Abstract: A filter cartridge includes a substantially cylindrical filter media and a pressure relieving structure. The filter media is adapted to allow fluid to pass from an exterior of the filter media to an interior space of the filter media. The pressure relieving structure is disposed at an upper end of the filter media, and the pressure relieving structure opens when a predetermined pressure level is established across the filter media to maintain the predetermined pressure across the filter media.

Abstract: A filtration device and method for removing pollutants from fluid such as storm-water. The filtration device has a chamber including a series of pivotal filtration assemblies each including a weir and filter. The filters are selected and positioned for sequentially filtering larger then smaller pollutant particles from the water flowing through the device. The weirs are configured and positioned for sequentially permitting water overflow of (and thereby taking off-line) the smaller-particle size filters then the larger-particle size filters from the water flowing through the device. And the filtration assemblies are pivotally mounted to the chamber walls and configured so that, when one of the filters becomes clogged, the water pressure against it causes that filter assembly to pivot into a bypass position permitting water to flow under it.

Abstract: A fuel filtration device includes a first filter normally used to filter foreign substances in fuel, a second filter used to filter foreign substances in fuel only in a state where a degree of clogging of the first filter is larger than a predetermined level, and a regulating device for regulating a flow of fuel through the second filter. The regulating device disables the flow of fuel through the second filter to limit the filtering of foreign substances through the second filter when the degree of clogging of the first filter is equal to or smaller than the predetermined level. The regulating device enables the flow of fuel through the second filter to permit the filtering of foreign substances through the second filter when the degree of clogging of the first filter is larger than the predetermined level.

Abstract: The invention relates to a fuel filter (1) with a device for separating water from the fuel. This device comprises at least one filter screen element (6) placed in a filter housing (2) which is located downstream a filter element (3) for the filtration of particles from the fuel, a tank (15) located under the filter screen element (6) at the filter housing (2) in which the separated water droplets are collected, and a device for deviating the fuel between the filter element (3) and the filter screen element (6).

Abstract: A return flow filtration assembly for filtering return hydraulic fluid is provided. The filtration assembly includes a first return fluid chamber including a first inlet and first and second of outlets. The second outlet is configured to be coupled to a secondary return flow filter for providing micro-filtering of the return fluid. The first outlet includes a restriction element for restricting flow through the first outlet and generating an artificial back pressure within the first return fluid chamber to drive fluid through the second outlet, when the second outlet is coupled to a secondary return flow filter.

Abstract: An apparatus that combines desalination and pressure washing. The apparatus includes separate inlets for seawater and for freshwater. The apparatus includes a first diverter valve to selectively permit the flow of seawater or freshwater into the apparatus. The apparatus also contains a second diverter valve for directing the flow of seawater or freshwater to a pressure-washer outlet for pressure washing or directing the flow of seawater to a desalination assembly such as a reverse-osmosis (RO) membrane for desalination. The apparatus contains one or more pumps sufficient to generate fluid pressure for pressure washing and generating a driving pressure across the desalination assembly. A variable frequency drive system may be included in the apparatus to regulate the RO pump flow rate across a fixed orifice thereby regulating driving pressure and in turn the freshwater production rate from the RO system.

Abstract: A fluid filter assembly having a relief valve for visually indicating when a filter element may be replaced. The fluid filter assembly of the present invention provides a vertical, transparent housing having a fluid inlet for communicating a fluid into the housing and a fluid outlet for communicating fluid downstream of the housing. A filter element is disposed within the housing between the fluid inlet and the fluid outlet for filtering the fluid. The relief valve can also be in the form of a more restrictive filter media 42.

Abstract: A serial-flow filtration device is provided with pressure-activated means for by-passing at least one of its constituent layer (or layers) of filtration material. The filtration device comprises a housing, a fluid inlet, a fluid outlet, and at least an upper and a rearmost filter layer. The upper filter layer divides the interior of the housing into an upstream zone and a downstream zone, with the rearmost filter layer residing in the downstream zone. The fluid inlet enables the introduction of fluid into said upstream zone. The fluid outlet enables releases of the fluid from said downstream zone. The upper filter layer, but not the rearmost filter layer, has integrated thereinto a pressure-activated means capable of allowing substantially non-selective passage of fluid from the upstream zone into the downstream zone upon the attainment of a predetermined pressure differential across said upper filter layer.

