peco facet glossary filtration terms

8/13/2019 Peco Facet Glossary Filtration Terms

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GLOSSARY OF

FILTRATIONTERMS

A BASIC REFERENCE FOR ENGINEERS,PLANT MANAGERS, PURCHASING AGENTS,

INVENTORY PERSONNEL, DRAFTSMEN

AND STUDENTS


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INTRODUCTIONThis glossary defines terms used in the filterindustry and explains how these terms are

applied. Filter Industry is a general term intendedto include such products as filters,

coalescer/separators, pre-filters, clay treators, etc.

Because this list contains many words that may beconsidered colloquial or expressions conined by

equipment manufacturers, it may also be considered as a vocabulary of filter terms. While

many of these terms may have other definitions inother industries or other engineering usages, thedefinitions used herein are limited to the use orapplication as they relate to the Filter Industry.


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abrasion activated clay

ABRASIONMigration of foreign material which enters the uid stream fromsystem components that wear from close tolerances, vibration, or shock.

ABSOLUTEAn arbitrary term used to describe or dene a degree of ltration.The ltration industry uses various methods of determining absolute ratings thatare not necessarily interchangeable. Generally, absolute references 100% removalof solids above a specied micron rating on a single pass basis. See nominal.

ABSOLUTE FILTERIn liquid ltration, absolute is frequently used to implythe size above which no particles will be found in the ltrate, e.g., a one-micronabsolute lter. It has been applied to air lters of high efciency greater than95% against submicron particles but is now less frequently used. Modernterminology prefers HEPA lter (High Efciency Particulate Air), but a better formis probably HESPA (High Efciency Submicron Particulate Air).

ABSOLUTE RATINGThe diameter of the largest hard spherical particle that willpass through a lter under specied test conditions. This is an indication of thelargest opening in the lter element.

ABSORBTo intercept, or drink in. To suck in, as a sponge sucks in water.ABSORPTIONA physio-chemical process in which a substance associateswith another to form a homogeneous mixture presenting the characteristics of asolution.

ACCELERATORTo hasten action. Also used to describe an auxiliary valve tohasten uid action.

ACFMActual Cubic Feet Per Minute. Measured at operating temperature andpressure.

ACIDA large class of compounds which contain the element hydrogen (H+)in its formula which may be replaced by metallic salts. Of primary concern is thedeleterious effect most acids may have on lter medium and housings.

ACIDITYThe quality, state or degree of being acid. In lubricating oils, aciditydenotes the presence of constituents whose concentration is usually dened interms of a neutralization number. The constituents vary in nature and may or maynot markedly inuence the behavior of the uid.

ACTIVATED ALUMINAA highly porous and granular form of aluminum oxidehaving preferential adsorptive capacity for moisture from gases, vapors, and someliquids. May be regenerated for extended use under specied conditions.

ACTIVATED CARBONAny form of carbon characterized by high adsorptivecapacity for gases, vapors, or colloidal solids. The carbon or charcoal is producedby destructive distillation of wood, peat, lignite, nut shells, bones, vegetable orother carbonaceous matter, but must be activated by high temperature steam orcarbon dioxide which creates a porous particle structure.

ACTIVATED CHARCOALSee activated carbon.ACTIVATED CLAYAn adsorbent clay that removes color, odor, tree fatty acidsand surfactants, etc. from oils and hydrocarbons.

A


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activated silica aerosol

ACTIVATED SILICAcolloidal silica dispersed in an aqueous medium toproduce sol. In this condition the silica is considered to be in the active form andif no further precautions are taken polymerization will ensue until the gelationpoint is reached. At this stage silica gel is created, rather than the desirablesol . Gelation may be prevented by copious dilution after the appropriate aging

period, dependent on the mode of preparation. The active sol is a valuable aidto coagulation and the subsequent sedimentation process in the treatment ofwater supplies and aqueous efuents. Prepared by neutralizing the alkali presentin sodium silicate solutions by acids, or salts which yield an acid reaction due tohydrolysis in aqueous solution, and thus precipitate metasilicic acid (H 2SiO 3). Anaging period at this stage results in the active SiO 2 sol.

ACTIVATED SLUDGEBiologically active oc from aeration and settling sewageand/or organic matter.

ADAPTORAn attachment or adjunct to condition an apparatus or componentpart for a use not intended originally. Example: a device used to permit themounting of a cartridge on cartridge mounting plate.

ADDITIVEA material, usually chemical, added to a product to impart new orunusual characteristics or to improve existing characteristics.

ADDUCTTo draw forward; to bring together similar parts.

ADHESIONIntermolecular forces which hold matter together. Also applied tothe sticking together of a particle to a surface, a ber or another particle. The mainfactors affecting adhesion of particles are 1) London-van der Waals forces whichare electrical in origin, 2) electrostatic forces and 3) surface tension due to lms ofmoisture on particles or on the surface. Other factors inuencing adhesion are thenature of the surfaces, surface contaminants, particle size, shape and roughnessand time of contact.

ADHESIVESUsed in the essential bonding process between cylinders ofpleated lter paper and end caps in paper lter element production. Types usedinclude air drying synthetic rubber/solvent/resin mixtures, two part epoxide and/orpolyurethanes and heat curing adherent plastisols.

ADIABATICInsulated and neither heated nor cooled; as in an adiabatic change,wherein a condition is altered without gain or loss of heat.

ADSORBThe physio-chemical phenomenon involved to attract and hold a gas,vapor, or liquid on the surface of a solid, particularly on a nely divided material.ADSORBATEThe material which is adsorbed; i.e., the gas, vapor, or liquidwhich adheres, or is chemically attracted to, the surface of the solid.

ADSORBENTThe material which adsorbs; i.e., the solid which attracts andholds on its surface the gas, vapor or liquid. Also materials added to liquors todecolorize or purify by adsorbing the color or impurity. Fullers earth, activatedcarbon, activated alumina, etc., are all adsorbents.

ADSORPTIONThe natural phenomenon of a gas, vapor, or liquid beingattracted to, and held on, the surface of a solid. To some extent, adsorptiontakes place on any solid surface, but certain materials have sufcient adsorbentcapacity because of the nely divided material to make them useful in suchindustrial applications as the purication and separation of gases and liquids.

AEROSOLA liquid or solid particle suspended in air, gas, or vapor.


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afuent aqueous contaminant

AFFLUENTFluid entering the lter or lter separator. More commonly describedas inuent. Opposite of efuent.

AGGREGATEFluid mixture of concentrated solids to be ltered.AIR ELIMINATORFloat-operated valve to evacuate air or gas from a housing orchamber.AIR-GARDA small three-stage air/gas entrainment lter separator marketed byFacet.

AIR/GASA product line of Facet. Air in this case is restricted to compressed air,vacuum and atmospheric intake lters.

ALKALIA term that applies to the type of compounds which have basicproperties and which will neutralize acids. Some alkaline materials are hydroxides,carbonates, caustics, etc.

ALKYLATIONA petroleum rening process.ALPHA CELLULOSEThat portion or fraction of cellulose which is extracted andpuried by various chemical means to form bers used in the manufacture of nechemicals, pharmaceuticals, ne grade papers, etc.

AMBIENTSurrounding. Example: ambient operating temperature of a housing istemperature essentially the same as that surrounding the housing.AMINEA class of organic compounds of nitrogen that may be considered asderived from ammonia. May be a gas, liquid or solid. All amines are basic innature and will usually combine readily with hydrochloric or other strong acids toform salts.

AMMONIAA colorless gas with characteristic pungent odor. Most ammonia isnow produced by direct combination of nitrogen and hydrogen gases. Present

usage is not restricted to a pure gas or compressed liquid but also includessolutions such as aqua ammonia. Used for refrigeration, fertilizer, chemicalmanufacturing, and many other uses.

AMORPHOUSNon-crystalline, having no determinable form or crystalline form.Solids to be removed by ltration may be amorphous.

AMPCOTrade name for a series of aluminum-iron-copper alloys.ANCHOR BOLT PLANArrangement of mounting devices to hold a housing inposition. Specic location of bolting to anchor a housing.

ANGSTROMA unit of length 10 -10 meter used primarily to express wave lengthsof optical spectra. Abbreviated as A. Also known as tenthmeter.

ANHYDROUSFree from water.APIAmerican Petroleum Institute

API GRAVITYAn arbitrary scale expressing the gravity or density of liquidpetroleum products. The relation between API scale and specic gravity ofpetroleum oil is expressed by the formula:

Degrees API =

APPARENT DIRT CAPACITYThe actual weight of contaminate injected into thelter test system at the time the terminal press drop is reached.

AQUEOUS CONTAMINANTWater contaminant.

141.5Sp. Gr.

131.5


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area attrition

AREAThe available apparent surface exposed to the ow of a uid formaximum utilization. Function of area in ltration is related to initial pressure drop,rate of ow, and solids retention capacity. In many applications, proper utilizationof area of medium produces greater efciency and solids retention. This isaccomplished by pleating of material into an accordion form to produce increased

surface area much greater than in a cylindrical form.ARIZONA TEST DUSTSStandardized air cleaner test dusts classied fromnatural Arizona dust and generally referred to as A.C. Fine and A.C. Coarse testdusts. The nominal particle size distribution of A.C. Fine test dust is:

Size (microns) % by weight 0-5 39 2 5-10 18 3

10-20 16 3 20-40 18 3 40-80 9 3

The nominal particle distribution of A.C. Coarse test dust is:

Size (microns) % by weight 0-5 12 2 5-10 12 3

10-20 14 3 20-40 23 3 40-80 30 3 80-200 9 3

Used also for testing liquid lters, e.g., for hydraulic uids.

