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CLASS 210,	LIQUID PURIFICATION OR SEPARATION
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SECTION I - CLASS DEFINITION

STATEMENT OF CLASS SUBJECT MATTER

This is the primary class for patents directed to treating water or waste liquid, and when not more specifically provided for, the class for patents directed to treating liquids in general or of any kind and provides (1) process and apparatus for (a) separating a component from (b) purifying or (c) effecting a change in water or waste liquid, such process or apparatus not being more specifically provided for in another class; (2) process of treating liquids in general and treating liquid compositions of either general or diverse utilities; (3) apparatus not provided for in other classes, for performing the foregoing processes and treating liquids of any kind; (4) filter materials or compositions peculiar to the above-mentioned processes; and (5) Processes for purification of liquids containing hazardous or toxic waste to produce a nonhazardous or nontoxic product.

SECTION II - LINES WITH OTHER CLASSES AND WITHIN THIS CLASS

A. GENERAL GUIDELINESS

1. Placement of Patents

a. A claim directed to the production, regeneration, or purification of a particular compound or composition (including) solutions in water is classified with the particular compound or composition. The classes providing for these compounds or compositions are set out in section III, B, 2.

A claim directed to purification or separation of water or of liquids in general with disclosure of several species each differently classifiable is classified in this class (210).

b. In classifying a claim to a combined process in which a liquid (e.g., sewage, etc.) is treated, and a useful by-product, energy or treatment is also recovered or achieved, placement is in Class 210 where the primary purpose is liquid treatment and the by-product, energy or other treatment is incidental. Placement is in the other pertinent class if the liquid treatment is incidental to the other process. If it cannot be determined which is the primary purpose of the combined process, placement is in the appropriate chemical class(es) when a chemical by-product is recovered and in this class (210) in all other instances.

Since the identical combined process may be placed as an original in either of two classes, based on intent of the inventor, a cross-reference copy should be placed in the other class involved.

See section II, A, 2 infra, for exceptions to the general rule here stated.

2.. Specific Exceptions.

a. Class 95, Gas Separation: Processes, will take a process including a liquid separation step in a Class 95 operation (e.g., regenerating a scrubbing liquid in a gas scrubbing operation, etc.).

b. A purely physical separation, e.g., filtering, specifically directed to mineral oil, is classified in this class (210), subclasses 767+.

c. A claim to a process of drying a flowable slurry or mass by physical separation, e.g., centrifuging without a step or means of contacting with a gas, is in this class (210) rather than Class 34. See line note to Class 210 in (3) Note to Class 34 definition.

d. Some classes which provide for compositions which may be used in a Class 210 process may also take a claim to a mere use of such composition. These classes include 424 and 521 and the line notes in section II, C set out the conditions which govern placement of patents in these circumstances.

e. The rehabilitation or regeneration of a filter medium, in situ is classified in this class (210), subclasses 791+, rather than in Class 134, Cleaning and Liquid Contact With Solids.

f. Separating liquids by direct application of electrolysis or electric force to the liquid, alone or combined with a step provided for in subclasses 767-808 of this class, is classified in Class 205, Electrolysis: Processes, Compositions Used Therein, and Methods of Preparing the Compositions, when electrolysis is involved, or in Class 204, Chemistry: Electrical and Wave Energy, when other electrical force as provided for in the Class 204 definition is involved.

B. CLASSES PROVIDING FOR RELATED SUBJECT MATTER.

1. Classes Providing A Specific Unit Operation Treatment Of Liquids.

References to Other Classes, below, contains classes pertaining to the following specific unit operation treatment of liquids.

Analyzing:

Burning;

Chlorinating;

Condensing;

Crystal Forming, Single;

Crystallization;

Degassing;

Disinfecting;

Dispensing;

Distilling;

Drinking Storage;

Electrolysis;

Emulsifying;

Evaporating;

Fluoridating;

Freezing;

Handling;

Heating;

Magnetizing;

Mixing;

Preserving;

Refrigerating;

Separating, Centrifugally;

Softening;

Sprinkling, Spraying, Diffusing;

Sterilizing;

Storage;

Testing;

Transporting;

2. Classes Providing Treatment Of A Specific Liquid.

References to Other Classes, below, contains classes pertaining to the following treatment of a specific liquid.

Beverage;

Black Liquor;

Cleaning Fluid;

Colloids;

Coolant;

Culture Broth;

Detergent;

Drug;

Dye;

Electrolyte;

Emulsion;

Fats;

Fertilizer;

Food;

Fuel;

Ink;

Inorganic;

Lubricants;

Medicine;

Oil;

Paints;

Photographic;

3. Classes Having Liquid Treating Apparatus.

References to Other Classes, below, contains classes having liquid treating apparatus in the following art areas.

Analysis;

Carbureting;

Cooling;

Crystal Forming, Single;

Crystallizer;

Dispensing;

Distilling;

Evaporating;

Gas Contact;

Handling;

Heat Exchange;

Mixing;

Oil Refining;

Packing;

Preserving;

Reaction (Chemical);

Reaction, Physical;

SECTION III - REFERENCES TO OTHER CLASSES

SEE OR SEARCH CLASS:

SECTION IV - GLOSSARY

The meaning to be given various "Art" terms appearing in this class, but which have not been included in the GLOSSARY below, is the same as that generally accepted or in common usage.

ABSORB

See SORB.

ACCELERATOR

Agent which promotes an action, but does not necessarily cause the action. An example is a catalyst as contrasted with a reactant. In subclasses 696+ and 702+ no distinction is made between an agent which promotes or one which causes and a search for a compound used as a flocculant is the same as if the compound reacted to cause precipitation.

ACTIVATED SLUDGE

Common term for an aerobic process of treating sewage with micro-organisms in which part of the settled sludge from the treatment is diverted and introduced into the feed of incoming sewage.

ADDITIVE

An agent added to a liquid being treated to either cause a desired result or to promote a result which would occur more slowly or incompletely without the additive. Catalysts filter aids, chemical agents, seeding agents, buffers are all additives.

ADSORB

See SORB.

AEROBIC

Treating liquids, generally sewage, with micro-organisms in the presence of oxygen generally supplied as air or other source of oxygen but sometimes using residual dissolved oxygen. Best known method is "activated sludge". The micro-organisms convert noxious materials to less noxious stuff, e.g., to water, methane, nitrogen oxides, carbon dioxide.

ALGAECIDE

Any material capable of inhibiting or destroying algal growth.

ANAEROBIC

Treating liquids, generally sewage by micro-organisms which change noxious stuff to innocuous materials, in the absence of oxygen. Some solids are made into water and gases as methane, carbon monoxide, etc. A septic tank is an example of anaerobic digestion of sewage.

ANGSTROM

A unit of length used to measure wavelength of lights and diameters of atoms or molecules.

Designated by A and equal to 10^-8cm.

AQUEOUS

A liquid containing water. Generally water is the major part as in blood, brine, milk, etc., but may comprise a substantial but not major portion as in a water-alcohol mixture of various proportions. Usually trace amounts of water are not considered aqueous.

BACTERICIDE

Any material capable of inhibiting or destroying bacteria.

BRACKISH

Somewhat salty, but substantially less so than sea water.

BRINE

A relatively concentrated salt water solution sometimes from wells or industrial sources and including sea water.

CENTRIFUGE

A process or means in which a liquid is revolved about an axis at such a number of revolutions per unit of time that the apparent weight of constituents increases to a point where the constituents tend to concentrate in strata similar to gravity-induced separation based on relative densities.

CHROMATOGRAPHY

A process in which a liquid is flowed along a linear path comprising a sorbent, with which the liquid competes in affinity for a constituent of the liquid. The constituent is sorbed from the moving liquid by the relatively immobile sorbent and redissolved by a later passing portion of the liquid until an equilibrium of the sorbing-dissolving step is set up causing the constituent to concentrate in a specific volume of the sorbent and to move along the path of the liquid at a slower rate than such liquid.

A comprehensive treatise on chromatography is to be found in Kirk-Othmer Encyclopedia of Chemical Technology 2nd ed. Vol. 5, pp. 413-450.

COALESCE

The merging together of small droplets or particles of a material or constituent dispersed in a liquid to form larger bodies of the material or constituent which may be more easily handled.

COLLOIDAL

A state of very fine division of a material dispersed throughout a liquid almost to the point of a true solution and either impossible or extremely difficult to filter or cause to settle.

CONDUCTIVITY WATER

An extremely pure water characterized by high ohmic resistance due to very low rate of ionization. See POLISHING.

CYCLONE

A device using centrifugal force to separate. The process is called cyclonic; see centrifuge.

DESALINATION

The process of removing inorganic salts, most usually sodium chloride, from water.

DIALYSATE

See DIALYSIS.

DIALYSIS

A process of separating a dissolved constituent from a liquid by transport or migration from the liquid through a membrane into a second liquid. The membrane may be semipermeable or the second liquid may have greater affinity for the constituent but the net effect of the combined membrane-extracting liquid is to selectively remove a constituent from the first liquid. The process is provided for in subclasses 644+. An in-depth explanation is given in Kirk Othmer Encyclopedia of Chemical Technology 2nd ed. Vol. 7, pp. 1-20. Dialysate is the product of a dialysis method and the term is not always used for the same product, including retentate and diffusate.

DIFFUSATE

The material passed through in a diffusing process.

DIFFUSE

The passing of a constituent through a membrane or septum.