Abstract: A fluid filter includes a vertical housing, a filter cartridge, and a bypass valve. The housing has a fluid inlet for communicating a fluid into the housing and a fluid outlet for communicating fluid downstream of the housing. The filter cartridge is disposed within the housing between the fluid inlet and the fluid outlet and includes a filter element for filtering the fluid, as well as means for maintaining and relieving a predetermined level of pressure across the filter element to provide an accurate visual indicator as to whether the filter element needs replacement. The bypass valve allows fluid to flow from an unfiltered side of the filter element to a filtered side of the filter element when the pressure across the filter element exceeds the predetermined pressure.

Abstract: A filter assembly includes a filter housing including an inlet, through which hydraulic fluid enters the housing, and an outlet, through which hydraulic fluid exits the housing, valve housing containing a bypass valve located adjacent the inlet in a chamber, the valve including an orifice that opens and closes in response to differential pressure across the valve, and a screen secured to the valve housing and covering the orifice, the screen having a fine mess for removing contaminants from the fluid that flows through the valve.

Abstract: A serial-flow filtration device includes a pressure-activated gate for by-passing at least one of its constituent layer (or layers) of filtration material. The filtration device includes a housing, a fluid inlet, a fluid outlet, and at least an upper and a rearmost filter layer. The upper filter layer divides the interior of the housing into an upstream zone and a downstream zone, with the rearmost filter layer residing in the downstream zone. The fluid inlet enables the introduction of fluid into the upstream zone. The fluid outlet enables releases of the fluid from the downstream zone. The upper filter layer, but not the rearmost filter layer, has integrated thereinto a pressure-activated gate capable of allowing substantially non-selective passage of fluid from the upstream zone into the downstream zone upon the attainment of a predetermined pressure differential across upper filter layer.

Abstract: A cleaning device for cleaning lubricating oil which circulates in a lubricating oil circuit has an intake to be connected with the lubricating oil circuit, through which a part quantity of the lubricating oil circulating in the lubricating oil circuit is to be fed to the cleaning and a return to be connected with the lubricating oil circuit for the returning of the cleaned lubricating oil into the lubricating oil circuit.

Abstract: A filter cartridge includes a substantially cylindrical filter media and a pressure relieving structure. The filter media is adapted to allow fluid to pass from an exterior of the filter media to an interior space of the filter media. The pressure relieving structure is disposed at an upper end of the filter media, and the pressure relieving structure opens when a predetermined pressure level is established across the filter media to maintain the predetermined pressure across the filter media.

Abstract: A liquid filter assembly is provided. The preferred assembly includes a serviceable filter cartridge having a primary filter section and a secondary or bypass filter section. The preferred assembly includes a bypass valve arrangement and a suction filter arrangement. The suction filter arrangement preferably includes a dimensionally biased valve arrangement, preferably one which is devoid of a helical coiled spring, to control flow through the suction filter. A flow/pressure regulation valve, to allow flow from an interior of the assembly to a reservoir if needed, is preferably provided. Preferred serviceable filter cartridges are shown.

Abstract: A diesel fuel filter comprising an outer casing (2) which is provided at leas with an inlet conduit (40) for the diesel fuel to be filtered (A) and an outlet conduit (41) for the filtered diesel fuel (B), and houses internally at least one first filtering baffle (70) of high filtering efficiency which separates the interior of said casing (2) into two separate chambers, of which a first chamber (8) communicates with the outlet conduit (41) and a second chamber (9) communicates with the inlet conduit (40); the filter (1) also comprises a third chamber (10), which is separated from said first chamber (8) by at least one second filtering baffle (71) permeable to thickened paraffins, and is separated from said second chamber (9) by means (78) arranged to connect said second chamber (9) to said third chamber (10) when the temperature of the diesel fuel to be filtered (A) falls below a value responsible for the formation of thickened paraffins.