AROMATIC COMPOUNDSCompounds related to six-carbon membered ringsas benzene or its derivatives.

ARTIFICIAL CONTAMINATIONPowders used as test contaminants in ltertesting and usually selected to have similar properties and size distribution asthose encountered naturally. See Arizona test dusts.

ASBESTOSA group of impure magnesium silicate minerals which are found inbrous form. Serpentine type is used for insulation linings and gaskets. Amphiboletype is used as lter material or lter aids in chemical applications.

ASMEAmerican Society of Mechanical Engineers. Published code whichgoverns the design of pressure housings.

ASSEMBLYA general term to describe the combination of a number of itemsused to make up a whole. Example: a cartridge mounting assembly for a lterwould include the cartridges and all items needed to install the assembly in thelter housing. Final assembly would be used to name the action of assembling allitems into an end product.

ATMOSPHERIC PRESSUREThe pressure of approximately 14.7 pounds persquare inch exerted at sea level in all directions by the atmosphere.

ATTAPULGUSA vein of mineral clay mined primarily in Georgia and Florida; theactive ingredient in most fullers earth. Activated by specic thermal treatment andground to ne particle size.

ATTRITIONWear caused by rubbing or friction. Produces ne particles thatusually contaminate liquids which surround the point of attrition. Sometimesreferred to as scouring or scoring.


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average particle size basket

AVERAGE PARTICLE SIZEWhen, as a result of experimental observations, thesize distribution of a particulate system has been established on the basis of anytwo of its normal characteristics-number, length, area or volume-the group valuesobtained may be represented by an average value. The relative percentagefrequency curve provides a means of establishing a mode, the most commonly

occurring value; a median, the line dividing the area under the curve into equalparts; a mean, the vertical at the mean value passing through the center ofgravity of a sheet of uniform thickness cut to the shape of the distribution. Fora symmetrical distribution these values coincide, while for slightly skeweddistributions an approximate relationship is:

mean mode = 3 (mean-median).

If it is assumed the particles are all of the same shape then a number of

expressions for mean diameter can be evaluated: Number length mean diameter Number surface mean diameter Number volume mean diameter Length surface mean diameter Length volume mean diameter Surface volume mean diameter Volume moment mean diameter

Generally, the choice of a particular mean diameter is related to the methodused experimentally for size determination. See mass distribution, particle sizedistribution.

AV GASAbbreviation for aviation gasoline used for piston engines.AVOGADROS LAWThe law which states that under the same conditions ofpressure and temperature, equal volumes of all gases contain equal numbers of

molecules. Also known as Avogadros hypothesis. See Boyles Law and CharlesLaw.

BACK PRESSUREIn an air ow, the resistance at any point of the remainderof the downstream circuit or of any nominated sections of the circuit. In liquidltration the back pressure can be due to a hydrostatic head, e.g., pumping froma lter to a tank at a higher level. Back pressure is also applied to keep CO 2 in

solution in the ltration and handling of carbonated beverages.BACKWASHTo reverse ow air, steam, or uid through the medium to effectsolids removal. Sometimes referred to as blowback.

BAFFLEComponent of a housing which constitutes a stage when used;removes liquid and solids by impingement; may be either upstream ordownstream of the basic lter medium. May also be a plate to protect lterelements from the velocity of ow into a housing.

BARREN LIQUORLiquor for cake washing which contains little or no valuableliquor; as barren cyanide solution in gold cake slimes washing.

BASE SUPPORTThe porous support upon which the medium rests.BASKETElement for a basket strainer. A device normally using a screen as itsmedium for removal of coarse bulk solids.

B


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basket strainer Boyles Law

BASKET STRAINERHousing for the removal of coarse bulk solids from liquid,air, or gas; element is a basket covered with a screen of a given mesh.

BATCHThe quantity of material prepared or required for one operation.Example: a batch may be exemplied as a discontinuous process, such as batchprocessing of paint, soap, etc.

BAUM GRAVITYAn arbitrary scale expressing the gravity or density of aliquid. Water is 10 B.

BAUXITEA natural aggregate of aluminum bearing materials, more or lessimpure. Natural hydrated alumina, A1 2032H 20.

BAY HOUSEA air ltering device that removes particulates.BCPA design code for pressure housings based on the manufacturers bestcommercial practice.

BENTONITEA naturally occurring clay containing appreciable amounts ofthe clay mineral montmorillonite. Mined extensively in Wyoming, the Dakotas,Mississippi, Texas, and California.

BEST COMMERCIAL PRACTICEStandard to which a housing may bedesigned by the manufacturer. Indicates the housing has not been designed toASME code.

BETAis calculated by dividing the number of particles entering the lter bynumber of particles exiting the lter. B10 represents the ltration ratio at 10micrometers of the ratio of the upstream to downstream particles larger than 10micrometers. See ltration beta ratio.

BETA EQUALS 75Multi-pass testing has shown that this is beta ratio whichcorresponds to hard spherical particle denition of the absolute lter rating.

BETA FACTORSA system for measuring lters effectiveness by particle size.BLIND SPOTSPlaces in medium where no ltering occurs. Also referred to asdead areas. Opposite of effective area.

BLINDINGWhere ltered-out particles ll the openings in the medium to theextent of shutting off the ow of product; the loading up of the medium so as toreduce capacity. Also referred to as blocking or plugging.

BLOWBACKTo reverse ow air, steam, or uid through the medium to effect

solids removal. Sometimes referred to as backwash.

BLOWDOWNThe action to evacuate liquids or solids from a housing by use ofpressure.

BODYA housing containing the lter medium. Also referred to as a housing.BOIL POINTThe differential gas pressure following the bubble point pressure atwhich gas bubbles are profusely emitted from the entire surface of a wetted andsubmerged lter medium. Also known as foam all over, mass bubble point, openbubble point.

BOMB KITA kit designed for eld use by the manufacturer, Millipore FilterCompany. Contains materials for obtaining and analyzing liquid samples todetermine solid contaminant level.

BOYLES LAWIf the temperature of a given kind of gas is held constant, thevolume of a sample of gas varies inversely with the pressure. See also Avogadroslaw and Charles Law .


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breaking strength canister

BREAKING STRENGTHAverage force required to break a test specimen bytension.

BREAKTHROUGHUsed to describe the passing of solids through the cakebuilt up on a lter medium. Also referred to as the breakpoint.

BRIDGINGWhere particles being removed form an arch over the individualopening in the medium.BTU (BRITISH THERMAL UNIT)A standard measure of heat content in asubstance that can be burned to provide energy.

BUBBLE POINTThe differential gas pressure at which, under specied testconditions, the rst steady stream of gas bubbles is emitted from a horizontal discof wetted lter medium or a lter cartridge when immersed in a liquid.

BUBBLE RINGA device sometimes tted to a pressure leaf lter so that air orother gas can be introduced to the lter tank to bubble through the liquor in whichthe dislodged lter cake will be carried away.

BUBBLE TESTMeasurement of the largest opening in an element bydetermining the minimum pressure required to force air or a gas through theelement while submerged in alcohol or other liquid. Used as a quality controlbenchmark to determine if a surface type separator or lter cartridge meets the

same value as the prototype cartridge.BULK DENSITY RATIORatio of total mass or weight of the material divided bythe volume.

BUNA-NGasket material. A synthetic rubber frequently used for housingclosures, anges, and lter elements.

BURST PRESSUREThe maximum pressure a housing will safely withstand.

BURSTING STRENGTHForce required to burst a housing. Example: burstpressure may be 100 psi, while bursting strength may be 175 psi.BYPASSCondition resulting from the product owing through a housing withoutowing through the medium. Also a ltering system which lters only part of thestream, on a continuous basis. Opposite of full ow.

BYPASS INDICATORIndicator which signals alternate ow.BYPASS VALVEValve to pass the ow around the media or the housing, usuallyactivated at a given differential pressure setting.

CAKESolids deposited on the lter medium during ltration in sufcientthickness to be removed in sheets or sizable pieces. In many cases, cake mayprovide its own lter medium by adding to the surface of medium. Also referred toas discharged solids or residue.

CAKE RELEASEAbility of medium to allow clean separation of the cake fromthe medium.

CAKE REPUDDLINGBreaking cake structure for reformation.CALIBRATING TANKA tank for calibrating capacity to provide volumetric proofof the delivery of liquids by positive displacement meters. Also referred to asmeter proving tank.

CANISTERContainer or mounting mechanism for elements. May be an actual

C


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cap, element center rod

part of and performing a function of the elements, or may be used to hold theelement in position.

CAP, ELEMENTComponent which covers one end of an element and holds theelement in place in the housing. Sometimes called a yoke.

CAP, ENDThe end of many types of lter cartridges. In particular, the shallowannular dish into which the ends of a pleated paper lter cylinder are adhesivelybonded to form a pleated paper cartridge.

CAPACITYVolume of product which a housing will accommodate expressed ingallons or similar units. Also amount which will lter at a given efciency and owrate, expressed in gallons per minute or similar units.

CAPILLARYFine, hairlike tube having a very small opening.

CARRYING BODYLiquid in which the solid particles are suspended. Example:water borne solids.

CARTRIDGEMedium used in a housing to perform the function of coalescing,ltering, or separating. Also referred to as element, media, repack, etc. Made ina specied physical shape, to be mounted by use of hardware designed for thatpurpose.