DIGEST

Process in which material is acted upon by micro-organisms to cause a chemical change. The composting of sludge is a digestion process.

DISPERSION

A mixture of a liquid with an insoluble material in very fine subdivision almost but not quite a true solution.

EFFLUENT

The liquids flowing out of a process, normally the mainstream, can be either a desired product or discard.

FEED

The liquid to be treated, prior to processing.

FILTER

Method of and apparatus for removing solid particles from a liquid by passing the same through a medium with openings smaller than the particles. Microfiltration is filtration down to coolidal and polymeric molecular size. Ultrafiltration and hyperfiltration are more likely transport or diffusion across a membrane process but are called filtration down to molecular and ionic size. See subclasses 650 and 652.

FILTER ELEMENT

Filter medium combined with supporting structure or having a specified shape.

FILTER MEDIUM

Solid separating material or member for separating a constituent from the prefilt due to openings between material particles or in the member.

FILTRATE

Liquid which has been clarified by passing it through a filter medium.

FILTRATION

The separation of solids from a liquid or a liquid from liquids by a solid separating medium due to openings in the medium or between discrete particles.

FLOC

Flocculated clumps of suspended or dispersed small particles resulting from accretion and used as sites for further accretion of suspended matter. See subclass 715.

FLOCCULATION

A clumping together of finely divided particles of material dispersed in a liquid to a state where filtration or settling of the material is possible. See subclasses 702+.

FLUID

Material that flows, generally gas or liquid but sometimes including mixtures of these with particulate solids such as slurry, sludge, gels, etc. Some materials are thixatropic, i.e., fluid when agitated but jellylike when at rest. Pumpable sludge is considered a liquid for treatment in this class.

FOULING

The act of depositing on the membrane surface something which will impede its proper functioning. Sometimes also termed "blinding".

GEL

A colloidal dispersion of a solid in a liquid with a jellylike texture. Use of a gel in chromatography is in subclass 635, and separating the constituents of a gel are in subclass 702.

GRAVITY, BY

A separation process depending on differences in density to separate freely movable constituents such as cream rising to the top of the milk. Draining or allowing a liquid to drip from solids held by a screen or grid is not gravity separation.

HYDROPHILIC

Water attractive or wettable.

HYDROPHOBIC

Water-repellent or nonwettable.

HYPERFILTRATION

Filtration to the ultimate degree to molecular or ionic size, but most likely membrane transport or diffusion phenomenon. See FILTER and subclass 652.

IMHOFF

A two-story septic tank of special design to allow digestion of sludge in lower chamber with settling in upper chamber and passage of settled sludge from upper to lower chamber. Process is anaerobic and provided for in subclasses 602+.

INERT MATERIAL

Stuff that does not cause or promote any change in liquid or component being treated. May act as filler, support, or carrier for active material. See subclass 679.

LIQUID

A flowable material comprising at least one component that is a true liquid under the conditions of treatment. A slurry, wet sludge, pumpable sediment, emulsion, froth, all are considered liquid for treatment in this class.

MAINSTREAM

The main body of liquid being treated as constrasted with separated constituents. The mainstream may comprise several divided streams, some of which undergo treatment and which are a substantial part of the overall feed but a relatively small stream diverted for a dosing technique in which agents are added in a concentrated amount and the diverted stream is diluted with the main body is not considered to be the mainstream, per se. A recirculated portion of the stream is not considered to be the mainstream.

MEMBRANE

A skinlike thin film which acts as a barrier or container wall; the usual form of a permeable or semipermeable septum. A semipermeable membrane is a skinlike, relatively thin film which serves to define a barrier or container wall to at least one of the constituents of a solution or colloidal suspension and allows at least one other constituent to pass through by a mechanism which may include but goes beyond mere straining and which mechanism is in part due to differences in behavior of the constituents of the solution or suspension with respect to the material of the membrane. The constituents vary in their ability to diffuse through or to wet the membrane.

Membranelike includes mambrane, per se, and material which, while not strictly in a self-supporting skinlike structure, functions in an analogous manner and includes a layer of fine particulate matter or an emulsion as set out in subclass 643.

A process which depends only on the relative size of pores and molecules or ions of a constituent is a filtering or straining process and is classified under separation, subclass 767.

MICRON

A linear measurement equal to one millionth of a meter, one thousandth of a mm, 39 millionths of an inch.

MICRO-ORGANISM

Living plants or animals of a size normally visible only through a microscope and includes bacteria, yeast, fungi, and virus. For purposes of this class, algae are not considered micro-organisms. The scope of this term is coextensive with the organisms of Class 435, Molecular Biology and Microbiology.

MICROFILTER

See FILTER.

MOLECULAR SIEVE

A sorbent with an extremely large volume of pores, each of about molecular size, capable of selectively sorbing gases and other material in molecular form; generally of Zeolite.

OIL

Organic material of slick or slippery feel including long chain hydrocarbons esters of higher fatty acid and derived from petroleum, fats, greases, and oils of animal or vegetable origin.

OLEOPHILIC

Oil attractive or wettable by oil.

OLEOPHOBIC

Oil repelling.

OSMOSIS

Phenomenon in which solvent migrates or is transported across a barrier from a less concentrated solution to a more concentrated solution separated by the barrier tending to equalize the concentrations. The force driving the solvent is dependent on the materials of the liquids and the barrier or septum, and a counter force of greater magnitude will effect reverse migration or reverse osmosis causing solvent to migrate from the more concentrated to the less concentrated solution. A comprehensive treatise on osmosis and reverse osmosis is given in Kirk-Othmer Encyclopedia of Chemical Technology 2nd ed. Vol. 14, pp. 345-355.

OXIDANT

An agent which extracts electrons from a chemical moiety and increases its positive or decreases its negative valence. Often an oxygen or halogen containing material.

PERMEABLE

Property of allowing passage or migration of other material through a barrier or septum of the material so designated. The migration phenomenon is due primarily to the chemical nature of the materials involved and may include molecular weight or size as a factor.

PERMEATE

Material which has passed through a permeable or semipermeable membrane.

pH

The measure of the acidity or basicity (alkalinity) of a liquid. Also determines the sweetness or sourness of a liquid. The original value was the log of the reciprocal of the hydrogen ion concentration.

POLISHING

An ion exchange process in which the ions released to the liquid are only H⁺ and OH^-. A method of achieving very pure water. See CONDUCTIVITY WATER.

PREFILT

Material to be filtered, also known as feed, influent, intake.

RESIDUE

Material retained by membrane, septum, filter, settling tank, etc.

RETENTATE

Material held back by membrane or filter, not allowed to migrate or pass through.

REVERSE OSMOSIS

See OSMOSIS.

SEMIPERMEABLE

Permeable to only some of materials which may be in intimate association as in a solution. Usually applied to membrane, see MEMBRANE.

SLUDGE

Concentrate of settled colloidal suspension with a mushy or mud texture, a gel with up to more than 90 percent usually water) but quite viscous. It may contain indiscriminate solids as grits, fiber, wood chip, and emulsions. While still wet, treatment is proper for this class, but the same material when completely dry may be referred to as sludge. See ACTIVATED SLUDGE.

SORB, SORBING

The attracting by a solid material of a liquid wherein the liquid permeates the body of the solid, either in pores or throughout the material itself or of a finely divided constituent, suspended or dissolved in a liquid, on the surface of or in pores of the material. Examples of the former are methods using sponges, mops, and pads and of the latter are methods using activated charcoal clays and zeolites. In this class, no distinction is made between absorption and adsorption. Processes using sorption for separation are provided for in subclasses 660+. (See Kirk-Othmer Encyclopedia of Chemical Technology 2nd ed. Vol. 1, pp. 44-75 and 421-469.)

SUSPENSION

Liquid carrying throughout its volume in extremely fine subdivision an insoluble substance (solid or another liquid) which will not settle under gravity nor can be filtered without special treatment such as addition of chemical agents. A DISPERSION. See FLOCCULATION, GEL, and MEMBRANE.

SYNTHETIC

A material not found in nature, but man-made from chemical building blocks, with properties resembling naturally occurring materials. It does not include man-made duplicates of natural material or chemical modified natural materials. For example, regenerated cellulose and cellulose acetate are not included nor is zein, but polyester, vinyl, and nylon are included.

TRICKLING FILTER

A particulate bed of designed coarseness through which liquid is gravity fed at a rate to maintain relatively thin films on the particles and enhance air liquid contact to promote aerobic treatment of the liquid. An alternate method may be programmed flooding and draining of the bed. The treatment using such a bed is in subclasses 616+.

ULTRAFILTRATION

Filtration of a solution or colloid, retaining a constituent of macromolecule dimension. See FILTRATION and MEMBRANE.

VAPOR

A normally liquid material in a gaseous state, e.g., steam. Separating or purifying a fluid in the gaseous state is proper for Class 55, Gas Separation, but treating a liquid with gaseous constituents is provided for in subclasses 603+, 640, 664, 707, 718, and 750.

WASTE

A liquid that is to be discarded. The term includes effluent from domestic or industrial sources, e.g, sewage wash water spent processing fluids, etc., and refers to liquid to be treated and liquid which has been treated to allow discharge to the environment.

