1、Designation: E2814 18Standard Specification forIndustrial Woven Wire Filter Cloth1This standard is issued under the fixed designation E2814; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in par
2、entheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONIndustrial metal filter cloth is a special type of woven wire cloth that can be produced in manyspecifications, often proprietary in nature. Sometim
3、es referred to as Dutch weave or Hollander weave,filter cloth can be woven in a variety of metals and is woven with a greater number of wires in onedirection than the other, and utilizing two different wire diameters. This specification covers wovenwire filter cloth for industrial use, which is comm
4、only rated by its micron retention capability. Itspurpose is to introduce standard terms and definitions, to observe common technical considerationsthat a user should be aware of, and to present alternative acceptance criteria based on a desired poresize, or micron retention filtration rating. It sh
5、ould be noted this specification excludes standardindustrial woven wire cloth and sieve cloth from its scope, since these are covered underSpecifications E2016 and E11, respectively, as well as excludes plastic and synthetic filter cloth.1. Scope*1.1 This specification covers the special grade of in
6、dustrialwoven wire cloth, referred to as filter cloth, for generalfiltration including the separation of solids from fluids (liquidsor gases), based on a desired particle size retention. Filter clothcan be made of any primary metal or metal alloy wire that issuitable for weaving.1.2 The values state
7、d in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use.
8、 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.1.4 This international standard was developed in accor-dance with internationally recognized principles
9、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 Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A478 Specification for Chromium-Nickel
10、 Stainless SteelWeaving and Knitting WireA555 Specification for General Requirements for StainlessSteel Wire and Wire RodsE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE1638 Terminology Relating to Sieves, Sieving Methods,and Screening MediaE2016 Specification for Industrial Woven
11、Wire Cloth2.2 SAE Standards:3ARP-901 Bubble-Point Test Method3. Terminology3.1 Definitions:3.1.1 For additional terminology, refer to TerminologyE1638.3.1.2 bubble point test, na capillary flow test method thatmeasures the pressure required to force an air bubble througha filter cloth sample wetted
12、under a test liquid of known surfacetension.3.1.2.1 DiscussionThe pressure is inversely proportionalto the pore size, should be standardized, and the pressure1This specification is under the jurisdiction ofASTM Committee E29 on Particleand Spray Characterization and is the direct responsibility of S
13、ubcommittee E29.01on Sieves, Sieving Methods, and Screening Media.Current edition approved April 1, 2018. Published June 2018. Originallyapproved in 2011. Last previous edition approved in 2011 as E2814 11. DOI:10.1520/E2814-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or
14、contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096, http:/www.sae.org.*A Summary of Changes section a
15、ppears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Prin
16、ciples for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1observed at the first bubble point location is considered theabsolute rating. The test result pressure can be converted to acalculated
17、pore size or micron retention by applying a selectedtortuosity factor.3.1.3 cloth thickness, nthe cross sectional height of thefilter cloth, nominally estimated by adding the warp wirediameter plus two times the shute wire diameter.3.1.4 crimp, ncorrugation in the warp and shute wires.3.1.4.1 Discus
18、sionThe crimp in the wires is formed dur-ing the weaving process, and the tension existing between thewarp and shute wires fundamentally determines the respectiveamount or depth of crimp, which in part establishes thefirmness of the filter cloth. In standard filter cloth the warp wireis tensioned su
19、ch that it only crimps minimally if at all, and theshute wire crimps predominately around the warp wire. Inreverse filter cloth the warp wire is held under reduced tensionas it does crimp around the shute wire, but the shute wireremains predominately straight.3.1.5 cut point, nthe particle size abov