CATALYSTA substance which accelerates a chemical reaction without itselftaking part in the reaction. Example: alkylation will not take place unless somesubstance such as sulfuric acid is present; such a substance is called a catalyst.

CAUSTICA class or a name given to a group of chemicals, usually causticsoda or sodium hydroxide. A substance which has the power to burn, corrode,or eat away. Used in chemical manufacture, petroleum rening, pulp and paper,detergents, soap, textiles and vegetable oil rening.

CELLULOSEThe preponderant and essential constituent of all vegetabletissues and bers. Basic in the textile and paper making industries. Three typesexist in alpha-cellulose, beta-cellulose and gamma-cellulose. Material used inlter medium is bound by impregnation, usually a phenolic resin. Process ofmanufacture controls the basic weight and pore size to specication. Filter paper,when impregnated with other properties, produces an excellent hydrophobicmembrane which is non-water wetting and is used in the second stage of twostage ltration separation equipment. Ideal cellulose material provides for a varietyof ltration efciencies, low initial pressure drop, high wet strength and solidsretention.

CENTER COREMaterial formed into a tube or cylinder for structural purposesto permit a cartridge to retain its original physical form. May also be the basicmedium, formed with sufcient strength so as to serve the purpose of a centertube. Example: a tube of glass bers may be formed and cured to such a degreethat a center core is not required. Sometimes referred to as a center tube.

CENTER PIPEComponent of a housing which is used as a mount forcartridges. Made with perforated effect to accommodate ow. A center rod isused for the same purpose but is not perforated and does not accommodate ow.

CENTER RODComponent of a housing used for mounting cartridges in thehousing. Usually made of a round bar material. A center pipe may also be usedfor the same purpose but is made with perforated effect and directs ow throughthe cartridge.


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center seal coagulation

CENTER SEALPart which forms seal between two elements when one elementis one the top of another element. May also be called an adaptor.

CENTER TUBEComponent of an element or cartridge which supports themedium at the center of smallest diameter.

CENTIPOISEOne one-hundredth of a poise. A poise is the unit of viscosityexpressed as one dyne per second per square centimeter.CENTISTOKEOne one-hundredth of a stoke. A stoke is equal to the viscosity inpoises times the density of the uid in grams per cubic centimeter.

CENTRAL PROCUREMENTGovernment procedure of combining the activitiesof many buying ofces into one central operation wherein ltering equipment ispurchased for many locations and may be for one or more of the military services.

CHANNELTo cut grooves or lines in or through the solids deposited on themedium, or through the medium itself. Also may be described as a breakthroughin the medium which would result in a bypass.

CHARLES LAWIf the pressure on a given kind of gas is held constant, itsdensity is inversely proportional to its absolute temperature. See Avogadros Lawand Boyles Law.

CHEMICAL POLARITYAn attribute of a chemical, or family of chemicals, whosearrangement of atoms around the nucleus is not symmetrical making them muchmore chemically reactive than symmetrical chemicals.

CHLORINATETo combine chemically with chlorine.CLARIFICATIONFiltration of liquids containing small quantities of suspendedsolids; ltration takes out most of these solids and increases the clarity of theliquids.

CLARITYAmount of contaminates left in a ltered liquid; the absence generallyindicates the liquids to be free of contamination to an unspecied degree.CLASSIFICATIONCondition in which the larger particles settle out below thener ones. Also referred to as stratication. May also be referred to as the action tosort out particles by various size groups or to some other established criteria.

CLAYMedium used in some elements; usually a blend of attapulgas andmontmorillonite clays.

CLAYSLIPClay in a liquid state such as a sludge. May also be clay suspendedin a liquid.

CLEAN PRESSURE DROPDifferential pressure (drop) across a housing,measured in pounds per square inch at rated ow on new elements with cleanproduct.

CLEAN ROOMRoom in which elaborate precautions are employed to reduce

dust particles and other contaminants in the air, as required for assembly ofdelicate equipment.

CLOTHA type of woven lter septum made from natural or synthetic yarns.COAGULANTThat which produces coagulation or agglomeration of suspendedsolids.

COAGULATIONGrowing together of minute particles to form larger ones, whichare called ocs and are easier to lter. Also referred to as occulation.


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coalescer contaminate

COALESCERMechanical device which unites discrete droplets of one phaseprior to being separated from a second phase. Can be accomplished only whenboth phases are immiscible. Requires a tight medium which is preferentiallywettable and, by its nature of being tight, is also a good ltering material. Goodcoalescing permits gravity separation of the discontinuous phase. Coalescing

may be accomplished by only a coalescer cartridge when the specic gravities ofthe two phases are widely separated. As the gravities difference becomes less,the two stage principle is generally required where nely coalesced discontinuousdroplets are repelled by the second stage separator cartridges.

COALESCINGAction of uniting of small droplets of one liquid preparatory to itsbeing separated from another liquid.

CODEGenerally refers to housing design. A standard to which a housingmay be fabricated. Example: the design may meet the requirements of SectionVIII, ASME Code for unred pressure housings. When used in referring to otherstandards, the full code title should be given.

COLLOIDVery small, insoluble non-diffusible solid or liquid particles that remainin suspension in a surrounding liquid. Solids usually on the order of 0.2 or less.

COLLOIDAL PARTICLESGelatinous substance of minute particles whichremain in suspension.

COLOR BODIESForm of deposit which may appear as producing colors. Termfrequently used in the petroleum industry is hydrocarbon color bodies.

COMPATIBILITYCapability of two or more materials or substances to be usedtogether without ill effect. Must be considered when choosing the medium to beused with any uid stream.

COMPOSITE MEDIAMedia made up of more than one material.

COMPRESSIBILITYDegree of physical change in lter cake particles whensubjected to normal pressures. Also a factor when selecting gasket material.CONCENTRATEMaterial to be ltered. Also referred to as feed, inuent, intake,liquor, mud, prelt, pulp, slimes, or sludge.

CONDENSATIONProcess of cooling a vapor below its boiling point in order for itto be liqueed.

CONDITIONINGImproving the ltering qualities of the lter feed.CONLEY WELDTrade name for an epoxy type adhesive.CONSISTENCYDegree of density or rmness, especially of thick liquids. Aproduct of light consistency is almost uid, while a product of heavy consistencyis thick, and in some liquids may be hard.

CONSISTENCY OF FEEDUsually refers to the ratio of solids to liquid in thefeed.

CONTACT TIMEThe length of time an absorbent is in contact with a liquid priorto being removed by the lter.

CONTAMINATEForeign matter in a uid which is accumulated from varioussources such as system dirt, residue from wear of moving parts, atmosphericsolids which settle in an open system. Contaminates tend to discolor a liquid,cause additional wear on moving parts, cause system upsets in process streams,or reduce the efciency of a uid. Water, as well a solid, may be considered a


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continuous phase critical operating pressure

contaminate when the presence of water causes adverse results. The presenceof contaminates, whether liquid or solid, is the basis on which the use of lters orlter separators are sought.

CONTINUOUS PHASEBasic product owing through a lter or lter separatorwhich continues on through a system after being subjected to solids and/or otherliquid separation.

CONVERSIONChange of type of elements in a housing to vary the efciency.May also refer to the adaptor hardware to provide for use of elements incompetitive equipment, sometimes called retrot. In general, refers to thechanging of one type of medium to another type for a specic purpose.

CONVERSION KITMaterials required to convert a housing to the use of anothertype of element or to perform a different function. Example: convert lter to a lterseparator.

CONVOLUTIONUsed to described one pleat of a pleated surface type element,usually in the shape of a V. Also refers to the twisting or coiling of a cotton materialas well as the irregular spiral or screwlike condition of mature cotton.

CONVOLUTIONSTwistings or coilings. Used to describe one complete pleat ofan element.

COOLANTCooling agent used in many operations.COREMaterial used for the center of an element, generally of the wounddesign. May also be called a center tube when used in the coalescer, separator,or other type lter element. May also be a tube of bers formed into an elementwhich has sufcient strength to provide its own center core.

CORROSIONConversion of metals into oxides, hydrated oxides, carbonates,or other compounds due to the action of air or water, or both. Salts and sulphur

are also important sources of corrosion. Removal of solids and water reducesthe effect or speed of corrosion in many cases; and in other cases, corrosioninhibitors are used to reduce the effect or corrosion.

CORRUGATIONSFine ribbing sometimes applied to lter paper followingresin impregnation and before pleating to form a pleated paper lter element.Corrugations which run at right angles to the main pleats help to hold the pleatsapart against the action of differential pressure encountered in use. Discontinuouscorrugation or dimples are sometimes alternately employed.

COUNTUsed in the term particle count to tabulate number and sizes of solids inspecied groups.

CRENELATEDIndented.CRIMPIn bers, the waviness in certain bers, particularly in ne wools andin certain rayon staple bers. The difference in distance between two pointson a yam as it lies in a fabric and the same two points when the yam has been

removed and straightened, and expressed as percentage between the two pointsas the yarn lies in the fabric. In wire cloth , crimp is the corrugations in warp and llwires to lock the wires in place. Sometimes referred to as double crimp.

CRITICAL OPERATING PRESSUREPressure above which ltration orseparation equipment may produce reduced efciency or fail to function properly.


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critical state depth lter medium

CRITICAL STATEUnique condition of pressure, temperature, and compositionwherein all properties of coexisting vapor and liquid become identical.

CRITICAL TEMPERATURETemperature above which a gas cannot beliqueed.