SUBCLASSES

85	WITH ALARM, INDICATOR, REGISTER, RECORDER, SIGNAL OR INSPECTION MEANS:
	This subclass is indented under the class definition.  Apparatus with an alarm indicator, register, recorder or signal, showing a condition of the subject matter of the class; or with means which permit inspection of normally hidden parts of the apparatus or of the fluid inside the apparatus. SEE OR SEARCH THIS CLASS, SUBCLASS: 138+, for controlled devices including only the driving mechanism of a clock without any indication other than that of a conventional clock. SEE OR SEARCH CLASS: 73,  Measuring and Testing,   appropriate subclasses, for pressure, level, temperature, etc., measuring and indicating means, per se, especially subclass 61.41 for methods and means for testing which determines a characteristic of a separated constituent. 116,  Signals and Indicators,   appropriate subclasses, for mechanical signals and indicators, per se. 118,  Coating Apparatus,   subclasses 712+ for coating apparatus and a signal or an indicator. 222,  Dispensing,   subclasses 23+ for dispensers with recorder, register, indicator, signal or exhibitor. 235,  Registers,   appropriate subclasses, for registers, per se. 340,  Communications: Electrical,   subclasses 603+ for electrical automatic fluent material responsive indicating systems. 346,  Recorders,   appropriate subclasses, for recorders, per se.

86	Material level or thickness responsive:
	This subclass is indented under subclass 85.  Apparatus responsive to a change in the level or thickness of a material being treated within the apparatus.

87	Responsive to fluid flow:
	This subclass is indented under subclass 85.  Apparatus responsive to flow of fluids.

88	Meter-controlled cyclic systems:
	This subclass is indented under subclass 87.  Apparatus in which a meter controls an operating cycle of the apparatus.

89	With time control:
	This subclass is indented under subclass 88.  Apparatus including means operating during or after a predetermined interval of time.

90	Fluid pressure responsive:
	This subclass is indented under subclass 85.  Apparatus responsive to fluid pressure.

91	Position or extent of motion:
	This subclass is indented under subclass 85.  Apparatus comprising means which gives information as to the position of a movable or adjustable part of the apparatus.

92	Test valve:
	This subclass is indented under subclass 85.  Apparatus including a valve which may be opened for test purposes.

93	In effluent conduit:
	This subclass is indented under subclass 85.  Apparatus comprising a section in a conduit downstream from treating means.

94	Transparent:
	This subclass is indented under subclass 85.  Apparatus in which the inspection means is a transparent part of a treating means. SEE OR SEARCH CLASS: 222,  Dispensing,   subclasses 154+ for dispensers with inspection devices.

95	Sight glass:
	This subclass is indented under subclass 94.  Apparatus comprising transparent means associated with treatment apparatus through which material being treated can be viewed. SEE OR SEARCH CLASS: 73,  Measuring and Testing,   subclasses 323+ for liquid level sight glasses of general application.

96.1	CONSTITUENT MIXTURE VARIATION RESPONSIVE:
	This subclass is indented under the class definition.  Apparatus in which an operating condition of the apparatus is controlled by variations of a constituent quality of a liquid mixture as determined by physical or chemical tests of the liquid mixture. SEE OR SEARCH THIS CLASS, SUBCLASS: 662, for composition testing in ion exchange or sorption processes. SEE OR SEARCH CLASS: 23,  Chemistry: Physical Processes,   subclass 230 for analytical and analytical control methods there provided for. 137,  Fluid Handling,   subclasses 3+ for processes of mixing plural fluids of diverse characteristics; and subclasses 88+ for a system involving mixture condition maintaining or sensing.

96.2	With membrane:
	This subclass is indented under subclass 96.1.  Apparatus having a filtering means composed of a thin, enveloping or lining substance, i.e., membrane. SEE OR SEARCH THIS CLASS, SUBCLASS: 257.1, for a membrane within a storage unit in serially connected distinct treating apparatus. 348+, for apparatus which uses a semipermeable septum which does not provide for continuous streams on both sides of the septum. 433+, for similar apparatus which uses in ordinary filter septum. 500.1, for membrane, per se. 541, for membrane supports, frames, and spaces. 634+, for process of using a septum selective as to composition. SEE OR SEARCH CLASS: 127,  Sugar, Starch, and Carbohydrates,   subclass 10 for a sugar solution dialyzer. 204,  Chemistry: Electrical and Wave Energy,   subclasses 252+ for a similar device using an electric current. 604,  Surgery,   subclass 6.09 for membrane separation devices used in blood treat

97	FLOW, FLUID PRESSURE OR MATERIAL LEVEL, RESPONSIVE:
	This subclass is indented under the class definition.  Apparatus having means responsive to variations in flow, material level or fluid pressure to control means to effect an operation or change in an operating condition. SEE OR SEARCH THIS CLASS, SUBCLASS: 156+, for a fluid stream or residue operated flume stream type separator. 349, for a filter with pulsation dampening means. 354, for a filter medium or cleaner or agitator moved by fluid. SEE OR SEARCH CLASS: 162,  Paper Making and Fiber Liberation,   subclass 258 for paper making apparatus having automatic control of stock consistency, and subclass 259 for automatic control of stock feed to the foraminous forming screen. 204,  Chemistry: Electrical and Wave Energy,   subclass 662 for an electrical or magnetic apparatus to separate or purify a liquid with a control means responsive to a sensed liquid level.

98	Fluid current controlled cyclic system:
	This subclass is indented under subclass 97.  Apparatus in which an operating cycle is controlled in response to the liquid flow. SEE OR SEARCH THIS CLASS, SUBCLASS: 88+, for a meter controlled cyclic system.

99	Prefilt deverting to drain by prefilt accumulation:
	This subclass is indented under subclass 97.  Apparatus in which there is means for diverting the initial charge of prefilt to drain, said means being responsive to accumulation of prefilt in a nonseparating receiver. SEE OR SEARCH THIS CLASS, SUBCLASS: 130+, for a fluid pressure responsive bypass. 421, for a filter with a manually operated prefilt deflector. SEE OR SEARCH CLASS: 137,  Fluid Handling,   subclass 120 for self-controlled branched flow systems having alternate outflows including liquid level sensing means.

100	Flow cut-off requiring reset:
	This subclass is indented under subclass 97.  Apparatus which causes a flow controller to close, after which a necessary resetting operation must be preformed by an external operator.

101	Proportionate feed means:
	This subclass is indented under subclass 97.  Apparatus including means to maintain the ratio between plural flows at a predetermined value in response to means sensing a change in fluid condition in at least one of the flow lines. SEE OR SEARCH THIS CLASS, SUBCLASS: 105, for diverse condition responsive controls one of which controls an auxiliary liquid inlet. 127, for a separator having a float controlled auxiliary fluid inlet. 198+, for separatory means having means to add treating material. SEE OR SEARCH CLASS: 137,  Fluid Handling,   subclass 9 for self-proportioning fluid handling processes and subclasses 98+ for self-proportioning apparatus. 222,  Dispensing,   subclass 57 for dispensing devices which are automatically controlled by the weight, volume or pressure of a second dispensed material, and subclass 130 for plural sources at least one of which is nondispensing.

102	Programming plural units:
	This subclass is indented under subclass 97.  Apparatus governing the order in which individual separatory units of a plurality of such units are used.

103	Diverse sensing means:
	This subclass is indented under subclass 97.  Apparatus which includes plural sensing means differing characteristics other than mere size.

104	Responsive to material level:
	This subclass is indented under subclass 103.  Apparatus responsive to a change in the level of the liquid or solids.

105	With control for auxiliary liquid inlet:
	This subclass is indented under subclass 103.  Apparatus including the control of introduction of an auxiliary liquid to a treatment chamber. SEE OR SEARCH THIS CLASS, SUBCLASS: 101, for separatory apparatus combined with means to feed treating material thereto proportionately to the material being treated.

106	Filter cleaning:
	This subclass is indented under subclass 97.  Apparatus relating to means to rehabilitate or clean a filter medium. SEE OR SEARCH THIS CLASS, SUBCLASS: 407+, for filter means combined with cleaning means.

107	Rotary movement of filter or mechanical cleaner:
	This subclass is indented under subclass 106.  Apparatus wherein the filter medium or the rehabilitating means is rotated. SEE OR SEARCH THIS CLASS, SUBCLASS: 359+, for a movable filter medium.

108	Backwash or blowback:
	This subclass is indented under subclass 106.  Apparatus comprising backwash or blowback means. SEE OR SEARCH THIS CLASS, SUBCLASS: 420+, for a filter provided with a flow controller providing selective direction flow therethrough.

109	Discharge of treated material:
	This subclass is indented under subclass 97.  Apparatus which controls a treated material discharge outlet. SEE OR SEARCH CLASS: 137,  Fluid Handling,   subclasses 395+ for liquid level responsive outlet controls for tanks of general utility, and subclasses 577+ for fluid handling tanks of general utility having adjustable outlets, especially subclass 578 for float supported outlets.

110	With separator inlet control:
	This subclass is indented under subclass 109.  Apparatus with means controlling an inlet to a separator. SEE OR SEARCH THIS CLASS, SUBCLASS: 103+, for control by diverse sensing means.

111	Responsive to prefilt accumulation or filter clogging:
	This subclass is indented under subclass 109.  Apparatus responsive to liquid to be treated or to an increase in pressure upstream of a filter. SEE OR SEARCH THIS CLASS, SUBCLASS: 99, for means diverting prefilt to drain responsive to prefilt accumulation. 130+, for bypass means responsive to pressure.

112	Heavier constituent:
	This subclass is indented under subclass 109.  Apparatus in which the material is a heavier constituent.

113	By weight of solids:
	This subclass is indented under subclass 112.  Apparatus responsive to weight of accumulated solids.

