Abstract: The treatment system provides a feature that may reduce cost of the electrochemical plating process by reusing the virgin makeup solution in the spent electrochemical plating bath. The treatment system provides a rotating filter shaft which receives the spent electrochemical plating bath and captures the additives and by-products created by the additives during the electrochemical plating process. To capture the additives and the by-products, the rotating filter shaft includes one or more types of membranes. Materials such as semi-permeable membrane are used to capture the used additives and by-products in the spent electrochemical plating bath. The treatment system may be equipped with an electrochemical sensor to monitor a level of additives in the filtered electrochemical plating bath.

Abstract: A filter element for liquid filtration has a hollow-cylindrical filter medium body and an end disk covering an end face of the filter medium body. A central cutout axially penetrates the end disk. An outflow channel for liquid to be filtered or filtered liquid is arranged at the end disk and connects to a liquid collecting space. The outflow channel extends from a radially outward wall surface of the filter medium body to the central cutout of the end disk. The outflow channel is controlled by a drainage device. A filter device with a filter housing provided with such a filter element has a drainage device that controls the outflow channel. A filter device with a drainage device having a first drainage position for draining only water and a second drainage position draining water from a water collecting space and liquid from a liquid collecting space is provided.

Abstract: A filter device is configured to filter a liquid. The filter device includes a drum sized to receive the liquid and a plurality of filter panels coupled to the drum to define a plurality of discs. The liquid passes through at least a portion of one of the discs. Each filter panel includes a perimeter frame that defines a panel normal flow area and a filter media coupled to the perimeter frame. The filter media may be adapted to include a plurality of pleats.

Abstract: A filter device having a vent device for inhibiting formation of a vacuum in the filter device. The filter device includes a drum for receiving the liquid wherein the drum includes a drum headspace. The filter device also includes filter sets for filtering the liquid. The drum is rotated to enable cleaning of filter media. The filter device also includes a frame having spaced apart supports for supporting each of the filter sets. A fluid passageway extends between the supports, wherein the fluid passageway provides fluid communication between the tank headspace and a filter set to vent a filter set.

Abstract: A liquid reclamation assembly is provided for processing a lubricant or other liquid. The assembly includes a housing interior for receiving a filter subassembly. A manifold is in fluid communication with a discharge region of the filter subassembly, the manifold comprising a primary manifold passage for passage of source fluid and a series of draw ports. The cross sectional area of the primary manifold passage is greater than the total cross sectional area of the series of draw ports to create a venturi effect to draw fluid through the assembly. The filter subassembly includes a series of target filtration segment, each segment being designed for a specific reclamation process. An entry manifold governs and distributes the fluid to each of the target filtration segments. Results of an analysis of the fluid can be used to determine which target filtration segments are desired for processing the fluid. Valves within the entry manifold can direct the flow accordingly.

Abstract: A filter device having a vent device for inhibiting formation of a vacuum in the filter device. The filter device includes a drum for receiving the liquid wherein the drum includes a drum headspace. The filter device also includes filter sets for filtering the liquid. The drum is rotated to enable cleaning of filter media. The filter device also includes a frame having spaced apart supports for supporting each of the filter sets. A fluid passageway extends between the supports, wherein the fluid passageway provides fluid communication between the tank headspace and a filter set to vent a filter set.

Abstract: A filter device for filtering a liquid which includes trash. The device includes a drum for receiving the liquid and trash, wherein the drum includes at least one drum aperture. The device further includes a first pair of filter panels which are adapted for filtering the liquid. The filter panels are spaced apart to form a cavity for receiving the liquid and trash. The device further includes a frame for supporting the filter panels, wherein the frame is coupled to the drum. The frame includes a frame aperture wherein the frame aperture and the cavity form a volume having a cross sectional area sized substantially equal to or greater than the drum aperture and wherein said volume extends to a second pair of filter panels to enable liquid and trash which pass through the drum aperture to also pass through the frame aperture to the second pair of filter panels.

Abstract: The present invention relates to a filter pack formed by stacking rings, being used as a final element in multistage or single-stage filters. The filtration process is performed by consecutively separating the particles in suspension according to the thickness thereof in different areas.