CRYOGENICSField of science dealing with matter at very low temperatures. Inltration, the extremely low temperature negates the use of many media, gaskets,and certain type housings.

CYCLEActual interval of ltration, expressed in units of time; e.g., hours or days.CYCLICALLY or CYCLICLYOperating in cycles.CYCLONELiquid or gas tter using the principle of centrifugal force whichcauses the contaminate to settle to the bottom of the housing without the use oflter medium.

CYLINDRICALHaving round sides, the ends being equal circles. Opposite ofpleated when used to describe elements.

DALTONS LAWIf several types of gas are put into the same container, the totalpressure exerted is the sum of the partial pressures that each type of gas would

exert if it alone occupied the container.D.E.A commonly used abbreviation for diatomaceous earth.DEAD AREASPlaces in medium where no ltering occurs. Also referred to asblind spots. Opposite of effective area.

DEAD HANDIndicator sometimes used on differential pressure gauge to recordmaximum differential pressure reached between settings.

DEAD VOID VOLUMEVolume of voids unavailable to liquid ow.DEFORMABLEUsed to describe suspended solids that extrude into theinterstices of a lter cake and cause rapid lter plugging.

DEGRADATIONWearing down, or reduction in the efciency of medium.DEGREE OF FILTRATIONLevel of cleanliness of a uid, usually measured inmilligrams in a given volume such as quart, liter, gallon, etc.

DEHYDRATIONRemoval of water or hydrocarbon in vapor form from an air orgas; also water from another immiscible liquid. Differs from entrainment removalin that the dew point of a gas stream will be lowered by vapor removal. A form ofpurication.

DELIVERYOpening through which efuent ows, as open delivery press.DELTA ( ) PA commonly used symbol denoting the pressure drop across a lter.

DENSITYCompactness or thickness; ratio of weight of medium to the weight ofan equal volume of ber. In general, mass per unit volume, usually expressed ingrams per cubic centimeter or pounds per cubic foot, or gallons.

DEPTH FILTER MEDIUMFilter medium which primarily retains contaminantwithin tortuous passages, e.g., brous or granular. Retention efciency is achievedby means of a series of low efciency particle captures.

D


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depth type ltration direct reading differential pressure gauge

DEPTH TYPE FILTRATIONFiltration accomplished by owing a uid througha mass lter medium providing a tortuous path with many entrapments to stopthe contaminates. Flow may be cross ow such as from the outside to inside andthen down the center of an element, or from end to end. Certain types of solids, orcombinations of solids, do not lend to surface ltration where depth type ltration

is found to be more suitable.DESALINATIONProduction of fresh (potable) water from sea water, salt orbrackish water by one of several processes, e.g., distillation, ash distillation,electrodialysis or reverse osmosis if salt content is not too high.

DESICCANTDrying agent or medium used in dehydration of air, gas, or liquids.Examples: silica gel, activated alumina, molecular sieve, etc.

DETERGENT OILSLubricating oils possessing special sludge dispersingproperties for use in internal combustion engines. These properties are usuallyconferred on the oil by the incorporation of special additives.

DEWATERRemoval of water from solids.DEW POINTTemperature at which air is saturated with moisture or, in general,the temperature at which a gas is saturated with respect to a condensablecomponent.

DIAPHRAGMAs used on valves, a diaphragm is a exible material whichpermits the movement of internal parts without the loss or redistribution ofpressure in the chamber.

DIATOMACEOUS EARTHSoft, earthy rock composed of the siliceous skeletonsof small aquatic plants call diatoms (algae). Frequently used as material for aprecoat of lter medium. Capable of absorbing 1.5 to 4 times its own weight inwater. Insoluble in acids except hydrouoric, and soluble in strong alkalies.

DIESEL FUELPetroleum product used as fuel for diesel engines.DIFFERENTIAL PRESSUREDifference in pressure between two given points ofa lter, lter separator, etc.

DIFFERENTIAL PRESSURE INDICATORIndicator which signals the differencein pressure at two points.

DIFFERENTIAL PRESSURE SWITCHElectrical switch operated by thedifference between two pressures and often used to give warning of the end of altration cycle.

DIFFERENTIAL RATINGDifferential pressure specied as the maximum anelement will withstand without structural failure.

DIFFUSIONIn cake washing, removing the original liquor around the individualparticles by mixing with the wash liquor.

DIGESTED SLUDGESludge or thickened mixture of water with sewage solids inwhich the organic matter has been decomposed by anaerobic bacteria.DIMENSIONAL STABILITYAbility of a material to retain its original dimensions.DIRECT READING DIFFERENTIAL PRESSURE GAUGEType of pressuregauge which automatically shows the differential pressure reading between twopoints.


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direction of ow divider

DIRECTION OF FLOWDirection in which product ows through element; maybe from inside to outside, from outside to inside, or end to end, depending on thedesign of the element.

DIRT HOLDING CAPACITYVolume of contaminate an element can hold beforereaching the maximum allowable pressure drop. Volume will vary depending onthe size and design of the element and the density of the solid particles. Usuallyreported by weight such as grams or pounds per element. Also called solidsretention or solids holding capacity.

DISC PACK ELEMENTFilter element constructed by packing alternate discs oflter medium and ow distributor plates into a compact cylindrical form.

DISCHARGELiquid that leaves the housing after passing through the medium.May be different from ltrate; e.g., wash water discharge.

DISCHARGE LIQUORLiquid which has passed through the lter. Also referredto as efuent, ltrate, mother liquor, solute, strong liquor, product, clean and dryproduct, etc.

DISCHARGE VALVEValve to allow the efuent stream to ow out of the housing;may be closed by the operation of a pilot valve, in which case product would notleave the housing. Also called a slug valve. Generally used on petroleum productsat terminals and airports.

DISCHARGE SOLIDSSolids deposited upon the lter medium during ltrationin sufcient thickness to be removed in sheets or sizable pieces. Sometimesreferred to as cake or residue.

DISCONTINUOUS PHASESeparated phase or product from the continuousphase. Example: water may be the discontinuous phase when separated from ahydrocarbon, air or gas.

DISCRETEComposed of distinct units; separate from others. Usually referred toin describing the discontinuous phase.DISPERSIONOperation which results in solid or liquid particles entering intosuspension in a uid. Also applied to a two phase system in which one phase,known as the disperse phase, is distributed throughout the other, known as thecontinuous phase.

DISPOSABLEDescribes element which is to be discarded after use andreplaced with an identical element. Same as replaceable. Opposite of reusable.DISSOLVED SOLIDSAny solid material that will dissolve in the liquid that isbeing ltered, such as sugar in water.

DISTILLATECondensed product of distillation, as certain petroleum products.DISTILLATIONProcess of vaporizing a liquid and collecting the vapor, whichis then usually condensed to a liquid. In industry, this process is widely used toseparate the components in a liquid solution. Since every pure compound boilsat a specic temperature, it is often possible to boil off one liquid while most ofthe higher boiling point material remains in its liquid state. It is extremely difcultand sometimes impossible to separate materials in this way when they boil at thesame, or near the same, temperature.

DIVIDERComponent of a housing: metal plate used to create chambers suchas inlet and outlet chambers.


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downstream elongation

DOWNSTREAMPortion of the product stream which has already passedthrough the system; portion of a system located after a lter, lter separator, etc.

DRAIN VALVEValve for draining off material which has been separated froma uid stream. Also a diaphragm type valve that operates as part of a system toevacuate a discontinuous phase automatically.

DROPQuantity of uid which falls into one spherical mass; a liquid globule. Mayalso be described as several to many droplets.

DROPLETMinute drop which mates to form larger drops capable of falling bygravity.

DUAL GRAVITY VALVEFloat operated valve which operates on the interface oftwo immiscible liquids of different specic gravities and which operates to release

one of the liquids.DUPLEX FILTERAssembly of two lters with valving for selection of either orboth lters.

DURO-GARDFacet trade name for pleated paper lter elements which are amember of the extended area family and are interchangeable with competitiveelements of like dimensions. Characteristics: high solids holding capacity, largeltration area, and no unloading characteristics.

DUROMETER (SHORE)Measurement of the resiliency of gasket material.DYNAMIC ADSORPTIONAdsorption process in which there is constant relativemotion between the material being treated and the adsorbent. In most cases,the gas or liquid being treated is made to ow through a xed bed of adsorbent.Example: the drying of annealing gas. The gas is pumped through an adsorberwhere it is dried and then, with the moisture removed, it is pumped into the brightannealing furnace.

DYNEThe amount of force that causes a mass of one gram to alter its speed byone centimeter per second for each second during which the force acts.

EFFECTIVE AREAArea of medium exposed to ow and usable for its intendedpurpose: coalescing, ltering or separating. Opposite of blind spots or dead area.

EFFICIENCYDegree to which element will perform in removing solids and/ orliquids.EFFICIENCY CURVEGraph showing the performance of a lter whenchallenged by specied articial or natural contaminants under controlledconditions. Penetration or efciency may be plotted against particle size atconstant face velocity.

EFFLUENTStream of uid at the outlet of a lter or lter separator. Opposite ofafuent or inuent.

ELEMENTMedium used in a housing to perform the function of coalescing,ltering or separating. Also referred to as cartridge, repack, etc.

ELEMENT CAPComponent which covers one end of an element and holds theelement in place in the housing. Sometimes called a yoke.

ELONGATIONDeformation caused by a tensile force, expressed as apercentage of the original length.