20、e which 97 % of theparticles are trapped by the filter.3.1.6 filter cake (surface cake), nmaterial that is retainedon the filter cloth during processing.3.1.6.1 DiscussionThe filter cake forms and builds up asparticulate is retained, until the increased flow resistance of thefilter cake requires it
21、be removed from the filter cloth, typicallyby back flushing. The deposition of material forming the filtercake can aid in filtration by providing depth filtration, whichresults in a lower micron retention.3.1.7 filter cloth, na special type of woven wire cloth, alsoreferred to as Dutch weave, with a
22、 greater number of wires inone direction than the other, and utilizing two different wirediameters.3.1.8 glass bead test, nmethod for determining the filtra-tion rating of filter cloth using a set of presorted, preciselysized spherical glass beads, passing them through the filtercloth, and examining
23、 the beads passed or captured.3.1.8.1 DiscussionThe largest bead passed is consideredthe absolute micron retention rating.3.1.9 mesh, nnumber of wires or openings per linear inchor 25.4 mm counted from the center of any wire to a pointexactly 1 in. or 25.4 mm distant, including the fractionaldistanc
24、e between either thereof.3.1.10 micron, ncommon filtration reference to a particlesize, properly defined as a micrometre.3.1.11 micron retention, nseparation particle size of thefilter cloth expressed as a diameter in micrometres.3.1.12 micron retention, absolute, ndiameter of the largestspherical p
25、article that will pass through the filter cloth underlaboratory conditions representing the maximum pore size.3.1.13 micron retention, nominal, nsubject to userdefinition, an indication of the average pore size of the filtercloth.3.1.13.1 DiscussionThe nominal rating may refer to: (1)the glass bead
26、or particle size the filter cloth will retain 90 %of by weight; (2) the bubble point pore size when the tenthbubble location appears; or (3) the degree of filtration achievedunder specific process conditions such as operating pressure,concentration of contaminant, and the buildup of filter cake,such
27、 that 94 % to 98 % of all particles of the nominal value willbe retained after a given working period.3.1.14 percent open area, nnot applicable; because of theirregular triangular-shaped opening formed at an angle to theplane of the filter cloth surface, the percent open area isgenerally not a speci
28、fied parameter.3.1.15 shute wires, nwires running the short way of, oracross the cloth, as woven (also referred to as the shoot, fill, orweft wires).3.1.16 types of weaves, n:3.1.16.1 double warp, adjfilter cloth (either plain or twill)in which two warp wires are used instead of one for each warppit
29、ch thus reducing the micron retention of a similar regularsingle-warp wire specification (see Fig. 1).3.1.16.2 plain, adjfilter cloth in which the shute wirespass over one and under one warp wire (see Fig. 2).3.1.16.3 reverse weave, adjfilter cloth in which the warpand shute wires are woven in a rev
30、erse configuration (see Fig.3).3.1.16.4 twill, adjfilter cloth in which the shute wires passover two and under two wires (see Fig. 4).FIG. 1 Double Warp PlainFIG. 2 Plain WeaveE2814 1823.1.17 warp wires, nthe wires running the long way of thecloth as woven.3.1.18 weight per unit area, nweight per sq
31、uare foot forfilter cloth can be approximated (without consideration for thesignificant crimp of the shute wire) by the following equation:Wt/ft25 12Mw12 Dw2/4! !#112Ms12 Ds2/4! !# (1)where:Wt/ft2= weight (lb) per square foot,Mw= mesh warp,Ms= mesh shute,Dw= diameter warp wire,Ds= diameter shute wir
32、e, = density of material (lb/in.3) (0.2836 for stainlesssteel 304), and = constant 3.1416.3.1.18.1 DiscussionThe theoretical mass per unit area canbe similarly calculated with SI units or an approximatemultiplier factor of 4.8824 can be used to obtain kilograms persquare metre.3.1.19 wire diameter,
33、nthe cross sectional size of the wireexpressed in decimal parts of an inch or the metric equivalent.4. Significance and Use4.1 Industrial filter cloth is a specialized product that can bemanufactured in many specifications. The purpose of thisspecification is to (1) introduce standard terms and defi
34、nitionsassociated with wire filter cloth, (2) observe common technicalconsiderations that a user should be aware of, and (3) presentnormal tolerances as well as alternative acceptance criteriabased on a desired pore size, or micron retention filtrationrating. As often numerous specifications may be
35、developed toresult in a common micron retention by varying the weavetype, mesh count, and wire diameters, it is recommended thatthe user consult with their filter cloth supplier regardingspecific filter cloth specifications of interest and include in theirdiscussions durability, pressure drop, and c