Abstract: An extracorporeal blood machine includes a blood circuit; an access device enabling the blood circuit to be connected to a patient; first and second coupling devices for connecting to first and second tubes of the circuit; first and second electrodes held by the first and second coupling devices to contact blood flowing through the blood circuit, the electrodes enabling an electrical signal to be injected into the circuit; first and second contact members contacting the first and second electrodes, wherein at least one of the coupling devices includes a stem portion enabling at least one of the first and second contact members to contact at least one of the first and second electrodes, respectively, on an outer portion of the at least one electrode without disturbing blood flowing through the coupling device; and electronics coupled operably to the first and second contact members for applying the electrical signal.

Abstract: A fluid filter system including a filter housing having an inlet chamber that surrounds the inner chamber that houses the filter cartridges. The filter cartridges are positioned in an involute configuration to channel rotationally inward flow of the fluid as it loses kinetic energy and velocity. The configuration provides superior filtering of fluids flowing therethrough and provides superior filter life.

Abstract: Particular aspects of the inventive technology may, in embodiments, relate to a fluid filter apparatus that includes a filtered fluid conduit that has a length that is at least three times a characteristic diameter; and a plurality of holes, wherein at least one of said holes has a first shape and engages an end cap during fluid filter operation, and wherein at least one other of said holes has said first shape and passes filtered fluid from outside of said filtered fluid conduit to a conduit interior during fluid filter operation.

Abstract: The present invention relates to a pressurized filtration plant that includes: a sealed tank (1) in which discs (2) are provided including filtering sectors (20) carried by a rotary shaft (3) and connected to collectors within said shaft, a dispenser (10) enabling the egress of filtrates, the discharge of spinning air and the intake of blowing air for releasing the spun cakes, at least one duct for supplying a liquid laden with solid particles, at least one duct or discharging the filtrates, and a hopper (1b) for recovering the solid particles, characterized in that the discs (2) are vertically arranged so that the lower portion thereof is submerged in buckets (4) covered with deflectors (41) and including means for scrapping solid material deposits on the outer walls thereof.

Abstract: Provided is a filtration cassette having a rigid body configured for externally supporting a filtration media disposed thereover and having at least one filtering surface configured with a flow path facilitating filtered fluid flow from a space extending between the filtration media and the filtering surface, and extending towards an outlet terminal. Also provided is a filtration segment including such a filtration cassette and where the filtration media is a filtration thread tensionally coiled over the filtration cassette at a multi-layered and tight configuration. Further provided are a plurality of such filtration segments which are configured into a disk-type assembly forming a filtration unit for a filtering system.

Abstract: A filtration system comprising a tank-like housing, accommodating a filtration assembly secured within the housing and extending between a respective raw fluid inlet port and a filtered fluid outlet port. The filtration assembly comprises one or more filter units secured over a main pipe disposed within the housing and configured between a fixed, operative position, and a manipulating position. The housing is configured with at least one re-sealable opening on a side wall thereof, through which the filter units are serviced at the manipulating position.

Abstract: A filtration array comprising a main raw fluid supply line and a main filtered fluid collecting line, at least one filtration flow path extending between the main raw fluid supply line and the main filtered fluid collecting line; each of the at least one filtration flow path is configured with a filtering assembly comprising a pair of filter units coaxially extending from a common manifold configured on the filtration flow path and is in flow communication with the main raw fluid supply line and the main filtered fluid collecting line, each of the filter units comprising a plurality of parallely disposed filter members.

Abstract: A fuel filter has a coalescent element for separating water from fuel, a prefilter element, a main filter element, and a common central tube, wherein the coalescent element, the prefilter element, and the main filter element are arranged sequentially along the common central tube. A fuel filter arrangement has a housing in which the fuel filter is arranged. The common central tube of the fuel filter is attached to the housing, wherein between the fuel filter and the housing an annular space is formed.

Abstract: The invention relates to a disc shaped filter element for filtering a liquid such as a polymer. The filter element comprising—a hub, said hub defining a central opening therethrough,—an upper filter medium and a lower filter medium, said upper filter medium and said lower filter medium extending radially outwards from said hub. The upper filter medium and the lower filter medium comprise a layered structure comprising a first layer and a second layer. The first layer comprises a non-sintered metal fiber fleece and the second layer comprises a layer of non-sintered metal powder particles. The first layer and the second layer are sintered together.