E


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elutriation excelsior

ELUTRIATIONWashing of suspended solids in sludges.EMISSIONSGases and/or particulates discharge into the environment, usuallythe atmosphere.

EMULSIFICATIONDispersion of one substance in the form of minute dropswithin another substance.EMULSIONDispersion of ne liquid particles in a liquid stream which do notnecessarily dissolve in each other but are held in suspension. Many emulsionsmay be broken by coalescing if the liquids are immiscible. Emulsion stabilizersmodify the surface tension of the droplets which makes coalescing difcult, if notimpossible.

EMULSION SEPARATIONChemical methods of emulsion separation areregularly employed to remove the oil phase from spent emulsion cutting oils, priorto disposal. Typical treatment is by dosing with a solute of a divalent or trivalentmetal. Thermal, electrical and physical methods are also used. See coalescence.

ENCAPSULATEDProcess in which a material is coated or covered with aplastic lm or sheath.

END CAPSComponents adhered to ends of an element with adhesive or byother means to contain medium in the form designed for the element.

END LOAD RATINGMaximum specied axial force which can be applied to theend of a lter element without causing permanent deformation or seal failure.

END POINTFinal objective or, in petroleum distillation, temperature at whichdistillation ceases. Used to describe terminal pressure at which point further useof elements is not recommended. Term may also be used in ltration to describepoint at which a marked color change is observed, indicating that no morereagent is to be added.

END SEALBond between the end cap and the lter medium. In cartridges ofpleated paper construction this is frequently an epoxide, polyurethane or nitrile-phenolic adhesive. Also refers to the sealing device which seals the end cap of acartridge to its housing.

ENTRAINED WATERDiscrete water droplets carried by a continuous liquid orgas phase when water is immiscible with the liquid. May be separated from thecontinuous phase by coalescing and gravity separation. Usually picked up in a

system by condensation or a water washing used in process.ENTRAINMENTMist, fog, or droplets of a liquid which is usually considered tobe a contaminate when used in the ltration industry.

EQUALIZING LINEA connection to equalize the vacuum or pressure at twoseparate points.

EQUILIBRIUM LOADINGMaximum loading for a given temperature, pressure,and concen-tration. Also used to describe an equality of distribution on thesurface of lter medium.

EUTECTICCharacteristic of a mixture having the lowest possible melting pointof two or more constituents which melt completely at a denite temperature toform a single liquid.

EXCELSIORWood type frequently used as coalescing medium for lightproducts and bulk lter. Selected Aspen type excelsior with selected strandthickness and average length is packed into a cylinder, generally for end-to-endow.


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Excel-So lter coalescer

EXCEL-SOTrade name of the original products sold by Warner Lewis Company,generally describing excelsior packed separators.

EXTENDED AREAFamily of pleated cellulose lter cartridges marketed byFacet. By pleating, the available surface area is increased substantially to providefor greater ow, increased efciency, and solids retention capacity. Closelycontrolled manufacturing processes provide for specied basic weight, pore size,and wet strength. Use of different specications provide for varying efciencies toprovide for a wide variety of applications.

FEDERAL STOCK NUMBERIdentication number assigned by the U.S.Government to code the specic descriptions of items purchased for their stock;number is preceded by letters FSN.

FEEDMaterial to be ltered. Also referred to as concentrate, inuent, intake,liquor, mud, prelt, pulp, slime or sludge.

FELTFabric built up of the interlocking of bers by a combination of mechanicalwork, chemical action, moisture and heat. Frequently used as lter medium, sometypes of which have been adapted to high temperature applications for air or gas.

FIBERFundamental unit comprising a textile raw material such as cotton, wool,etc.FIBER MIGRATIONCarry-over of bers from the media used in coalescer,separator, or lter cartridges into the efuent. More denitive than media migrationsince ber migration is qualitative.

FIBERGLASSTrade name for a variety of products made of, or with, glassbers.

FIBERGLASSTerm used to describe a variety of products made of, or with,glass bers, See glass ber.

FILM STRENGTHProperty of a lubricant which permits it to resist beingruptured or broken when under pressure between two metal surfaces.

FILTERTerm generally applied to a device used to remove solid contaminatefrom a liquid or gas. A lter, as referred to in the industry today, is limited to adevice which removes solid contaminates only. If a device is used to remove solidand liquid contaminates, it is referred to in general terms as a separator, lterseparator, or entrainment separator. The term lter is sometimes erroneously usedto describe the medium used inside the housing or lter case, but the correct useshould be lter element, cartridge, etc.

FILTER AIDSubstance of low specic gravity which remains in suspensionwhen mixed with the liquid to be ltered. It should be porous and must bechemically inert to the liquid being ltered. Increases ltering efciency andmaintains cake porosity.

FILTER COALESCERSingle stage, horizontal housing for coalescing andseparating one immiscible uid from another and the removal of solids. Generallyrecommended for use where continuous phase has a light gravity. Available withvarious efciencies.

F


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lter effect ltration beta ratio

FILTER EFFECTGradual increase of lter resistance.FILTER MEDIUMThe porous material mounted on a plate or frame whichseparates the solids from the liquids in ltering. Also referred to as lter cloth, lterplate or septum.

FILTER MONITORWater absorbent lter element which will continuouslyremove dirt and water from aviation fuel.FILTER PAPERA permeable web of randomly oriented bers, generallycellulose (i.e., wood pulp, cotton) or glass ber is formed from water draining froma carefully prepared suspension of these bers fed to a continuously traveling,endless belt of wire mesha paper making machine. The preparation and type ofber controls the permeability within any one thickness and weight per unit areaof grade. Various grades are available with these variations and also with resinaddition to give strength to the paper when wet. A further variation arises with acrepe nish whereby the effective area of paper for a given weight is considerablyincreased. A wide range of lter papers is available commercially for the removalof particles from liquids and gases.

FILTER PLATEThe porous material mounted on a plate or frame whichseparates the solids from the liquids in ltering. Also referred to as lter cloth, ltermedium or septum.

FILTER SEPARATORHousing which removes solids and entrained liquid fromanother liquid or gas. Uses some combination of a bafe and/or coalescer, lter,or separator element. May be single-stage, two-stage, or single or two-stage withprelter section for gross solids removal. Common application is the removal ofwater from gas or another immiscible liquid. General reference to term impliesthe equipment is capable of both ltration and separation to specic degrees ofefciencies.

FILTER SYSTEMThe combination of a lter and associated hardware requiredfor the ltration process.FILTERABILITYEase or difculty of ltering.FILTERS, BULK TYPESimilar to depth type lters; however, the density is notgraded and therefore the reproducibility of the ltration varies.

FILTERS, DEPTH TYPESee depth type ltration.

FILTERS, EXTENDED AREASee extended area.FILTERS, INERT TYPEDesigned to remove insoluble contaminates; all ltersexcept the absorbent and adsorbent types can be generally considered inert.

FILTERS, SURFACE TYPEUsually constructed of pleated, impregnated paperand/or a combination of paper and other media, such as glass bers. Opposite ofdepth type. See extended area.

FILTRATELiquid which has passed through the lter; uid that has beenseparated from the solids in the slurry being ltered. Also referred to as dischargeliquor, efuent, mother liquor, solute, or strong liquor.

FILTRATIONProcess of removing solid particles from liquid or gas by forcingthem through a porous medium.

FILTRATION BETA RATIOThe ratio of number of particles greater than a givensize (n) in the inuent uid to the number of particles greater than size (n) inefuent uid.


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ltration rate Frazier permeometer

FILTRATION RATEThe volume of liquid that passes through a given area oflter in a specic time. Usually expressed as gallons per square foot per minute(or hour).

FINESPortion of a powder like material composed of particles smaller than aspecied size.

FIRE POINTLowest temperature at which a liquid evolves vapors fast enough tosupport continuous combustion; usually close to the ash point.

FLASH DISTILLATIONOperation wherein the liquid is vaporized immediatelyon entrance to the housing.

FLASH POINTLowest temperature at which a combustible liquid will give off aammable vapor that will burn momentarily.

FLOAT CONTROLFloat operated pilot valve which controls other valves orthe opening of an orice; generally used for the elimination of the discontinuousphase; operates on the interface of two immiscible liquids. In the case of air orgas would operate on the surface of a liquid.

FLOATING SCRAPERBalanced scraper which, with minimum pressure, followsthe contour of a drum.

FLOCCULATIONGrowing together of minute particles to form larger ones,which are called ocs and are easier to lter. Also referred to as coagulation.

FLOWViscous ow (also known as streamline or laminar) is characterized bythe viscosity of the uid controlling the relationship between pressure and itsvelocity; with turbulent ow the relationship is controlled by inertial factors. Forviscous ow in ducts Reynolds number is less than 2,000 and for turbulent owgreater than 4,000. See laminar ow.

FLOW RATERate at which product is passed through a housing or system;generally expressed as gallons per minute, barrels per hour, barrels per day,actual or standard cubic feet per minute, hour, day, etc. Same as rate of ow .

FLOW RESISTANCEResistance offered by lter medium to uid ow; thepressure difference required to give unit ow of a uid of unit viscosity through aunit cube of lter medium. See also resistance ventilation lter.

FLUIDTerm used in ltration and separation to include liquids, air or gas as ageneral term.

FOGCondensed water, hydrocarbon, or other liquids which are visible to thenaked eye.

FOUR-STAGEDesign for entrainment separators for use on air or gas, marketedby Facet, which contain a prelter section ahead of the coalescer and separatorcartridges to remove gross solids. Bafe before prelter cartridges removes coarsesolids and free liquid by impingement. Impingement bafe and prelter sectionpermit extended use of Facet two-stage efciency on compressed air or gas.