114	By treated liquid accumulation:
	This subclass is indented under subclass 112.  Apparatus responsive to treated liquid accumulation.

115	With lighter constituent outlet control:
	This subclass is indented under subclass 112.  Apparatus controlling a lighter constituent discharge outlet. SEE OR SEARCH THIS CLASS, SUBCLASS: 103+, for apparatus including diverse sensing means.

116	Permitted by filtrate accumulation:
	This subclass is indented under subclass 109.  Apparatus wherein the discharge outlet is normally closed and permits discharge of filtrate responsive to filtrate accumulation. SEE OR SEARCH THIS CLASS, SUBCLASS: 114, for means controlling discharge of a heavier constituent responsive to treated liquid accumulation. 117+, for valve means responsive to change in direction of the flow to prevent backflow.

117	Check valve controlled:
	This subclass is indented under subclass 109.  Apparatus including flow control means allowing flow in only one direction. SEE OR SEARCH THIS CLASS, SUBCLASS: 137, for means maintaining stream pressure or flow in separatory apparatus.

118	Non-closing, e.g., sand valve:
	This subclass is indented under subclass 117.  Apparatus comprising a variable restrictor responsive to flow direction whereby flow increases during backwash.

119	Float type:
	This subclass is indented under subclass 117.  Apparatus comprising a float operated valve means. SEE OR SEARCH CLASS: 137,  Fluid Handling,   subclasses 247.15+ for line condition change responsive flow controllers combined with liquid seal traps, subclasses 409+ for float operated valves, and subclasses 455+ for line condition responsive valves, especially subclasses 511+ for check valves.

120	Vent control:
	This subclass is indented under subclass 97.  Apparatus comprising means controlling an opening above a liquid level for entrance or exit of a gas. SEE OR SEARCH THIS CLASS, SUBCLASS: 130+, for a liquid bypass which may also serve as a vent. 472, for a filter means with vent means.

121	Float:
	This subclass is indented under subclass 97.  Apparatus in which the responsive means is a float. SEE OR SEARCH THIS CLASS, SUBCLASS: 104, for diverse sensing means responsive to material level.

122	Controls movable separator:
	This subclass is indented under subclass 121.  Apparatus which controls the movement of a separatory medium.

123	Controls valve:
	This subclass is indented under subclass 121.  Apparatus in which the float controls valve means.

124	Controls flow between two separators:
	This subclass is indented under subclass 123.  Apparatus in which the valve means is located in the flow stream between two separators.

125	Separator between float and valve:
	This subclass is indented under subclass 123.  Apparatus in which the float and the valve means are on opposite sides of a separatory means.

126	Float in separate rehabilitating fluid tank:
	This subclass is indented under subclass 123.  Apparatus in which the float is located in a separate tank or compartment provided for the storage of rehabilitating fluid.

127	Additional fluid inlet control:
	This subclass is indented under subclass 123.  Apparatus in which the valve means controls admission of a fluid other than liquid being treated. SEE OR SEARCH THIS CLASS, SUBCLASS: 101+, for a separator with proportionate feed means for adding treating material. 198+, for a separator with means to add treating material.

128	Float in receptacle other than that of separator:
	This subclass is indented under subclass 123.  Apparatus in which the float is in a nontreating chamber. SEE OR SEARCH THIS CLASS, SUBCLASS: 126, for a float in separate rehabilitating fluid tank.

129	In flow between inlet and separator:
	This subclass is indented under subclass 128.  Apparatus in which the float is in the flow between a controlled inlet and a separator.

130	Fluid pressure responsive by-pass:
	This subclass is indented under subclass 97.  Apparatus comprising means responsive to pressure to bypass liquids around treatment means. SEE OR SEARCH THIS CLASS, SUBCLASS: 99, for means to divert on initial charge of prefilt to drain. 790, for separating processes involving dividing and recombining the flow.

131	By movement of separation medium:
	This subclass is indented under subclass 130.  Apparatus in which the responsive means is a separating element or filter medium which provides a bypass by flexing or compression thereof or by movement in its entirety. SEE OR SEARCH THIS CLASS, SUBCLASS: 356, for fluid operated means to flex a filter means during operation. 398+, for movable elements within a casing, the movement of which may open a bypass. 738, and 748, for processes including pulsation or oscillation essential to the separation or purification.

132	With additional separation or treating means:
	This subclass is indented under subclass 130.  Apparatus in which the by-pass contains separation or treatment means. SEE OR SEARCH THIS CLASS, SUBCLASS: 294+, for diverse distinct separators. 806, for processes including plural separatory steps.

133	In inlet and outlet closure header:
	This subclass is indented under subclass 130.  Apparatus in which a separator casing is closed by a unitary attached header which header includes at least an inlet and an outlet and the pressure response bypass means therebetween.

134	Plural elements controlled:
	This subclass is indented under subclass 97.  Apparatus including plural variable flow affecting elements, at least one of which is controlled by the sensing means. SEE OR SEARCH THIS CLASS, SUBCLASS: 103+, for apparatus including diverse sensing means controlling an operating phase or phases in a separator. 110, for line condition responsive means controlling discharge of treated material and the inlet to a separator. 115, for line condition responsive means controlling discharge of a heavier constituent and discharge of a lighter constituent.

135	Including manually controlled element:
	This subclass is indented under subclass 134.  Apparatus including at least one manually operated flow controller.

136	Check valve:
	This subclass is indented under subclass 97.  Apparatus having means responsive to a change in a flow line condition acting of the face of a valve disc or plug itself to permit flow in one direction only. SEE OR SEARCH THIS CLASS, SUBCLASS: 103, for diverse sensing means. 117+, for a check valve controlling discharge of treated material. 120, for a check valve controlled vent. 130+, for a fluid pressure responsive bypass. 416, for valves which form a part of a pump organization.

137	Maintaining stream pressure or flow:
	This subclass is indented under subclass 97.  Apparatus to regulate pressure of or rate of flow of a liquid. SEE OR SEARCH THIS CLASS, SUBCLASS: 111, for means discharging treated material responsive to filter clogging. 114, for means discharging the heavier constituent responsive to treated liquid accumulation. 116, for discharge of treated material responsive to filtrate accumulation. 130, for a fluid pressure responsive bypass.

138	WITH TIME CONTROL:
	This subclass is indented under the class definition.  Apparatus in which the time at which an element of an treating means is actuated, or the length of time taken to perform an operation thereof is controlled. SEE OR SEARCH CLASS: 68,  Textiles: Fluid Treating Apparatus,   subclasses 12 and 23+ for treating machines having centrifugal extractor features and time-controlled means associated therewith.

139	Of additional fluid:
	This subclass is indented under subclass 138.  Apparatus which introduces to the treating means a fluid in addition to that being treated.

140	Preparation for treating operation:
	This subclass is indented under subclass 139.  Apparatus in which the additional fluid serves to prepare the treating means for a treating operation.

141	WITH PROGRAM ACTUATOR:
	This subclass is indented under the class definition.  Apparatus in which an actuating means provides either a continuously repetitive operation of a treating device or a single operation terminating in a position to restart an additional cycle, which cycle is more complex than a mere starting or stopping of a single treating device.

142	Plural treating units or sections sequentially controlled:
	This subclass is indented under subclass 141.  Apparatus in which there is a plurality of treating units or sections which are controlled in sequence.

143	AUTOMATIC CONTROL:
	This subclass is indented under the class definition.  Apparatus having means to sense some condition of a treatment operation and operate a control device. SEE OR SEARCH THIS CLASS, SUBCLASS: 86, for a material level responsive indicator. 87, for a fluid flow responsive indicator. 90, for a fluid pressure responsive indicator. 96.1+, for control responsive to constituent mixture variation. 97+, for control by fluid flow, fluid pressure or material level responsive means. SEE OR SEARCH CLASS: 137,  Fluid Handling,   subclasses 87.01+ for self proportioning or correlated fluid handling systems of general utility.

144	Responsive to vibration or unbalance:
	This subclass is indented under subclass 143.  Apparatus responsive to vibration or unbalance of a movable part of treating means. SEE OR SEARCH THIS CLASS, SUBCLASS: 363+, for a centrifugal extractor with rotation stabilizer. SEE OR SEARCH CLASS: 74,  Machine Element or Mechanism,   subclasses 572+ for flywheels and rotors with balancing or vibration dampening means defining no specific feature of separator construction. 192,  Clutches and Power-Stop Control,   subclasses 116+ for power-stop control of more general utility. 318,  Electricity: Motive Power Systems,   subclasses 445+ for a motor control systems, particularly subclass 460 for vibration responsive control.

145	Responsive to rotation:
	This subclass is indented under subclass 143.  Apparatus responsive to a condition of rotation of a part of the treating means. SEE OR SEARCH THIS CLASS, SUBCLASS: 144, for vibration or unbalance responsive control. SEE OR SEARCH CLASS: 192,  Clutches and Power-Stop Control,   subclasses 103+ for a speed responsive clutch for a centrifugal extractor.

146	Controlled cover latch:
	This subclass is indented under subclass 145.  Apparatus in which there is a treatment casing provided with a closure and a latch controlled by the rotation responsive means. SEE OR SEARCH CLASS: 192,  Clutches and Power-Stop Control,   subclass 136 for an automatic cover latch control for a centrifugal extractor.