36、leaning capabilityrequirements. The purpose of this specification is not tosuggest a limited selection of specifications.5. Filter Cloth Specifications5.1 Filter cloth is woven in a variation of sometimesproprietary parameters based on often common nominal meshcount specifications. This is due to mi
37、nor variations in meshcount and wire diameters used to affect micron retention,porosity, and other factors related to specific operatingconditions, as well as possibly for manufacturing convenience.Therefore, it is not appropriate to provide a comprehensivetable of common filter specifications stati
38、ng constructionrequirements and resulting parameters.5.2 Industrial filter cloth can be woven from a great varietyof metals and alloys. For the purposes of tolerances as woven,the following metals are applicable: brass, nickel again why a minimumpressure is the optimum specification vs. calculated p
39、ore size.6.3.1.4 Further, it should be noted that the same meshspecification can result in different bubble point pressures butnot necessarily due to different pore size (in accordance withARP-901 this can be due to wire roughness, metal chemicalcharacteristics, and a hysteresis effect). Conversely,
40、 the differ-ent geometry of different mesh specifications with similar poresize can yield different bubble point pressures due to differenttest fluid contact angles.6.3.2 Glass Bead Testing7The use of this characterizationtechnique shall specify a cut point (not to be confused withpore size distribu
41、tion) along with the nominal meshdesignation, and acceptance shall be based on conducting aglass bead test on a sample(s) as agreed.6.3.2.1 Properly called gravimetric challenge testing, nar-row size distribution glass microspheres are used to determinethe largest size microspheres that will pass th
42、ru the filter cloth(hence challenging the sample). The process of gravimetricanalysis uses a sample of microspheres that have been preparedand made traceable using National Institute of Standards andTechnology (NIST) certified electroformed sieves, and imageanalysis to check that there is a smooth G
43、aussian distributionwithout peaks or discontinuity of the glass bead sizes.The filtercloth sample is mounted in a sieve frame, weighed, the filtercloth surface covered typically 80 % with a weighed sampleof the calibrated microspheres, shaken using a mechanical,air-jet, or sonic sieve shaker to end
44、point (typically 1 minute),and re-weighed with the retained material. The percentage ofthe microspheres passing is then used to determine the cutpoint from the microsphere sample calibration graph (a cumu-lative graph of weights vs. bead diameters).6.3.2.2 This characterization technique can be high
45、ly accu-rate based on using properly prepared microspheres, and canaccordingly then provide a NIST traceable certification (seeexample Appendix X2). In the absence of a formal test methodstandard for gravimetric challenge testing, the user and sup-plier shall develop agreement for the exact test met
46、hodology tobe utilized. For less than 20 micrometre gravimetric challengetesting, a wet solution of microspheres should be used vs. thestandard dry test method.6.3.3 Geometric Math Model8The filter cloth acceptanceshall be based on manufacturing specific mesh counts and wirediameters within toleranc
47、es agreed with the supplier, that havebeen used in the Tittel and Berndt with Blackmore geometricmath model to predict the pore size. This model can be used topredict the micron retention or separation particle size of anyfilter cloth specification a user and supplier wish to develop,and for compara
48、tive purposes.6.3.3.1 This mathematical model assumes rigid, sphericalparticles that pass through various planes or cross sections ofthe filter cloth, created by the shute wires stretched around thewarp wires and positioned geometrically adjacent to oneanother. The separation particle size is determ
49、ined for theapplicable geometric plane based on the weave type andspecification ratios.6.3.3.2 While five geometric planes of the filter cloth areconsidered (three of interest as the outer two are symmetrical),Plane 3, designated the geometric middle plane of the filtercloth, is the primary plane of interest. Accordingly, the sepa-ration particle size (dTr3) is determined for plain weave withwarp wire to shute wire diameter ratios within the range 1.00to 1.50 (see Annex A1). For twill weave with warp pitch towarp wire diameter ratios greate