FRACTIONATION TOWERTower wherein rising vapors meet descending liquid.The lower boiling liquids tend to pass on to the condenser, and the higher boilingphases remain as liquids.

FRAZIER PERMEOMETERPorosity testing device. The normal measurementis the air ow in CFM passed through one square foot of fabric at 1/2 waterpressure. Fabrics with rating of 1 to 10 CFM are considered very tight, whereascloths that test at 450 to 500 CFM are extremely porous. The test is used onwoven and non-woven materials.


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free board glass ber

FREE BOARDClear space between top of liquid and rim of housing.FREEZING POINTFor a pure substance the freezing point or melting point is :he temperature at which the liquid and solid are in equilibrium with one another;i.e., at a higher temperature the solid will melt and at a lower temperature theliquid will solidify. Varies with the composition of the liquid.

FRIABLEEasily crushed or crumbled.FRICTIONResistance created by the surface of one object moving over thesurface of another due to the interlocking of minute projections from the surfaces;this is called solid friction. If a lubricant is introduced between the two movingsurfaces uid friction replaces solid friction.

FUEL-GARD Trade name for a small, compact two-stage lter separatormarketed by Facet for use on liquid/liquid separation. Permits the use of highlyefcient medium developed for larger industrial applications on low ow rates.

FUEL MONITORHousing which monitors the cleanliness of product streamsand shuts off all ow when water or solids contamination reaches predeterminedconcentration; moisture-sensitive elements trap contaminates and increasedifferential pressure to activate shut-off diaphragm.

FUEL WETTABLECapable of accepting liquid fuels. Opposite of nonwettable.

FULL FLOWProduct ow through the housing at the rate for which the housingis designed to operate. Also refers to all product passing through medium.Opposite of a bypass lter which is designed to lter only a portion of the streamat a higher efciency on a continuous basis.

FULLERS EARTHMedium used in some elements, usually a blend ofattapulgus and montmorillonite clay. A nely divided hydrous aluminum silicate.See attapulgus.

FUSESee lter monitor .

GASState of matter in which molecules move freely causing matter to expandindenitely, occupying the total volume available. Denition sometimes includes areference to critical temperature, i.e., temperature above which liquefaction doesnot occur by pressure.

GAS SCRUBBERHousing designed to knock out liquid and solid contaminatesby impingement on a series of bafes or demister pads. Accomplished by drasticreduction of velocity as the gas enters the scrubber. Entrainment separationwould expand the general use of the term to include mechanical cartridge typeseparators.

GASEOUS STREAMStream containing gas, either pure or mixed with a liquid.GASKETMaterial inserted between contact surfaces of a joint to ensure auid-tight seal. Although invariably softer than surfaces with which it is in contactit should not form a permanent bond. Constructional material is dependent on thetemperature, pressure and chemical nature of the conned uid.

GELATINOUSUsed to describe suspended solids that are slimy anddeformable, causing rapid lter plugging.

GLASS FIBERProper reference to a brous material made from glass that iscommonly used as a lter and separator medium. May be used in blanket or tube

form and, due to the random dispersal of the bers, makes good lter medium.

G


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glycol haze

Are hydrophilic (water wettable) and perform the function of coalescingimmiscible liquids for separation. May be used effectively on compressed air, gas,or liquids which are acidic but only slightly caustic. Also referred to as berglassor Fiberglas.

GLYCOLGeneral term for a family of alcohols; clear, colorless, and soluble tovarying degrees in water, alcohol, ether, benzene, etc. Has a wide range of usagesuch as coolants, antifreeze and processes. Refer to specic type for furtherdetails.

GPDGallons per day.GPHGallons per hour.GPMGallons per minute.

GRAVITYRelationship between the weight of a material and the weight of anequal volume of water. In the United States this relationship is expressed in termsof API gravity, Baum gravity or specic gravity.

GRAVITY FILTERFilter in which the driving force for ltration is providedsolely by the head of liquor above the lter medium (i.e., not employing pressureor vacuum to give a high differential pressure). Gravity lters often handlecompressible materials or materials in the form of akes which would pack down

and become impervious under high differential pressure.GRAVITY SEPARATIONSeparation of immiscible phases resulting from adifference in specic gravity by coalescing.

GREASE FILTERAssembly consisting of either a coalescing section or anadsorptive section, or both. The former usually formed from knitted wire an/orglass ber and the latter employs activated carbon.

GROOVED COUPLINGClamp-like device with tongue-like edges which t intogrooves; forms a seal when secured. Commonly called by trade name Victaulic.

GROSS SOLIDSDescribes what may be considered an abnormally heavy solidload.

GROSS WATERDescribes what may be considered an abnormally heavy waterload.

GSFMAbbreviation for gallons per square foot per minute. Also GSFH for hour.GURLEYTerm derived from name of manufacturer of permeometers,densitometers, and other instruments which use air to measure porosity, densityand stiffness of paper. It is also possible for Gurley equipment to be used onporous or permeable material other than paper. Gurley instruments are used byTAPPI, the association of paper manufacturers. Porosity ratings are given in thenumber of seconds taken for 300 cc of air to pass through one square inch ofmaterial. Frazier and Gurley numbers are not convertibleno specic Fraziernumber equals a certain Gurley number. Frazier numbers are possibly moresignicant in that they reect porosity specications.

HAZEFine suspension of smoke or dust having some effect on the visual range.An opalescent or a very ne suspension in a liquid, especially in a beverage, e.g.,wine, is referred to as a haze.

H


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head gasket impingement

HEAD GASKETGasket seal at the main closure of a pressure housing. Usuallythe seal used between two anges. Generally, either a at gasket or o-ring.

HEAD LIFTDevice for raising head of a vertical pressure housing to permitaccess to interior of housing.

HEAT OF ADSORPTIONHeat released when a substance is adsorbed;equivalent to the energy which the adsorbate must give up in going from itsnormal energy state to the lower energy state it has when adsorbed. The heatdepends on the adsorbate and adsorbent.

HEAT OF VAPORIZATIONHeat which must be put into a liquid to vaporize it atits boiling point.

HEEL(1) The liquid left in a lter shell at the end of a cycle; (2) The precoat lefton R.V.P.F. at end of its cycle.HOLDING CAPACITYRefers to the amount of solids, particulate or foreignmaterial one or more elements is capable of retaining up to the terminal ormaximum differential pressure. Also can refer to volumetric holding capacity ofeither a solid or a liquid.

HOMOGENEITYUniformity of particle size and distribution of a solid in theproduct.

HOOKDevice to aid in the mounting of elements held in position by theextension spring.

HYDROCARBONAny one of a large number of compounds composedprimarily of elements carbon and hydrogen. As they increase in molecular weightand boiling point, they may be respectively gases, liquids or solids.

HYDROPHILICWater accepting or water wetting. Having an afnity for water.Capable of uniting with, or dissolving in, water. Effective coalescing requiresmedium to have hydrophilic characteristics causing free or entrained water tocommingle into droplets which, when mated with other droplets, form into dropswhich separate by gravity. Opposite of hydrophobic.

HYDROPHOBICNon-water wetting. Having an antagonism for water. Notcapable of uniting or mixing with water. Hydrophobic features are induced in theprocess of cellulose manufacture. Opposite of hydrophilic.

HYDROSTATIC TESTTest conducted with either air, water or other uids at agiven value over design pressure, to prove the structural integrity of a pressurehousing.

IDInside diameterIFTInterfacial tension

IMHOFF TANKTank for settling sewage and digesting sludge, having uppersedimentation chamber with sloping oor leading to slots through which solidssettle to digestion chamber.

IMMISCIBLEincapable of being mixed; insoluble; opposite of miscible.IMPINGEMENTProcess of removing liquid or solid contaminate from a streamof compressed air or gas by causing the ow to impinge on a bafe plate at ahigh velocity. Contaminate falls off by gravity into a large quiescent sump area to

prevent the contaminates from being picked up a second time by the velocity ofthe stream. May also be used on liquid streams to separate solid contaminates.

I


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in situ interstices

IN SITUIn its original place.INERTInactive chemically or physically.INFLUENTStream of uid at the inlet of a lter or lter separator. Same asafuent. Opposite of efuent.

INHIBITORCompounds or materials that have the effect of slowing downor stopping an undesired chemical change such as corrosion, oxidation, orpolymerization. Addition of certain types of inhibitors change the interfacialtension of a petroleum product, which may reduce the coalescing efciency ofsome medium. Reduced interfacial tension between two liquids causes a tighteremulsion more difcult to break up by coalescing.

INITIAL PRESSURE DROPLoss in differential pressure between two pointsupon the start of ow through a housing using new elements.IN-LINEApplied to mixing and conditioning, in-line means the mixing of liquidswith liquids or solids with liquids, or suspensions of solids in liquids with liquids,within a pipework system using metering units and automated control, whicheliminates the requirement for separate storage tanks and mixing compartments.

IN-LINE FILTERFilter or strainer arranged as a continuous ow unit in a pipelineor similar location.

INORGANICNot formed from living substance; substances which do notcontain carbon as a major constituent.

INSIDE-OUTFlow of product from inside to outside of element.INSOLUBLEIncapable of being dissolved in a uid; opposite of soluble.INTAKEMaterial to be ltered. Also referred to as concentrate, feed, inuent,liquor, mud, prelt, pulp, slimes, or sludge.