Abstract: A filter system includes a set of modules, each module including screen assemblies and filter media sandwiched between the screen assemblies. A plurality of control assemblies are associated with each of the modules. Each of the control assemblies is in fluid communication with a corresponding module to control flow through the corresponding module. The control assemblies selectively control fluid in each of the modules between at least one of a forward flow through the screen assemblies to treat an influent flow, a bypass flow to bypass at least one of the modules, and a reverse flow to backwash a given filter media. A method of filtering influent includes providing an influent flow to a set of modules, each module including screen assemblies and filter media sandwiched between the screen assemblies. The influent is filtered by directing the influent through the set of modules. A given module is bypassed when the given module becomes occluded.

Abstract: A filtering apparatus having two distinct filter media for filtering circulating fluid in a circulation system. A portion of the fluid entering the filter passes through a first filter media, while a reduced portion of the fluid entering the filter passes through a second filter media. The second filter media accumulates contaminants and suspended particles from the circulating fluid. The filter media is capable of including at least one additive for treating the circulating fluid. Due to the reduced volumetric fluid flow through the second filter media, the additive can be slowly administered to the circulating fluid over a long period of time. The two filter media may be housed in a dual-canister, where the second filter media may be removed and replaced without removing the first filter media.

Abstract: An automatic transmission fluid (ATF) filtration system that combines both coarse filtering mesh and microfine depth filtering elements simultaneously to remove a wide range of particulate matter, but also maintains an unrestricted flow of ATF to the pump to ensure its volumetric efficiency is disclosed. In the present invention ATF at system pressure is delivered via a hydraulic circuit to a microfine depth filtering element for depth filtration (i.e. several layers of filter media) and, thereafter, is passed into the intake of the coarse filter element or, alternatively, between the intake of the coarse filter element and the pump intake. Because ATF flow through the coarse filter element is continuous and independent of the microfine depth filter element, the volumetric efficiency of the pump is maintained in all phases of operation even at the highest demand points such as at cold start-up, hot idle, and high volume/demand situations.

Abstract: A metallic particle trap bypass filter is disclosed generally comprising a housing, a filter element disposed therein, an inflow chamber, an outflow chamber, a bypass valve connecting these chambers, and a magnet disposed in the outflow chamber. In some embodiments, the magnet is a magnetic rod. In certain advantageous embodiments, a second filter element, with a different mesh size than the first filter element, is coupled to the first filter element. In some embodiments, the filter element in stainless steel, and in certain embodiments, the filter element is pleated.

Abstract: A filter device has a filter housing (10) receiving a first filter element (12), through which a medium may flow in a given direction, and has a bypass device (22). Along with the first filter element (12), a second filter element (32) is provided. The filter elements are arranged in series, one behind the other, in the direction of flow. When the bypass device (22) is activated, the second filter element (32), immediately following in the direction of flow, filters the medium. The second filter element thus takes over the main filtration of the medium on actuation and operation of the bypass device, since the first filter element is essentially no longer available for a filtration process due to the bypass device.

Abstract: A filter assembly including a primary flow passageway having at least one filter deployed therein and a secondary flow passageway having a bypass filter deployed therein is provided. The filter assembly further includes a bypass valve assembly configured to selectively open and close the secondary flow passageway when a fluid pressure is respectively above and below an adjustable, predetermined threshold value. Exemplary embodiments of this invention may be coupled to a drill string and advantageously utilized to filter drilling fluid downhole. Such embodiments tend to advantageously improve the filtering efficiency and safety of drilling operations.

Abstract: A fuel filter includes a first filter chamber, a second filter chamber and a valve assembly disposed between the first and second filter chambers. The valve assembly includes a valve casing with a valve head connected to a flag indicator slidably disposed within the valve casing and movable between a first and second position. A port located in the valve casing allows fuel to flow from the first filter chamber to the second filter chamber when the valve head and flag indicator moves from the first position to the second position. A transparent portion of the valve casing allows the flag indicator to be visible in the second position allowing a user to determine that the fuel filter must be serviced or removed and replaced.

Abstract: The present invention relates to small vehicles such as lawn and garden tractors and more specifically to an oil filter cartridge or assembly usable with the transmissions of such vehicles. The cartridge is comprised of a filtering element, a strainer element and a by-pass valve. The by-pass valve is housed within the strainer element and is adapted to direct oil flow through the strainer element, but not the filter element when the oil viscosity is high and only through the filter element when the oil viscosity is low. In this way, the parasitic horsepower loss caused by routing oil through the strainer element at all times is eliminated. The cartridge is also housed within the transmission case to reduce mounting bracketry outside the transmission case and minimize the likelihood of insufficient oil supply available for the filter, pump and hydraulic system functions.