Abstract: A serviceable device for filtering lubricating oil includes an inlet and an outlet, a first filtering element and an absorption filtering element. The absorption filtering element is configured to absorb a fluidic contaminant present in the lubricating oil when in contact with the absorption filtering element. A flow path for the lubricating oil is from the inlet, through the first filtering element, and out the outlet. The flow path further includes lubricating oil contact with the absorption filtering element.

Abstract: A disc filter includes several triangular sectors that are connected from their neck section to the body of the disc filter. The sectors form a relatively thin disc that is rotated during filtration in a basin that contains a suspension to be filtered. The side surfaces of the sector have openings through which liquid in the suspension passes into several essentially radial flow channels inside the sector to flow on to the neck section and away from the sector. A separating wall is formed between two adjacent radial flow channels. Furthermore, the sector is made of two side elements, which are of plastic material and the mating surfaces of which are placed against each other.

Abstract: A filtration vessel is provided with improved sealing surfaces and alignment methods. The sealing surface is provided by a perforated sleeve within the filtration vessel. An alignment mechanism is provided which allows for improved servicing of the filtration vessel.

Abstract: The invention relates to a filter device, in particular for fluids polluted with admixtures of water, such as diesel oil, comprising a filter housing (1) which has a fluid inlet (43) and a fluid outlet (44) and in which at least one filter element (9) can be received. During the filtering process, the respective fluid can flow through the filter medium (11) of the filter element from the unfiltered side (14) to the filtered side (13) of the filter medium, which surrounds an inner filter cavity (17). On at least one side of the filter medium (11), a water-separating system (23) having a separating region (25) for separated water is present. The water separating system is connected via at least one water opening (35) that is open toward the separating region (25) to a water collecting chamber (45), and the filter element (9) has a passage (29) that forms a fluid connection to the inner filter cavity (17) and can be connected to an element receptacle (47) of the filter housing (1).

Abstract: Embodiments of the invention provide a filter vessel including a housing with an inlet and an outlet, a toroidal-shaped inlet manifold, and a plurality of inlet channels. The toroidal-shaped inlet manifold is in fluid communication with the inlet and is positioned along a circumference of the housing, and the plurality of inlet channels are in fluid communication with the toroidal-shaped inlet manifold.

Abstract: A lubricant reclamation configuration includes a series of fluid inlets that distribute the fluid to a series of parallel arrangement of individual filter assemblies. A filter control valve assembly is assembled between the distribution manifold and each respective filter assembly individually controlling fluid flow between the distribution manifold and each respective filter assembly. The filter assembly processes the fluid. The processed fluid is collected and retuned to the system via a series of collection channels. The distribution manifold is preferably fabricated of a series of plates.

Abstract: The horizontal ore filter has a plurality of filter elements covering the circular filter surface thereof and a sub-frame supporting the filter surface. In one aspect, each filter element has a longitudinal concave curvature therein. In another aspect, each sector frame has side flanges thereon. The sub-frame has a plurality of T-bars extending radially along the circular filter surface and each one of these T-bars supports the side edges of two adjacent filter elements. Upon installation of the filter elements to the sub-frame, the sector frames are held tight against the T-bars to ensure a good seal between adjacent filter elements and between each filter element and the sub-frame of the machine.

Abstract: The invention relates to a filtration cell that comprises a tank with a bottom wall (2) and four side walls extending upwards from the bottom wall as well as an upward opening, the four side walls including two opposite longitudinal walls (3, 5) as well as a front facing wall (4) and a rear facing wall connecting them, a filtration bed (7) supported in the tank, an outlet opening for discharging the filtrate, and a covering flap (24) protruding outwards from the top of one of said longitudinal walls, the longitudinal wall (5) opposed to that fitted with the flap including a lower portion (25) extending upwards from the bottom wall (2) and an upper portion (26) extending slantedly upwards and inside the tank from the top of said lower portion (25), and/or the front facing wall (4) comprises a bottom portion (27) extending upwards from the bottom wall (2) and a top portion (28) extending slantedly upwards and inside the tank from the top of said bottom portion (27).

Abstract: The present invention relates to a filter pack formed by stacking rings, being used as a final element in multistage or single-stage filters. The filtration process is performed by consecutively separating the particles in suspension according to the thickness thereof in different areas.

Abstract: A fluid treatment assembly defines a treatment chamber and includes a treatment sub assembly positioned in an assembled condition in the treatment chamber. The treatment sub assembly includes a plurality of treatment members. The treatment assembly is arranged so that in use a fluid for treatment flows through the treatment members.