INTERCHANGEABLEOne particular element which may be used in place ofanother particular element. Dimensions of both must be equal. Element beingsubstituted frequently has more desirable characteristics than Element which itreplaces. Refers primarily to dimensional interchangeability and must be for thesame general applications.

INTERFACESurface over which continuous phase and discontinuous phaseare in contact.

INTERFACIAL TENSIONMeasure of miscibility or solubility of the continuousand discontinuous phases. Increases as miscibility or solubility decreases. Seeinhibitors for effect on coalescing.

INTERLOCKFacet patented device that is a fail-safe device to preventunmonitored fuel from bypassing the elements.

INTERPLEATPleating of two or more lter media into an element, such as glass

bers and cellulose.INTERSTICESSpaces or openings in a medium. Also referred to as poresor voids. Usually refers to those voids contained in adsorptive media such ascarbon, Fullers Earth, etc. Available area for adsorption on or within a particlethen must take into account not only the surface area but also that area within theparticle due to the interstices or voids.


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interstitial life expectancy

INTERSTITIALPertaining to the openings in a medium.IONElectrically charged atom or group of atoms, formed by the gain or loss ofelectrons.

ION EXCHANGEReversible chemical reaction, usually between a solid and aliquid, in which ions may be interchanged.I.P.The Institute of Petroleum.ISOKINETIC SAMPLINGFluid owing in a duct is sampled isokinetically whentaken through an upstream facing sharp-edged probe so that the velocity into theprobe is identical with the undisturbed free stream velocity at that point. Isokineticconditions are vital for accurately sampling solid or liquid particles above a 5micron diameter from gas streams but may be less important for liquid streams.

Sampling non-isokinetically may produce errors in the weight concentration andsize distribution of collected particles, depending on the density, shape and sizeof the particles and on the density, viscosity and velocity of the owing uid.

ISOTHERMA constant temperature curve.ISOTROPICHaving same properties in all directions.

JET FUELPetroleum product used as fuel for jet engines.

KARL FISHERAnalytical method of determining amount of water present in asample by titration.

KEROSENEPetroleum liquid used as fuel, or for heating purposes.KIESELGUHRFinely divided siliceous material similar to diatomaceous earth,but usually with more impurities.KNIFE EDGE PLEATSharply dened creases at the outer cage of a pleatedelement.

KNIFE EDGE SEALNarrow, pointed ridge on the sealing surface of an end cap,center seal, or cartridge adaptor which provides a seal by biting into the cartridgegaskets.

L-TYPE FILTERCartridge lter in which the inlet and outlet port axis are at rightangles and the lter elements axis is parallel to either port axis.

LACQUERNatural or synthetic resin which is dissolved in a suitable solventsuch as hydrocarbon oil rich in aromatics. When applied, the oil solventevaporates, leaving behind a lacquer lm.

LAMINAR FLOWTerm synonymous with streamline ow and viscous ow. Aow regime in which the ow characteristics are governed mainly by the viscosityof the uid.

LEAFAny at lter element that has or supports the lter septum.LIFE EXPECTANCYAmount of use which may be expected from an elementbefore it must be replaced; will vary according to elements characteristics,operating conditions, and condition of inuent.

J

K

L


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line size mass transfer rate

LINE SIZESize of line used to carry the product in a system, such as a six-inchline.

LIQUIDProduct stream in liquid ltration and liquid ltration separation. Alsomay be the material to be removed by a liquid or gas entrainment separator.

LIQUID LEVEL CONTROLGenerally a oat-operated control operating off theinterface of two liquids for the purpose of evacuating one of the liquids from thehousing after separation. In air or gas, it would operate off the surface of the liquid.

LIQUID LEVEL GAUGEGauge by which the interface of two immiscible liquidscan be viewed, generally in an accumulator sump. May also be called a levelgauge or interface gauge.

LIQUORMaterial to be ltered. Also referred to as concentrate, feed, inuent,intake, mud, prelt, pulp, slimes, or sludge.LITER1.057 quarts. Used as a volumetric standard to analyze liquids for wateror solids content.

LOCK UPDevice that will lock either a column, elements or the body of ahousing in place.

LOW INTERFACIAL TENSIONWhere the interfacial tension of one liquid overanother liquid would be less than 25 dynes/cm at 70F. See inhibitor for effect oncoalescing.

LOX CLEANINGProcess of cleaning for liquid oxygen service. Generallyknown as a process of degreasing or making a component completely free of anyhydrocarbons and/or foreign materials.

LUBRICATIONSubstituting uid friction for solid friction by inserting oil betweentwo moving parts.

LVMLow volatile material. See attapulgus.

MAGNETITEIron ore fully oxidized (Fe 3O4) and naturally magnetic.MAIN CLOSUREClosure through which the housing is serviced when there ismore than one opening into a housing.

MALE MOUNTING CAPDevice which allows elements to be mounted throughan opening in a tube sheet. Normally removed with the cartridge. Used primarilyin conversion kits.

MANIFOLDA pipe or assembly into which the lter elements are connected toform one common discharge for the ltered product.

MARTINS DIAMETERStatistical diameter used in particle size analysis; themean length of line, parallel to the microscope traverse, dividing each particle intotwo equal areas.

MASSMatter contained by a body, regardless of its location.MASS DISTRIBUTIONRelative frequency distribution by mass within a particlesize distri-bution. Sometimes presented as cumulative percentage undersize. Seeaverage particle size.

MASS TRANSFERMovement of matter.MASS TRANSFER RATEMeasurement of the movement of matter as a functionof atoms, etc.

M


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matter micron

MATTERMaterial substance of which an element, elements, or mass iscomposed. In this use does not refer to cartridge elements.

MAXIMUM ALLOWABLE PRESSURE DROPMaximum pressure differential ofa housing under specied product and ow condition.

MAXIMUM DIFFERENTIAL PRESSUREHighest pressure differential which anelement is required to withstand without structural failure or collapse.MAXIMUM OPERATING PRESSUREMaximum pressure allowed in the system.MEAN EFFICIENCY RATINGA measurement of the average efciency of a ltermedium using the Multi-Pass Test where the average ltration (BETA) ratio = 2.0.

MEDIAThe material that performs the actual separation of solids from liquids.Sometimes erroneously used to mean septum.

MEDIA MIGRATIONCarry-over of bers from lter and/or separator elements,or other lter material into the efuent. Less denitive than ber migration and isquantitative.

MEDIUMPrincipal component of an element. Material of controlled pore sizeor mass through which a product is passed to remove foreign particles heldin suspension or to repel droplets of coalesced water; or a material withoutcontrolled pore size such as glass ber mats which contribute to ltration,coalescence, or separation of two immiscible liquids.

MEMBRANEMedium through which the liquid streams are to be passed orexchanged. Normally associated with ion exchange media such as dialysis,osmosis, diffusion, etc., although lter paper itself could be classed as amembrane.

MEMBRANE FILTERThin permeable lm of inert polymeric material castin such a way from a mixture of solvents so that the size, number and shape(tortuosity) of the pores is controlled. Widely used in bacterial ltrationsolutionsterilizingin the medical eld. In multiple units they are used industrially inbeverage ltration and preparation of very pure water, etc. Can be in cylindricalcartridge form. Fine grades used in ultraltration, reverse osmosis and dialysis.

MESH (WIRE CLOTH)Number of openings, or fractions of openings, in a linealinch of wire cloth. Where the fractional part of an inch is specied, for example1/2 mesh or 1/2 mesh, the term is understood to mean the measurement from the

center of one wire to the center of the adjacent wire. Term should not be confusedwith clear openings or space.

METER PROVING TANKTank for calibrating capacity to provide volumetricproof of the delivery of liquids by positive displacement meters. Also referred to ascalibrating tank.

MICROMETEROne millionth part of a meter. A standard SI unit.MICRONShort unit of length in the metric system. One millionth of a meter, 10 -4 centimeter, 10 -3 millimeter, or 0.000039 of one inch. Used as a criterion to evaluatethe performance or efciency of lter medium or to describe the condition of eitherthe inuent or efuent. Usually stated in terms of being either absolute or nominal.Nominal micron rating is generally taken to mean that 98% of all particles overa given micron value have been removed by specic medium. Absolute micronrating is generally taken to mean that all particles over a given micron value havebeen removed. Naked eye can see a particle 40 microns or larger.


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microorganisms motivating force

MICROORGANISMSLiving bodies that can be seen only through a microscope.MICROSCOPE COUNTUse of a microscope for the estimation of mean particlesize within a selected size range, by the use of a calibrated scale, graticule, orother aid. To avoid serious error some 500 to 600 counts, or observations, shouldbe made.

MIGRATIONContaminant released downstream of a lter. Built-in dirtmigration-migration composed of foreign materials introduced during handling,storage and manufacture; Contaminant migrationmigration due to unloading.Media migrationmigration composed of the materials making up the lter media.

MILLILITEROne thousandth of a liter, equal to approximately one cubiccentimeter.

MISCIBLECapable of being dissolved, soluble. Opposite of immiscible.MISTVisible water or hydrocarbon vapor; oating or failing in ne drops.MIXINGProcess of intermingling bers from different bales or lots to produce auniform mixture of all. Usually implies the use of only one kind of ber, while theterm blending is usually used for combinations of different bers, colors, etc.

MMSCFDMillion standard cubic feet per day.

