause 4).b) The fluid used to fill the
35、system shall pass through a suitable filter see 5.1 d). During filling with hydraulicfluid, air shall not be brought into the system; if necessary, the system shall be topped up and re-bled.c) Pumping equipment shall be located as close as possible to the supply end of piping loops to minimize flowr
36、ate losses.d) Flow-measuring and temperature-measuring devices shall be located near the return end of the piping loop.e) Filters shall be located close to the return end of the piping loop. A supply-side filter may be used.BS ISO 23309:200748.2 Removing particles from internal surfaces8.2.1 For eff
37、ectively removing particulate contamination from hydraulic lines, the main requirement is that theflushing fluid has turbulent flow. Turbulent fluid flow will also ensure transportation of the particulatecontaminants out of the system and to the filters. A fluid with a Reynolds number ( ) greater th
38、an 4 000 shallbe used to flush the system.NOTE If the flushing is done with a fluid with a number less than 4 000, there could be sections of laminar flow withinthe lines.8.2.2 and the required flow rate ( ) can be calculated using Equations (1) and (2):(1)(2)whereis the flow rate in litres per minu
39、te;is the viscosity in square millimetres per second;is the inside diameter of the line in millimetres.8.2.3 It could be difficult to obtain a value of greater than 4 000. should be raised by either increasingthe flow rate or reducing the viscosity. Reduction of viscosity should be used as the prefe
40、rred method forachieving turbulent flow. Viscosity may be reduced by increasing the temperature or by using a compatibleflushing fluid with a lower viscosity.If the fluid temperature is increased, the temperature rise shall be limited so as to ensure that the fluidproperties do not break down or tha
41、t system components are not adversely affected. If a special flushing fluid isused, it shall be compatible with the intended system fluid. The preferred options are to use the system fluid forflushing or a lower viscosity grade of the same system fluid.8.2.4 In a cold environment, the flushing fluid
42、 can suffer from heat loss. In such a case, in order to verify thatis greater than 4 000, the temperature of the fluid shall be checked at the estimated coldest point of thesystem. Flushing shall only be accepted when the lowest temperature measured provides for greater than4 000 (consult the manufa
43、cturers data for the viscosity and temperature of the relevant flushing fluid). Undervery cold conditions, the system shall be insulated to keep the temperature above the minimum necessary toprovide for greater than 4 000.8.2.5 Care shall be taken when considering a reduction in the diameter of the
44、hydraulic lines that thenecessary value is maintained, as this can have an impact on the flushing flow rate or low-pressurecomponents.8.2.6 The use of vibration, high-frequency sound, or a change in flow direction will contribute to a fasterremoval of particles. However, this is a supplement and not
45、 an alternative to turbulent flow.8.2.7 Pressure in the piping system shall be monitored to ensure that it does not exceed the systemsmaximum allowable working pressure.8.3 Filters and separation of particles8.3.1 General requirements8.3.1.1 The filters used for flushing determine the final cleanlin
46、ess level and the clean-up time.ReReRe qVRe =21 220 qV dqV=dRev21 220qVvdRe ReReReReReBS ISO 23309:200758.3.1.2 Choosing a filter with the optimum filtration ratio is important. If filters with a filtration ratio inadequatefor the application are used, situations may arise where the specified cleanl
47、iness level cannot be achieved or isachieved after an extended flushing period.The filtration ratio is determined according to ISO 16889.8.3.1.3 Filters shall have a means to monitor blockage (e.g. a differential pressure indicator). Filter elementsshall be replaced as necessary in order that the pr
48、essure drop is kept within the filter elements operating range.8.3.2 Additional external flushing filters8.3.2.1 Additional filters could be required during the flushing process in order that:a) sensitive components are protected from the ingress of particles (e.g. when used in the suction line topr
49、otect the pump from contamination in the reservoir); the effects of an additional pressure drop should alsobe taken into account;b) particles released from the component are captured immediately (e.g. when a return-line filter is used toprevent the particles from settling in the reservoir),c) the flushing time is reduced.8.3.2.2 Large flushing filters should be used when possible. The smallest acceptable flushing filter shall havea maximum pressure drop through a clean filter element of of the setting of the byp