Abstract: A fluid filter system including a filter housing having an inlet chamber that surrounds the inner chamber that houses the filter cartridges. The filter cartridges are positioned in an involute configuration to channel rotationally inward flow of the fluid as it loses kinetic energy and velocity. The configuration provides superior filtering of fluids flowing therethrough and provides superior filter life.

Abstract: An apparatus for filtering liquid that includes a filter having an external surface; a rotatable shaft extending through the filter; and a movable member coupled to the rotatable shaft. The movable member is configured to impart a suction force at various locations across the external surface of the filter. The movable member has a trailing portion that extends further than the leading portion in the direction toward the filter.

Abstract: A solvent filtration and recovery system for filtration and recovery of a solvent-based liquid used in dry cleaning includes filtration tank having filter chamber with motor-driven spin filters which are selectively operated. A valve and conduit arrangement allows the liquid from dry cleaning to enter the filter chamber for filtering and flows out as filtered liquid while the spin filters are not rotating. The arrangement allows initial at least partial draining of the solvent-based liquid in the filter chamber after such filtration procedure. A recovery tank is in communication with the filtration tank through a main drain. A motor drives the spin filters during a recovery procedure, in which centrifugal force caused by the rotating spin filters for a predetermined amount of time removes by-product from the spin filters, which is drained off from the filtration tank. A reservoir stores the solvent-based liquid and receives the liquid from both the recovery tank and the filtration tank.

Abstract: Particular aspects of the inventive technology may, in embodiments, relate to a fluid filter apparatus that includes a filtered fluid conduit that has a length that is at least three times a characteristic diameter; and a plurality of holes, wherein at least one of said holes has a first shape and engages an end cap during fluid filter operation, and wherein at least one other of said holes has said first shape and passes filtered fluid from outside of said filtered fluid conduit to a conduit interior during fluid filter operation.

Abstract: Fluid treatment arrangements and methods for making and using fluid treatment arrangements are disclosed. A ribbon including a permeable fluid treatment medium may be spirally wound in a plurality of windings to form a fluid treatment element having a disk-shaped body. The disk-shaped body may include opposite end surfaces, an inner rim, and an outer rim. Up to one hundred or more fluid treatment elements may be positioned along a core assembly, and a surround may be positioned around the fluid treatment elements. The fluid treatment elements may be sealed to the core assembly with the inner rims covering openings in the core assembly, or the fluid treatment elements may be sealed to the surround with the outer rims covering openings in the surround. A fluid treatment arrangement may be contained in a housing to form a fluid treatment assembly. The housing may include an inlet port and an outlet port and may define a fluid flow path between the inlet port and the outlet port.

Abstract: A melt filter, for the purification of plastic melts, particularly dispensed from extruders, comprises a housing (1) with a melt channel (10), connecting a melt inlet (7) to a melt outlet (9), with a sieve disc (5), which may be rotated by a motorised ratchet drive provided in the melt channel (10), comprising recesses separated by ridges in a circular track for housing exchangeable filter elements and the housing (1) has a filter element changing station (13). The aim of ethinvetion is that the above shall be designed such that large amounts of melt for filtering can be filtered in a cost-effective energy saving and space saving manner. The above is achieved by means of the housing comprising at least two melt inlets (7, 8) connected to the melt outlet (9) by at least two melt channels (10, 11) and in each melt channel (10, 11) a sieve disc (5, 6) driven on rotation by a motorised ratchet drive is provided and each sieve disc (5, 6) is provided with a filter element exchange station (13, 15).

Abstract: The invention concerns a filter for liquids loaded with solid particles, comprising a vessel (52) provided with an inlet for the liquid to be filtered, an outlet for the filtrate emerging into a manifold and a discharge orifice for the sludge of solid particles and wherein is enclosed a plurality of filtering elements (10), each filtering element shaped like an elongated pocket (16) of fabric (12) of filtering media having an upper opening (10) in communication with the outlet and mounted around frames (18) provided with longitudinal drainage channels (30) and suspended to support elements housed in said vessel and comprising a radial pipe (20) forming a manifold wherein emerges the opening of the filtering elements. The invention is characterized in that the upper edge of said pockets is provided with a hem (17) receiving a stiffening element (19) and urged to be tightly fixed in a peripheral catching element (21) integral with said support elements.