147	Controlled discharge means:
	This subclass is indented under subclass 145.  Apparatus which controls a discharge means for a constituent of the class subject matter. SEE OR SEARCH THIS CLASS, SUBCLASS: 109+, for control of discharge responsive to fluid flow, pressure or material level.

148	Container movement operated:
	This subclass is indented under subclass 143.  Apparatus operated accidentally or unintentionally by movement of a container used in a treating operation. SEE OR SEARCH THIS CLASS, SUBCLASS: 235, for actuation of a flow controller on assembly of parts. SEE OR SEARCH CLASS: 137,  Fluid Handling,   subclass 43 for a vent valve opened or closed by the tipping of a container.

149	Thermal:
	This subclass is indented under subclass 143.  Apparatus having means responsive to a thermal condition.

150	WITH GAS-LIQUID SURFACE CONTACT MEANS:
	This subclass is indented under the class definition.  Apparatus consisting of solid contact means to increase the surface area of a liquid in a gas-liquid contact device whereby the contact is enhanced. SEE OR SEARCH CLASS: 261,  Gas and Liquid Contact Apparatus,   appropriate subclasses for gas and liquid contact apparatus there provided for.

151	With separator:
	This subclass is indented under subclass 150.  Apparatus combined with a separator.

153	STRUCTURAL INSTALLATION:
	This subclass is indented under the class definition.  Apparatus combined with (1) means performing an operation external to the subject matter of this class, (2) combined with a static construction installation, (3) specifically related to a particular geographic feature wherein there is included only enough structure foreign to this class (210) to associate it with the apparatus. SEE OR SEARCH THIS CLASS, SUBCLASS: 241+, for a separator combined with a movable support. 244+, for a draining type separator comprising a portable receptacle with a hood or closure. 419, for a filter attached to or within a portable prefilt receiver having a flow controller for the material being treated. 464+, a portable receptacle draining type filter. 473+, for a filter resting on a supporting receiver. SEE OR SEARCH CLASS: 4,  Baths, Closets, Sinks, and Spittoons,   appropriate subclasses particularly subclass 652 for strainers combined with sink structure and subclasses 286+ for strainers and stoppers peculiar to that art. 37,  Excavating,   subclasses 318+ for a dredger combined with a screen separator. 68,  Textiles: Fluid Treating Apparatus,   subclasses 19+ for a laundry machine combined with a fluid extractor, and subclasses 235+ for a separator combined with a washing machine drain. 99,  Foods and Beverages: Apparatus,   subclass 408 for a deep fat fryer type cooker having crumb or sediment segregation means. 122,  Liquid Heaters and Vaporizers,   subclass 431 for a filter in a boiler. 137,  Fluid Handling,   subclass 140 for a siphon combined with a separatory means, and subclasses 343+ for a structural installation of a fluid handling apparatus. 159,  Concentrating Evaporators,   subclass 42 for a concentrating evaporator combined with a strainer or skimmer. 222,  Dispensing,   subclasses 189.06+ for a dispenser with a strainer, and subclass 565 for a sifting dispenser. 435,  Chemistry: Molecular Biology and Microbiology,   subclasses 289.1+ for fermentation apparatus including separating means, particularly subclass 295.3 for a bioreactor with the combination of a draft tube and a semipermeable membrane or filter, subclasses 297.1+ for a bioreactor including a semipermeable membrane or filter, and subclass 308.1 for an apparatus for separating a microorganism from culture media.

154	Flume stream type:
	This subclass is indented under subclass 153.  Apparatus comprising separating means placed in or at the entrance of an open channel confining a flowing stream to prevent solids, such as debris or fish, from passing downstream. SEE OR SEARCH THIS CLASS, SUBCLASS: 131, for a movable animal stop in a sewer comprising a fluid pressure responsive bypass. 173+, for flume stream type separators with comminuting means. SEE OR SEARCH CLASS: 405,  Hydraulic and Earth Engineering,   subclasses 118+ for specific open channel construction or flow control features other than that forming the inlet and outlet to a separator.

155	Plural or diverse screens:
	This subclass is indented under subclass 154.  Apparatus including plural, spaced, straining elements or straining elements of different shapes or kinds. SEE OR SEARCH THIS CLASS, SUBCLASS: 294+, for diverse distinct separators of general utility. 322+, for plural distinct separators of general utility.

156	Fluid stream or residue operated:
	This subclass is indented under subclass 154.  Apparatus moved by the flowing stream or by a collection of residue on the separator medium. SEE OR SEARCH THIS CLASS, SUBCLASS: 354+, for filter structure similarly operated.

157	Revolving cylindrical strainer:
	This subclass is indented under subclass 156.  Apparatus in which the separating medium is a cylindrical filter rotating about a central axis.

158	With cleaner for movable strainer:
	This subclass is indented under subclass 154.  Apparatus including means for cleaning the filter which is movable.

159	With cleaner and means to remove residue therefrom:
	This subclass is indented under subclass 154.  Apparatus including a filter cleaner which is a movable solid means, as a brush, with means to remove residue therefrom.

160	Endless belt strainer:
	This subclass is indented under subclass 154.  Apparatus in which the separating means is a movable endless foraminous belt.

161	Revolving strainer:
	This subclass is indented under subclass 154.  Apparatus in which the separating means is a strainer mounted to revolve in the fluid stream.

162	Fixed strainer:
	This subclass is indented under subclass 154.  Apparatus in which the separating means is a strainer stationarily mounted in the fluid stream.

163	Grated inlet surface drain:
	This subclass is indented under subclass 153.  Structures including a strainer in outlet means which provide drain means for a surface, as a floor. SEE OR SEARCH THIS CLASS, SUBCLASS: 116, for a grated surface inlet drain including means responsive to filtrate accumulation permitting discharge of treated material. 119, for a grated surface drains having back-flow preventing means. 247, for a strainer with a filtrate deflector. 459, for a pipe or plate attached filter. SEE OR SEARCH CLASS: 4,  Baths, Closets, Sinks, and Spittoons,   appropriate subclasses, particularly subclasses 268+ , 275+, 286+, 596+, 640+, and 650+ for plumbing apparatus including drains with grated inlets. 52,  Static Structures (e.g., Buildings),   subclass 12 for cover with an eave or valley gutter with a separator. 285,  Pipe Joints or Couplings,   subclass 42 for flashed pipe-to-plate joint. 404,  Road Structure, Process, or Apparatus,   subclasses 2+ for roadway drain or gutter structure.

164	Flat grating at surface level:
	This subclass is indented under subclass 163.  Structures where the upper face of the strainer is flat and is level with its associated surface.

165	With subsurface weep means:
	This subclass is indented under subclass 164.  Structures which include means to dispose of subsurface see page e.g., weep holes. SEE OR SEARCH CLASS: 285,  Pipe Joints or Couplings,   subclass 14 for a pipe joint including leakage or drip disposal means comprising a weep hole.

166	Concentric guard ring or rib:
	This subclass is indented under subclass 163.  Apparatus comprising a concentric ring or rib between the strainer and its associated surface wherein the ring or rib projects above the plane of the surface.

167.01	Closed circulating system:
	This subclass is indented under subclass 153.  Apparatus comprising a group of devices, including liquid purification or separation means, through which the liquid being purified or separated is continuously returned and reused. SEE OR SEARCH THIS CLASS, SUBCLASS: 194+, for liquid purification or separation apparatus including recirculation means. SEE OR SEARCH CLASS: 68,  Textiles: Fluid Treating Apparatus,   subclass 18 for textile fluid treating apparatus including recirculation means and liquid purification or separation means for the used solvent. 118,  Coating Apparatus,   subclasses 600+ for coating apparatus with means for treatment of the coating material involving recirculation and liquid purification or separation. 123,  Internal-Combustion Engines,   subclass 41.55 for internal- combustion engine cooling system combined with liquid purification or separation means and subclass 196 for internal- combustion engine lubricator means combined with liquid purification or separation means. 134,  Cleaning and Liquid Contact With Solids,   subclasses 10+ and 109+ for cleaning and liquid contact with solids processes and apparatus including means for purifying or separating the cleaning or contact liquid.

167.02	For lubrication system:
	This subclass is indented under subclass 167.01.  Apparatus in which the liquid purification or separation means is adapted for use in a closed circulating system that provides lubricant to moving parts of a machine. SEE OR SEARCH THIS CLASS, SUBCLASS: 416.5, for a filter, with a pump, gas pressure, or suction source, adapted for use in a lubricating or oil treating system. SEE OR SEARCH CLASS: 123,  Internal-Combustion Engines,   subclass 196 for internal- combustion engine lubricator means combined with liquid purification or separation means. 184,  Lubrication,   subclass 1.5 for automobile crank and gear case service apparatus including liquid purification of separation means and subclasses 6.24+ for lubrication systems combined with liquid purification or separation means.

167.03	Having magnetic treating means:
	This subclass is indented under subclass 167.02.  Apparatus having means that attract iron and certain other materials because of a surrounding field of force produced by motion of its atomic electrons and alignment of its atoms. (1) Note. The magnetic treating means generally is used to cause separation of iron-containing material from the lubricant. However, the magnetic treating means may subject the lubricant to a process that otherwise improves or alters the lubricant (e.g., mixing, etc.). SEE OR SEARCH THIS CLASS, SUBCLASS: 167.29, for liquid purification or separation apparatus comprising a closed circulating system having magnetic treating means not for a lubrication system. 222+, for liquid purification or separation apparatus including magnetic treating means not in a closed circulating system.