MMSCFHMillion standard cubic feet per hour.MMSCFMMillion standard cubic feet per minute.MOLEUnit quantity in chemistry. Amount of a substance in grams (gram mole)or pounds (pound mole) which corresponds to the sum of the atomic weights of allthe atoms appearing in the molecule. Sometimes referred to as a mol.

MOLECULAR SIEVEZeolite, natural or synthetic, or similar materials whoseatoms are arranged in a crystal lattice in such a way that there are a largenumber of small cavities interconnected by smaller openings or pores of preciselyuniform size. Used as drying agents for some liquids or gases as well as for otherabsorptive applications. May be regenerated for extended use under speciedconditions.

MOLECULAR WEIGHTSum of the atomic weights of all the atoms in amolecule. Sometimes referred to as mole weight or mol weight.

MONITORSee lter monitor .MONO FILAMENTSingle, large continuous lament of a synthetic ber.MONTEJUSClosed pressure tank partially lled with a uid mixture which isforced out by gas pressure on its surface.

MONTMORILLONITESoft mineral commonly found in bentonite; becomes mudlike when wet without expanding.

MOTHER LIQUORLiquid which has passed through the lter. Also referred toas discharge liquor efuent, ltrate, solute, or strong liquor.MOTIVATING FORCEThat which causes the coalescing, ltering or separatingaction to take place.


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MS NPT

MSMilitary Standard. Prex to government-assigned numbers indicatingstandardized items to military specications.

MSCFDThousand standard cubic feet per day.MSCFHThousand standard cubic feet per hour.

MSCFMThousand standard cubic feet per minute.MUDMaterial to be ltered. Also referred to as concentrate, feed, inuent,intake, liquor, prelt, pulp, slimes, or sludge.

MUD SUMPArea of a horizontal housing, located upstream of the media, forthe collection of solids falling out by gravity prior to going through the coalescingmedia, where gross solids are present in the stream.

MULLEN BURST TESTMeasurement of the force needed to burst a givenarea of paper or cloth, under uid ow conditions, and usually expressed as thepressure in inches of water that will burst a 2 diameter test specimen.

MULTI-FILAMENTA number of continuous ber strands that are twistedtogether to form a yarn; used in weaving lter cloths.

MULTI-PASSThis test system is designed to be representative of a typicalhydraulic and lubricating circuit. Fresh contaminant is introduced in slurry forminto the test reservoir, mixed with the uid in the reservoir, and pumped throughthe test lter, contaminant not captured by lter is returned to the reservoir foranother pass through the lter.

MULTIPLE CARTRIDGESTwo or more cartridges fastened together end to end,to make up one element.

NEGATIVE PRESSUREVacuum or suction.

NOMINALArbitrary term used to describe or dene a degree of ltration. Theltration industry uses various methods of determining nominal ratings which arenot necessarily interchangeable. Generally nominal references 98% removal ofsolids above a specied micron rating on a single pass basis. See absolute.

NOMINAL RATINGAn arbitrary micrometer value indicated by ltermanufacturer. Due to lack of reproducibility, this rating is deprecated.

NONAQUEOUSNot water borne, water related, water resembling, nor

containing water.NONPOLARCompound or element whose electron capacity is satised. Aneutral condition that will remain unreactive. Not polar. See polar.

NONTOXICHaving a non-poisonous effect.NONWOVENA lter cloth or paper that is formed of synthetic bers that arerandomly oriented in the media. Usually held together with a binder.

NORMAL PILINGArrangement structure of lter cake as formed.NOZZLESConnections at the inlet and outlet of a housing through whichproduct ows; or connections in a housing which permit connecting ofaccessories, etc. Term nozzle is not considered as descriptive.

NPTNational pipe thread standard.

N


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NTP ozone

NTPNormal conditions of temperature and pressure. Refers to a gas measuredat a pressure one (1) atmosphere absolute (760 mm of Hg) and a temperature of0C; some sources use a different reference temperature to dene NTP.

OCCLUDEDTaken in and retained, absorbed.ODOutside diameter.ON-STREAMDescribes when a lter system is producing a ltered product.OPEN AREAPore area of lter medium, often expressed as a percentage of thetotal area.

OPERATING PRESSURENormal pressure at which a system operates.

OPERATING PRESSURE, CRITICALPressure above the normal or designlimits which may cause damage or rupture.OPERATING PRESSURE, MAXIMUMMaximum pressure allowed in thesystem.

ORGANICDescribes the vast number of chemical substances containingcarbon, hydrogen and oxygen.

ORGANIC SOLVENTSSubstances in which an organic material will dissolve.ORIFICE PLATEPlate with a central circular orice which is clamped in a pipeor duct. Dependent on the type of plate, pressure tappings are provided as anintegral part of the plate or on each side of it in the duct. The rate ow of uid inthe pipe or duct may be derived from measurement of the pressure differenceacross the plate.

OSMOSISDiffusion of a solvent through a semi-permeable membrane froma dilute solution into a more concentrated solution, thus tending to equalize the

concentration of each side of the membrane.OUT OF BALANCE PRESSUREPressure difference on either side of alter press plate which may be induced by blockage of the feed ports and/orinconsistent physical conditions within adjacent lter chamber.

OUTER SHELLOuter covering of an element, usually perforated or screen.OUTER WRAPOutside covering of an element.

OUTLET (FILTRATE OUTLET)Ports integrally formed in a lter plate throughwhich ltrate can escape from the lter chambers.OUTSIDE-INFlow of product from outside to inside of element.OXIDECombination of oxygen with another element.OXIDATIONChemical combination of any substance in which the oxidationstate (positive valence) of an element is increased.

OZONEBluish gas which becomes indigo blue when compressed; highlyexplosive under pressure and for this reason is not used in industry in thisform but as ozonized air created by electric discharge. Once thought to bebenecial to health, ozone is now considered to be harmful and its appearancein electrostatic precipitators associated with air is therefore undesirable. Efcientbactericide in the treatment of water, in which application it does not give rise toundesirable tastes and odors. Main disadvantage is the high cost in the treatmentof large bulk supplies.

O


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packed bed plastisol

PACKED BEDDiscrete materials such as sand, gravel, anthracite, fabricatedrings or saddles, assembled in a conned space as a ltration medium for liquidsor gases.

PAPERMedium used in many elements. A very general term applied to resinimpregnated cellulose. Many types of paper or cellulose, made to specication,are used as a lter medium.

PARTICLESingle piece of solid material which is small in relation to itsenvironment. Normally characterized by its size and shape.

PARTICLE COUNTPractice of counting particles of solid matter in groupsbased on relative size. Frequently used in engineering a lter to a specic task or

to evaluate the performance of a lter under specic operating conditions. Whenused as data to engineer a lter, proper consideration can be given the type ofmedium to be used, expectant life of the medium, and the true cost of operation.

PARTICLE SIZE DISTRIBUTIONTabulation resulting from a particle count ofsolids grouped by specied micron sizes to determine the condition of either theinuent or efuent stream. Usually expressed in percentage of total solids to thespecic group. Example: 31% in the 6 to 10 micron group. See particle count.

PARTICULATERelating to minute, separate particles.PELLET STRENGTHAbility of a pellet to withstand service conditions withoutbreaking or dusting.

PERFORATEDMaterial in which holes have been punched, such as thematerial used to make the center tube of a cartridge.

PERLITESMaterial similar to volcanic glass with concentric shell structure.

PERMEABILITYAbility of a cake or medium to pass liquids; or the rate ofow of uid under a differential pressure through a material. Air permeabilitymeasurement provides a convenient comparison for various media and indicatesthe construction requirements for specic particle size retention. As a rule ofthumb, lower permeability values indicate ner particle retentivity.

PERMEABLEMaterial that has openings through which liquid will pass inltering. Also referred to as porous or pervious.

PERVIOUSSee permeable.pH RANGEArbitrary scale of numbers from 0 to 14 indicating acidity oralkalinity of a solution. A neutral solution has a pH of 7; below 7 represents acidity,and above 7 represents alkalinity.

PHASEMay be continuous, as the basic product owing through a housing;or discontinuous, as the material to be removed from the basic product. Both aredistinct and separate.

PHENOLIC RESINSSynthetic thermosetting resins obtained by thecondensation of phenol or substituted phenols with aldehydes. Used as a binderin cellulose and glass bers to form lter media.

PIGMENTInorganic or organic, natural and synthetic chemical substancesused to color paints, inks. etc.

PLASTISOLSuspension of a thermosetting plastic which can be molded into

any desired shape. Used as a combination end cap and gasket on element.

P


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plate prelt

PLATEAny at surfaced lter element. Usually found in horizontal plate lters.PLEAT, PINCHEDPleat in a pleated lter element, closed off by excessivedifferential pressure or crowding, thus reducing the effective area of the lterelement.

PLEAT, SPACERSUsed to prevent the collapse of pleats in a pleated papercartridge, under the action of differential pressure. Examples are individualspacers of expanded metal or plastic and continuous spacers of plastics orwoven materials, usually wire-cloth.

PLEATEDPhysical form of cartridge made into a convoluted form to resemblethe folds in an accordion.

PLEATINGIn lters with paper medium or other sheet material, pleating meansthe folding processes which provide a large surface area within a given volumeof lter.

PLUGGINGFiltered out particles lling the openings in a medium to the extentof shutting off the ow of product; loading up of the medium so as to reducecapacity. Also referred to as blinding or blocking.

POLARCompound or element capable of receiving or giving electrons. Seenon-polar.

POLYELECTROLYTESynthetic, water-soluble, linear polymers characterized bythe presence of ionizing g

peco facet glossary filtration terms

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