Abstract: A filter layer includes at least partially gas-permeable material having a plurality of segments joined to one another in such a way that the filter layer has non-parallel edges. Inexpensive manufacturing methods for such a filter layer, conical honeycomb bodies having the filter layer and particle-filtering exhaust gas purification apparatuses for motor vehicles, are also provided.

Abstract: A filter system includes a plurality of filter assemblies coupled to a common receiving chamber. Each filter assembly is arranged so that filtered water can flow into the receiving chamber under the influence of gravity and pressure from the difference in water level on the outside of the filter assemblies and the water level within the receiving chamber as maintained by a drain or pump within the chamber. Each filter assembly includes an upright intake tube having inlet openings spaced vertically along the intake tube. A filter housing surrounds each intake tube and is spaced from the intake tube by a distance sufficient to receive a filter element between the intake tube and the housing. A cap secures the top of the filter assembly so that all water passing into one of the inlet tube openings must have first passed through the housing and the filter element. Blocking devices are used to change one filter element while the filter system continues to operate via the other filter assemblies.

Abstract: A rotatable water treatment device including a hollow shaft and multiple filtering units is provided. The hollow shaft has an axis hole, an external wall and a plurality of through holes defined through the external wall and communicating with the axis hole. The multiple filtering units watertightly mounted on the external wall of the hollow shaft, and each of the filtering units includes a center hole, two clipping nets, a supporting net and two filtering membranes. The supporting net is mounted between the clipping nets and two filtering membranes sandwiches the clipping nets such that the filtering membranes can be prevented from sinking into the meshes of the supporting net with the pump effect to accelerate the conducting of the water-filtering.

Abstract: A candle filter assembly for a filter device includes, in an exemplary embodiment, a tubular core having an outer surface and an inner surface, and including a plurality of openings extending therethrough, a filter media supported by the core defining a core and filter media subassembly, and a drain pipe including a plurality of openings extending therethrough to permit fluid to flow between an outer surface of the drain pipe and the inside of the drain pipe. The drain pipe is located inside the core. The candle filter assembly also includes an end cap, a first sealing block including a drain pipe opening. The drain pipe extends through the drain pipe opening in the first sealing block. The candle filter assembly further includes a compression nut threadingly engaging the drain pipe extending through the first sealing block.

Abstract: A method and apparatus for filtering a large volume fluid intake system using a modular immersed-filtration array that can be easily scaled for use in a wide variety of immersion filtering applications. The immersed-filtration array is composed of a plurality of individual filtration modules. Each filtration module has a mating end that allows the module to be coupled with a base unit or plenum via a common interface port located on the base unit. The array can be scaled in a plurality of ways.

Abstract: A filtration device for filtration, comprising at least one filter unit in a closed filter housing, comprises at least one filtration station and a loading and removing station. The filter housing can be opened in at least one parting plane transversely to the longitudinal axis of the filter housing and is movable between the loading and removing station and the filtration station.

Abstract: The present invention relates to a filter module comprising a body of wound layers of a sheet material, said sheet material having a plurality of openings formed therein, said openings forming two types of channels within the wound layers of sheet material of said body, said channels extending in a direction from the inner peripheral surface to the outer peripheral surface, a first type of channels being open at one end at said outer peripheral surface of the body and closed at the other end located adjacent to said inner peripheral surface, a second type of channels being open at one end at said inner peripheral surface of the body, and closed at the other end located adjacent to said outer peripheral surface, said channels of the one type being separated from the channels of the other type by portions of sheet material, wherein the sheet material has areas at the edge of the openings forming the inlet channels the thickness of which being smaller than the thickness of the sheet material remote from those op

Abstract: A panel sector, for a disc filter for separation of liquids from a suspension, includes front and back filter panel assemblies, a sector assembly for mounting the front and back filter panel assemblies, and a top cap for retaining the filter panel assemblies within the sector assembly. Each of the filter panel assemblies includes a frame and a filter material clamped by the frame. The sector assembly includes an outer end plate, an inner core mounting plate subassembly for mounting the panel sector to the disc filter core, first and second side channel subassemblies, at least one structural member extending radially between the core mounting plate subassembly and the outer end plate, and at least one support member extending laterally between the first and second side channel subassemblies. The core mounting plate subassembly and each of the side channel subassemblies have front and back channels for receiving portions of the frame.