167.04	Plural separators:
	This subclass is indented under subclass 167.02.  Apparatus that has two or more means for liquid purification or separation.

167.05	Having bypass line:
	This subclass is indented under subclass 167.04.  Apparatus that has means to conduct the lubricant around a device in the closed circulating system.

167.06	With heating or cooling means:
	This subclass is indented under subclass 167.02.  Apparatus that has means to raise or lower the temperature of the lubricant. SEE OR SEARCH THIS CLASS, SUBCLASS: 167.32, for liquid purification or separation apparatus comprising a closed circulating system with heating or cooling means not for a lubrication system. 175+, for liquid purification or separation apparatus with a heater or a heat exchanger not in a closed circulating system.

167.07	Evaporator:
	This subclass is indented under subclass 167.06.  Apparatus in which the means to raise the temperature of the lubricant vaporizes a component to be separated.

167.08	Separator for transmission system:
	This subclass is indented under subclass 167.02.  Apparatus in which the liquid purification or separation means is adapted for use in a closed circulating system that comprises an assembly of parts by which power is transmitted from an engine to a drive axle. SEE OR SEARCH CLASS: 180,  Motor Vehicles,   subclasses 337+ for motor vehicle transmission mechanisms.

167.09	With separator cleaning means:
	This subclass is indented under subclass 167.02.  Apparatus in which means are provided to remove the separated component from the liquid purification or separation means.

167.1	For swimming pool or spa (e.g., skimmer, etc.):
	This subclass is indented under subclass 167.01.  Apparatus in which the liquid purification or separation means is adapted for use with a tank, made of concrete, plastic, or other materials, for holding water that is open at the top for a user to enter, for swimming, relaxation, or recreation (e.g., swimming pool, spa, hot tub, etc.). SEE OR SEARCH THIS CLASS, SUBCLASS: 416.2, for a filter, with a pump, gas pressure, or suction source, adapted for use with a swimming pool. 470, for a filter with a handle. SEE OR SEARCH CLASS: 4,  Baths, Closets, Sinks, and Spittoons,   subclasses 488+ for pools for swimming, relaxation, or recreation.

167.11	With means to add treating material:
	This subclass is indented under subclass 167.1.  Apparatus in which the liquid purification or separation means is combined with means to supply a substance to the water being purified or separated that subjects the water to a chemical or physical process that improves or alters the water. SEE OR SEARCH THIS CLASS, SUBCLASS: 167.3, for liquid purification or separation apparatus comprising a closed circulating system with means to add a treating material not for a swimming pool or spa. 198.1+, for liquid purification or separation apparatus with means to add a treating material not in a closed circulating system. SEE OR SEARCH CLASS: 422,  Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing,   subclasses 255+ for physical type apparatus having means separating or dissolving a material constituent, particularly subclasses 261+ for liquid-solid contact means and particularly subclass 265 for buoyant holders.

167.12	Separator external to swimming pool or spa:
	This subclass is indented under subclass 167.1.  Apparatus in which the liquid purification or separation means is located outside of the swimming pool or spa. (1) Note. The liquid purification or separation means may be attached to the exterior of the swimming pool or spa or may be connected to the swimming pool or spa by a system of pipes.

167.13	Particulate solid filter:
	This subclass is indented under subclass 167.12.  Apparatus in which the liquid purification or separation means comprises a plurality of small, distinct, separate, nonfilamentous solids in which a component of the water is entrapped and retained while permitting the water to pass through (e.g., sand filter, etc.).

167.14	With separator cleaning means (e.g., backwash means, etc.):
	This subclass is indented under subclass 167.12.  Apparatus in which means are provided to remove the separated component from the liquid purification or separation means.

167.15	Separator for use on swimming pool or spa bottom and separator for use at water surface:
	This subclass is indented under subclass 167.1.  Apparatus that has two or more means for liquid purification or separation in which one means is located on a surface that is lowest in the swimming pool or spa during operation and another means is located at a surface of the water that is highest in the swimming pool or spa during operation.

167.16	Separator for use on swimming pool or spa bottom:
	This subclass is indented under subclass 167.1.  Apparatus that has means for liquid purification or separation located on a surface that is lowest in the swimming pool or spa during operation.

167.17	Debris collecting bag:
	This subclass is indented under subclass 167.16.  Apparatus in which the liquid purification or separation means comprises a usually flexible container that may be closed that is used to gather the component that is separated from the water.

167.18	Skimmer arm at skimmer opening at water surface:
	This subclass is indented under subclass 167.1.  Apparatus in which the liquid purification or separation means comprises a deflecting device that is positioned at a surface of the water that is highest at an opening of a weir in a wall of the swimming pool or spa and that diverts a portion of the water and debris into the opening.

167.19	Mesh or screen filter at or near water surface:
	This subclass is indented under subclass 167.1.  Apparatus in which the liquid purification or separation means comprises a material with an open network of interlacing threads or wires in which a component of the water is entrapped and retained while permitting the water to pass through and is located at or near a surface of the water that is highest in the swimming pool or spa.

167.2	Having floating means:
	This subclass is indented under subclass 167.19.  Apparatus having means to support buoyantly the mesh or screen filter at or near the water surface in the swimming pool or spa.

167.21	For aquarium:
	This subclass is indented under subclass 167.01.  Apparatus in which the liquid purification or separation means is adapted for use with a water-filled container in which aquatic animals are kept, with the container having one or more transparent portions so that the aquatic animals therein can be observed from the exterior. SEE OR SEARCH THIS CLASS, SUBCLASS: 416.2, for a filter, with a pump, gas pressure, or suction source, adapted for use in an aquarium. SEE OR SEARCH CLASS: 119,  Animal Husbandry,   subclasses 259+ for specific aquarium structure in combination with liquid purification or separation means.

167.22	Separator using living organism:
	This subclass is indented under subclass 167.21.  Apparatus in which the liquid purification or separation means includes an agent that has the ability to reproduce itself. (1) Note. For purposes of this subclass, living organism includes animals, plants, and microorganisms (e.g., bacteria, fungus, algae, etc.), but not enzymes. The organism may reproduce sexually, asexually, or by mechanical division (caused by external agents) and regeneration (e.g., layering or cloning, etc.).

167.23	Separator or part thereof associated with bottom of aquarium (e.g., means positioned under gravel, etc.):
	This subclass is indented under subclass 167.21.  Apparatus in which the liquid purification or separation means or a portion thereof (e.g., an inlet or an outlet, etc.) is located at or near a surface that is lowest in the aquarium (e.g., means positioned under gravel, etc.).

167.24	Having solid sorbent:
	This subclass is indented under subclass 167.23.  Apparatus having a solid sorbent that is used to retain on its internal or external surfaces a component of the water passing in contact therewith. (1) Note. A solid sorbent is a solid material that separates one or more components from a fluid mixture containing such components in a "quasi-chemical" manner. The action in most instances is that of selective retention (i.e., the sorbent removes only that part of the fluid mixture for which it has the greatest affinity). The retained component cannot be removed by shaking, brushing, or similar mechanical action, but can generally be removed by heating, pressure reduction, or use of a stripping or denuding fluid. A filter has no particular "chemical" affinity for a component of a fluid mixture. The separation in the case of a filter depends on a mechanical entrapment of solid particles because of their relatively large size compared with the interstices or spaces between individual elements of the filter. The retained particles can be removed by brushing, wiping, shaking, or similar mechanical action.

167.25	Particulate filter or particulate sorbent:
	This subclass is indented under subclass 167.21.  Apparatus in which the liquid purification or separation means comprises a plurality of small, distinct, separate, nonfilamentous solids in which a component of the water is entrapped and retained while permitting the water to pass through or apparatus having a solid sorbent that is used to retain on its internal or external surfaces a component of the water passing in contact therewith. (1) Note. A solid sorbent is a solid material that separates one or more components from a fluid mixture containing such components in a "quasi-chemical" manner. The action in most instances is that of selective retention (i.e., the sorbent removes only that part of the fluid mixture for which it has the greatest affinity). The retained component cannot be removed by shaking, brushing, or similar mechanical action, but can generally be removed by heating, pressure reduction, or use of a stripping or denuding fluid. A filter has no particular "chemical" affinity for a component of a fluid mixture. The separation in the case of a filter depends on a mechanical entrapment of solid particles because of their relatively large size compared with the interstice or spaces between individual elements of the filter. The retained particles can be removed by brushing, wiping, shaking, or similar mechanical action.

167.26	Separator with aerator:
	This subclass is indented under subclass 167.21.  Apparatus in which the liquid purification or separation means is combined with means to supply the water with a gas (e.g., oxygen, air, etc.).

167.27	Separator mounted on top edge of aquarium wall:
	This subclass is indented under subclass 167.21.  Apparatus in which the liquid purification or separation means is located on an upper rim of the aquarium.

167.28	For cooking oil system:
	This subclass is indented under subclass 167.01.  Apparatus in which the liquid purification or separation means is adapted for use with a cooking apparatus in which food articles or materials are supported or manipulated for heat treating by contact with a body of heated oil (e.g., deep fat fryer, etc.). SEE OR SEARCH CLASS: 99,  Foods and Beverages: Apparatus,   subclass 408 for a deep fat fryer type cooker with crumb or sediment segregation means.