Abstract: The invention relates to a method and a device for degassing of suspension, specifically fiber stock suspension. The method according to the invention is characterized in that separated excess suspension is discharged sideways through an overflow having an overflow edge that is located in the tank outside wall and is positioned parallel to the tank axis. The device according to the invention is characterized in that the overflow includes at least one overflow having an overflow edge that is located in the tank outside wall and is positioned parallel to the tank axis and that at least one overflow system, for the purpose of discharging the separated excess suspension, is located following the overflow.

Abstract: A filter unit is disclosed suitable for use in a filter housing. The filter unit comprises superposed and spaced-apart inclined lamellar structures, preferably in the form of hollow truncated cones, each having a lower end side opposite an upper end side and a passage for a flow of liquid between each two of the lamellar structures. Each passage has an inlet for receiving an inflow of liquid to be filtered and an outlet for discharging an outflow of filtered liquid. In each of the passages, an overflow dam wall following a sinuous path is obstructing the flow of liquid and retains particulate matter contained in the liquid. The filter unit is mounted vertically in a filter housing. The invention also concerns a prefilter comprising a filter unit as described above mounted vertically in a filter housing.

Abstract: In a particularly noise-free and vibration-free operating precoated filter for filtering for example cooling lubricating flowing media, a filter candle surrounding a riser channel is mounted by means of a riser tube in a separating plate in an axially moveable manner. A filter cake adhering to the outside of the filter candle is loosened in such a manner that for example a disk-shaped rotary body comprises a shoulder between the track end and the track start along its track. As soon as a head end piece connected to the riser tube and moveable in an axial manner against the force of a spring is released from the rotating track end, the stored force of the spring accelerates the filter candle, so that the filter cake adhering to the filter candles is loosened by the acceleration of the filter candle and the impact pulse when a dampening ring arranged between the filter candle and the separating plate abuts the separating plate.

Abstract: A high shear rotating disc filter having a hollow interior and constructed of a porous material such as sintered metal or ceramic with finely structured openings. The disc is mounted and secured onto a hollow shaft. The hollow shaft is connected to a vacuum source, external to the filter, that allows for the passage of the filtrate to a receiver. There are elongated slots in the wall of the shaft which provide the passage of filtrate from the disc. The shaft provides rotational force for the discs.

Abstract: A media bed support grid for use with a vessel having an inner surface. The media bed support grid comprises a plurality of filter panels, each filter panel having a plurality of parallel and spaced-apart filter wires, the plurality of filter wires forming a filtering surface. The media bed support grid also comprises a plurality of channels underlying and positioned substantially perpendicular to the filter wires. The media bed support grid further comprises a plurality of manifolds, each manifold being coupled to and in fluid communication with the channels.

Abstract: A continuous fluid filtration device having filtration cells disposed in a carousel around a rotation axis so as to be able to pivot about a tilt axis including apparatus for discharging the filtrate from the cells with at least one outlet orifice at the bottom of each cell, a central collector and a connection allowing flow of the filtrate between the outlet orifice and the collector, where the connection for each cell includes a flexible conduit in which, in the filtration position of the cell, no area of the flexible conduit is lower than another area of the conduit situated downstream with respect to the flow of the filtrate, the flexible conduit being arranged so as not to undergo any elongation during tilting of the cell.

Abstract: A filter element assembly has at least two cylindrically shaped and concentrically arranged filter media sleeves each connected at one end thereof to an inlet plate and each connected at the other end to a closed end terminal plate. Openings are provided in the inlet plate to permit entry of liquid to be filtered into the annular space between the filter sleeves. The closed end terminal plate prevents flow of unfiltered liquid from the annular space between the sleeves so as to force the liquid through the porous media of the sleeves to effect filtration. The inlet plate includes a central area that is recessed in relation to its outer edge to define an inlet chamber capped by a planar housing lid. The inlet chamber communicates with the inlet conduit via an opening in the central area.

Abstract: A caged filter cartridge assembly has a pair of coaxially spaced-apart end plates, and a number of tubular filter cartridges extending between said end plates. These end plates include seat recesses having a coaxially disposed retaining ring establishing an annular terminal lock edge. The filter cartridges include end caps at each opposed end thereof which are received within respective ones of said seat recesses. The end caps have at least one annular lock ring which is forcibly engaged with the terminal annular lock edge of the retaining ring so as to join the end cap, and thus said filter cartridge, to the end plates.