167.29	Having magnetic treating means:
	This subclass is indented under subclass 167.01.  Apparatus having means that attract iron and certain other materials because of a surrounding field of force produced by the motion of its atomic electrons and the alignment of its atoms. (1) Note. The magnetic treating means generally is used to cause separation of iron-containing material from the liquid. However, the magnetic treating means may subject the liquid to a process that otherwise improves or alters the liquid (e.g., mixing, etc.). SEE OR SEARCH THIS CLASS, SUBCLASS: 167.03, for liquid purification or separation apparatus comprising a closed circulating system having magnetic treating means for a lubrication system. 222+, for liquid purification or separation apparatus including magnetic treating means not in a closed circulating system.

167.3	With means to add treating material:
	This subclass is indented under subclass 167.01.  Apparatus in which the liquid purification or separation means is combined with means to supply a substance to the liquid being purified or separated that subjects the liquid to a chemical or physical process that improves or alters the liquid. SEE OR SEARCH THIS CLASS, SUBCLASS: 167.11, for liquid purification or separation apparatus comprising a closed circulating system with means to add a treating material for a swimming pool or spa. 198.1+, for liquid purification or separation apparatus with means to add a treating material not in a closed circulating system.

167.31	Plural separators:
	This subclass is indented under subclass 167.01.  Apparatus that has two or more means for liquid purification or separation.

167.32	With heating or cooling means:
	This subclass is indented under subclass 167.01.  Apparatus that has means to raise or lower the temperature of the liquid. SEE OR SEARCH THIS CLASS, SUBCLASS: 167.06, for liquid purification or separation apparatus comprising a closed circulating system with heating or cooling means for a lubrication system. 175+, for liquid purification or separation apparatus with a heater or a heat exchanger not in a closed circulating system.

170.01	Geographic:
	This subclass is indented under subclass 153.  Apparatus in which liquid purification or separation means are part of a system installed in the ground or related to a particular feature of the earth s surface (e.g., a body of water, etc.). (1) Note. Included in this subclass is in situ purging of flowing or still liquid (e.g., drainage ditch, septic system, pond, etc.) in a structural installation in which the liquid purification or separation means is (a) part of a system installed on natural or modified terrain to convey rain, snowmelt, a river, sewage, well water or oil, etc. or (b) related to a particular nonland geographic feature, such as a lake, ocean, sea, etc. SEE OR SEARCH THIS CLASS, SUBCLASS: 154+, for a flume stream type separator. SEE OR SEARCH CLASS: 137,  Fluid Handling,   subclass 236.1 for a distribution system involving a geographic feature. 405,  Hydraulic and Earth Engineering,   subclasses 36+ for drainage devices for collecting and removing surplus water from soil and subclasses 52+ for fluid control, treatment, or containment.

170.02	For fishpond:
	This subclass is indented under subclass 170.01.  Apparatus in which the liquid purification or separation means is adapted for use with a small, still body of clear water stocked with fish. SEE OR SEARCH CLASS: 119,  Animal Husbandry,   subclasses 226+ for a fish enclosure of the recirculating type with treatment means and subclasses 228+ for a fish enclosure of the nonrecirculating type with treatment means.

170.03	For stormwater treatment (e.g., rainwater runoff, stormsewer treatment, etc.):
	This subclass is indented under subclass 170.01.  Apparatus in which the liquid purification or separation means is adapted for use to subject fallen precipitation to a chemical or physical process that improves or alters the fallen precipitation (e.g., rainwater runoff, stormsewer treatment, etc.). SEE OR SEARCH THIS CLASS, SUBCLASS: 163+, for a grated inlet surface drain.

170.04	For excavating means:
	This subclass is indented under subclass 170.01.  Apparatus in which the liquid purification or separation means is adapted for use with an apparatus that digs, moves, and handles material either on the earth s surface or beneath a body of water. SEE OR SEARCH CLASS: 37,  Excavating,   for excavating apparatus.

170.05	Floating means:
	This subclass is indented under subclass 170.01.  Apparatus in which the liquid purification or separation means is buoyed on or in the liquid.

170.06	Separator with aerator:
	This subclass is indented under subclass 170.01.  Apparatus in which the liquid purification or separation means is combined with means to supply the liquid with a gas (e.g., oxygen, air, etc.).

170.07	Groundwater:
	This subclass is indented under subclass 170.01.  Apparatus in which the liquid purification or separation means purifies or separates water within the earth s surface. SEE OR SEARCH CLASS: 166,  Wells,   for well apparatus. 405,  Hydraulic and Earth Engineering,   subclasses 128.1+ for soil remediation.

170.08	Septic tank or waste liquid treatment system:
	This subclass is indented under subclass 170.01.  Apparatus in which the liquid purification or separation means comprises a tank in which a continuous flow of waste material is decomposed by bacteria or comprises a group of devices, including liquid purification or separation means, that purify or separate the waste liquid. SEE OR SEARCH THIS CLASS, SUBCLASS: 532.2, for a septic tank not associated with a geographic feature.

170.09	Body of freshwater (e.g., pond, lake, reservoir, etc.):
	This subclass is indented under subclass 170.01.  Apparatus in which the particular feature of the earth s surface that the liquid purification or separation means is related to is a bounded aggregate of still water that is not salty (e.g., pond, lake, reservoir, etc.).

170.1	Surface flowing freshwater (e.g., stream, river, ditch, canal, etc.):
	This subclass is indented under subclass 170.01.  Apparatus in which the particular feature of the earth s surface that the liquid purification or separation means is related to is a bounded aggregate of nonsalty, running water flowing on the earth s surface (e.g., stream, river, ditch, canal, etc.). SEE OR SEARCH THIS CLASS, SUBCLASS: 154+, for a flume stream type separator.

170.11	Body of saltwater (e.g., sea, ocean, etc.):
	This subclass is indented under subclass 170.01.  Apparatus in which the particular feature of the earth s surface that the liquid purification or separation means is related to is an aggregate of salt water covering most of the earth s surface (e.g., sea, ocean, etc.).

171	Machinery:
	This subclass is indented under subclass 153.  Apparatus including means having moving parts. SEE OR SEARCH THIS CLASS, SUBCLASS: 167.02 through 167.09 , for a closed circulating system for a lubrication system. SEE OR SEARCH CLASS: 68,  Textiles: Fluid Treating Apparatus,   subclass 208 for fluid textile treating means having a drain and strainer means associated therewith. 118,  Coating Apparatus,   subclass 610 for reconditioning by separation of coating materials. 134,  Cleaning and Liquid Contact With Solids,   subclass 104 for cleaning apparatus having material collectors (e.g., strainers) for escaping cleaning liquid.

172.1	Separator ancillary to storage tank:
	This subclass is indented under subclass 153.  Apparatus in which the liquid purification or separation means is auxiliary to a supply container.

172.2	Submerged separator:
	This subclass is indented under subclass 172.1.  Apparatus in which the liquid purification or separation means is covered with liquid.

172.3	On pump suction intake:
	This subclass is indented under subclass 172.2.  Apparatus in which the liquid purification or separation means is located on an inlet to a pump.

172.4	Filter supported by frame (e.g., bag shaped filter in fuel tank for engine, etc.):
	This subclass is indented under subclass 172.3.  Apparatus in which the liquid purification or separation means comprises a medium, in which a component of the liquid is entrapped and retained while permitting the liquid to pass through, that is held up by a skeletal structure (e.g., bag shaped filter in fuel tank for engine, etc.).

172.5	Having tethering means:
	This subclass is indented under subclass 172.2.  Apparatus in which the liquid purification or separation means is fastened to a part of the supply container by something (e.g., a rope or chain, etc.) with a set radius that allows the liquid purification or separation means to move about.

172.6	In tank inlet:
	This subclass is indented under subclass 172.1.  Apparatus in which the liquid purification or separation means is located at the opening to the supply container.

173	COMMINUTING:
	This subclass is indented under the class definition.  Apparatus comprising unitary separators and means to comminute solids. SEE OR SEARCH THIS CLASS, SUBCLASS: 154+, for a flume stream type separator, per se. 359+, for a movable filter or separator which may break up "flocs" or residue incidental to agitation or material handling. 407, for a filter having means for agitation of the liquid. 769, for related processes. SEE OR SEARCH CLASS: 241,  Solid Material Comminution or Disintegration,   and see the reference to Class 210 in section 8 of the class definition.

174	Cylindrical strainer:
	This subclass is indented under subclass 173.  Apparatus in which the separating medium comprises a cylindrical filter medium. SEE OR SEARCH THIS CLASS, SUBCLASS: 161, for a revolvable flume screen strainer, per se. 402+, for a movable drum type filter.

175	WITH HEATER OR HEAT EXCHANGER:
	This subclass is indented under the class definition.  Apparatus having heat exchanging means comprising an imperforate heat transfer member, radiant heater or heat generator. SEE OR SEARCH THIS CLASS, SUBCLASS: 167.06, for liquid purification or separation apparatus comprising a closed circulating system for a lubrication system with heating or cooling means. 167.32, for liquid purification or separation apparatus comprising a closed circulating system with heating or cooling means. 768+, for separating processes with treatment of separated solids, and subclasses 774+ for separating processes involving treatment by heating or cooling. SEE OR SEARCH CLASS: 62,  Refrigeration,   for refrigeration means or steps combined with fluid cooling or gas liquefaction or solidification. For particular subclasses in Class 62 involving refrigeration and fluid separation, see the reference to Class 62 in the class definition of this class (210). 96,  Gas Separation: Apparatus,   appropriate subclasses for gas separation apparatus combined with heating or cooling means. 122,  Liquid Heaters and Vaporizers,   subclasses 379+ for processes and apparatus for cleaning liquid heaters or vaporizers or for purifying the water while the boiler is in operation. 126,  Stoves and Furnaces,   subclass 343.5 for melting furnaces which may include liquid separating means. 159,  Concentrating Evaporators,   subclass 42 for strainers or skimmers specialized for that class. 165,  Heat Exchange,   subclass 119 for a heat exchange with an ancillary filter. 202,  Distillation: Apparatus,   subclass 178 for combined distilland preheater and strainer, and subclasses 202+ for still with condensate treating means. 266,  Metallurgical Apparatus,   subclasses 277+ for apparatus for separating molten metal for undesired constituents.

176	Thermal diffusion:
	This subclass is indented under subclass 175.  Apparatus which separate a liquid mixture into two or more dissimilar fractions by subjecting a thin film of liquid mixture to a temperature gradient. SEE OR SEARCH THIS CLASS, SUBCLASS: 775, for related processes.

177	With treating fluid addition:
	This subclass is indented under subclass 175.  Apparatus having means for adding a treating fluid.

178	With mechanical agitator or movable separator:
	This subclass is indented under subclass 177.  Apparatus in which the separator is provided with a mechanical agitator or in which the separating medium is movable.

179	With mechanical agitator or movable separator:
	This subclass is indented under subclass 175.  Apparatus provided with mechanical agitating means or with means for moving a separator. SEE OR SEARCH THIS CLASS, SUBCLASS: 178, for similar structure with addition of treating fluid.

180	Vapor or gas removal:
	This subclass is indented under subclass 175.  Apparatus provided with means to remove vapor or gas. SEE OR SEARCH THIS CLASS, SUBCLASS: 472, for a vented filter.

181	Flow line connected in series with distinct separator:
	This subclass is indented under subclass 175.  Apparatus in which a heater or heat exchanger is connected in series by a flow line for the liquid under treatment. SEE OR SEARCH THIS CLASS, SUBCLASS: 252+, for other serially connected distinct treating or storage units.

182	Diverse separators:
	This subclass is indented under subclass 175.  Apparatus in which the separators are of different kinds. SEE OR SEARCH THIS CLASS, SUBCLASS: 294+, for other diverse distinct separators.

183	Common casing coaxial with heater:
	This subclass is indented under subclass 182.  Apparatus wherein the heat exchanger is coaxial with the casing enclosing the diverse separators.

184	For filter:
	This subclass is indented under subclass 175.  Apparatus wherein the separator is a filter.

185	Imbedded or between filter media:
	This subclass is indented under subclass 184.  Apparatus in which the heat exchanger is embedded in the filter medium or is sandwiched between filter media.

186	External of casing:
	This subclass is indented under subclass 184.  Apparatus wherein the heat exchanger is external of the means confining the liquid undergoing treatment.

187	Within gravitational separator:
	This subclass is indented under subclass 175.  Apparatus in which the heat exchanger is within a liquid holding container of a gravitational separator.

188	WITH GAS SEPARATOR:
	This subclass is indented under the class definition.  Apparatus combined with a gas or vapor separator, which is more than a mere vent and must (1) remove gases evolved during a treating operation or (2) treat gas removed from a Class 210 separator. SEE OR SEARCH THIS CLASS, SUBCLASS: 472, for a filter with vent means. 539, for a gravitational separator having a vent. SEE OR SEARCH CLASS: 96,  Gas Separation: Apparatus,   for apparatus for gas separation, per se. See the Class 210 class definition for an amplification of the line.

189	PLURAL CHAMBERS WITH MOVEMENT OF GRANULES THEREBETWEEN:
	This subclass is indented under the class definition.  Apparatus comprising means providing distinct chambers or areas for solid-liquid contact with means for circulating granular separatory material between at least two of the chambers. SEE OR SEARCH THIS CLASS, SUBCLASS: 268, for a separator having means providing gravity flow of particles therethrough. 270, for moving rehabilitation means which pick up and redeposit particles on the same bed. 271+, for surface traversing rehabilitation means for a particulate material bed.

190	WITH EXTERNAL SUPPLY MEANS FOR REGENERATING MEDIUM, E.G., WATER SOFTENING SYSTEM:
	This subclass is indented under the class definition.  Apparatus in which means is provided for the purpose of conveying, preparing or storing a liquid which is used to restore a chemical affinity of the separatory medium.

191	With pump, injector or siphon:
	This subclass is indented under subclass 190.  Apparatus including a pump, injector or siphon.

192	WITH PRELIMINARY CHEMICAL MANUFACTURE:
	This subclass is indented under the class definition.  Systems comprising means to make one or more of the chemical reagents used in the treatment combined with apparatus of this class. SEE OR SEARCH THIS CLASS, SUBCLASS: 715, for processes of seeding with sludge of the system. 716+, for processes including reagent manufacture. SEE OR SEARCH CLASS: 422,  Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing,   subclasses 186.8+ for ozonizers with preparatory or product treating means; and subclass 186.23 for arc or spark discharge reactors having preparatory or product treating means.

193	WITH PRECOAT ADDING OR APPLYING MEANS:
	This subclass is indented under the class definition.  Apparatus with means to apply an additional solid material usually discrete particles, as a coating to a filtering medium, the additional material then acting as a primary filtering medium. SEE OR SEARCH THIS CLASS, SUBCLASS: 503+, for diverse granular or fibrous filter materials. 506+, for a coated or impregnated filter material. 777+, for separating processes including use of a filter aid.

194	RECIRCULATION:
	This subclass is indented under the class definition.  Apparatus in which at least a portion of the fluent material is circulated in a closed circuit from and back to the separator. SEE OR SEARCH THIS CLASS, SUBCLASS: 167.01 through 167.32 , for a structural installation with a closed circulating system. 189, for separatory apparatus including means to circulate filter particles between plural chambers. 621+, 712+, 765, and 805, for separating processes including recirculation. 779, for processes with residual returned to prefilt. SEE OR SEARCH CLASS: 137,  Fluid Handling,   subclass 268 for infiltration means ancillary to a fluid handling system, and subclass 563 for a closed circulating system of general utility. 204,  Chemistry: Electrical and Wave Energy,   subclass 238 for an electrolytic cell which includes a filter and recirculating means.

195.1	Serially connected distinct treating or storage units:
	This subclass is indented under subclass 194.  Apparatus including two or more vessels connected in series or two or more zones in a single vessel separated by a baffle connected in series. (1) Note. The vessels or zones may be either functionally or physically distinct from one another.

195.2	With semipermeable membrane, e.g., dialyzer, etc.:
	This subclass is indented under subclass 195.1.  Apparatus including a septum selective as to composition.

195.3	With sediment recycle means directly to main stream:
	This subclass is indented under subclass 195.1.  Apparatus including means to return sediment to a point upstream with respect to the flow of material to be treated, which means provides for recombination of the sediment with the material to be treated.

195.4	Means is baffle slot:
	This subclass is indented under subclass 195.3.  Apparatus in which the means to return sediment is an aperture in a wall dividing a vessel into separate treating zones.

196	Of filtrate:
	This subclass is indented under subclass 194.  Apparatus in which filtrate is returned to prefilt. SEE OR SEARCH THIS CLASS, SUBCLASS: 409+, for a filter with fluid cleaning involving mere return of filtrate for backwashing.

197	From bottom of separator:
	This subclass is indented under subclass 194.  Apparatus in which the material recirculated is removed from a bottom portion of the separator. SEE OR SEARCH THIS CLASS, SUBCLASS: 713, for processes of precipitation including return of removed solids to the separator.

198.1	WITH MEANS TO ADD TREATING MATERIAL:
	This subclass is indented under the class definition.  Apparatus combined with means to add a treating material. (1) Note. By "treating material" is meant (a) a material, usually a fluid, having a function other than rehabilitating a separating medium or cleaning a separator, (b) a fluid merely serving as a source of pressure, or (c) a fluid not in itself serving as a separating medium. SEE OR SEARCH THIS CLASS, SUBCLASS: 96.1+, for separators with constituent mixture variation controls. 101, for flow fluid pressure or material level proportional feed means. 105, for diverse sensing including control means for an auxiliary liquid inlet. 127, for a float controlled valve controlling an additional fluid inlet. 151, for a separator and gas-liquid surface contact means. 167.11, for liquid purification or separation apparatus comprising a closed circulating system for a swimming pool or spa with means to add a treating material. 167.3, for liquid purification or separation apparatus comprising a closed circulating system with means to add a treating material. 177+, for separators with a heater or heat exchanger and treating fluid addition means. 192, for a separator with preliminary chemical manufacturing means. 296, and 511, for separators using a liquid as a separating medium. 601+, particularly subclasses 11 and 15+, for processes of teating by living organisms. 633, and 634+, for processes of extraction from liquid by solvent or solute. SEE OR SEARCH CLASS: 137,  Fluid Handling,   subclasses 87.01+ for self-proportioning and correlating systems; and subclass 268 for holders for materials to be entrained into a fluid handling system. 261,  Gas and Liquid Contact Apparatus,   subclasses 2+ for such apparatus combined with means for separating constituents from the contact liquid; and subclasses 75+ for gas and liquid contact devices, per se. 422,  Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing,   for extracting, leaching, or dissolving apparatus. 423,  Chemistry of Inorganic Compounds,   appropriate subclasses for extracting, leaching, or dissolving processes therein provided for; and subclass 658.5 for extracting, leaching, or dissolving processes not otherwise provided for.