Abstract: The present invention relates to small vehicles such as lawn and garden tractors and more specifically to an oil filter assembly used with the transmissions of such vehicles. The filter assembly is housed within the transmission case to reduce mounting brackets outside the case and minimize the likelihood of insufficient oil supply to the filter, pump and hydraulic system functions. The replaceable oil filter assembly is comprised of a filtering element, a strainer element and a by-pass valve. The by-pass valve is housed within the strainer element and is adapted to direct oil flow through the strainer element, but not the filter element when the oil viscosity is high and only through the filter element when the oil viscosity is low. In this way, the parasitic horsepower loss caused by routing oil through the strainer element at all times is eliminated.

Abstract: A filter (10) for filtering debris out of the fluid in a transmission sump (S) prior to the fluid entering a transmission pump (P) is disclosed. The filter (10) includes a filter housing (12) presenting a filter inlet (30), a bypass inlet (32), and an outlet (46). Filter media (14) is disposed in the housing (12) such that fluid flowing from the filter inlet (30) to the outlet (46) passes through the media (14) and fluid flows from the bypass inlet (32) to the outlet (46) without passing through the media (14). A bypass valve assembly (16), shiftable into and out of a closed position, prevents fluid flow through the bypass inlet (32) when the valve (16) is closed.

Abstract: A filter module assembly utilizes a priority valve installed in a manifold to allow for continuous filtration of hydraulic fluid up to a predetermined flow value and diverts occasional high flow to a secondary circuit. This arrangement provides both a low pressure drop at a high flow condition and structural integrity (1,000,000 impulse cycles from 0 to 6000 psi) while at the same time may reduce the weight by as much as 50% from a conventional design approach.

Abstract: A filter device is used to capture a desired amount of material suspended in a liquid or gas. The device includes a planar filter 530 mounted in a chamber defined by a body member having an upper body 510, a lower body 520, an inlet port 525, and an outlet port 515. The filter includes porous portions 540 and 545. Porous portion 545 is centrally arranged and is more restrictive to flow than portion 540. The filter is designed such that upon portion 540 capturing a desired amount of material, a predetermined pressure change exists across the filter. The predetermined pressure change causes the filter to deform and conform against an inner surface of the upper body resulting in all suspension flowing through the apparatus to flow through the more restrictive second portion 545.

Abstract: A two-stage, retrofit filter is adapted for use with an electrical discharge machine (EDM) includes nested inner and outer filtering elements that may be placed as a unit in the same tank and over the apertured standpipe used for a one-stage filter, such that the fluid to be filtered now flows through each of the multiple filter elements. The retrofit EDM filter may be configured for flow in either direction, though the usual arrangement is one whereby the fluid being filtered flows up through the bottom of the tank, out the apertured standpipe, and into the inner filter element. Preferably, the filter elements are cylindrical, pleated elements composed of a technical grade filter paper. In the preferred embodiment, a pressure-operated release valve is provided in conjunction with the inner filter, such that when a predetermined pressure is reached due to the entrapment of contaminants by the inner filter, the valve opens to allow the fluid to be filtered to flow through the outer filter.

Abstract: A fluid filter assembly having a relief valve for visually indicating when a filter element may be replaced. The fluid filter assembly of the present invention provides a vertical, transparent housing having a fluid inlet for communicating a fluid into the housing and a fluid outlet for communicating fluid downstream of the housing. A filter element is disposed within the housing between the fluid inlet and the fluid outlet for filtering the fluid.

Abstract: A replaceable cartridge type dual stage bypass valve is used in dual filter multi-media filtration assemblies. The cartridge may be selected and easily replaced to meet the various combinations and requirements of the dual filter elements (primary and secondary). The individual bypass valves that form the dual stage bypass valve may each be responsive to a predetermined increase of pressure due to a clogged filter condition. The individual bypass valves may use replaceable coil springs. The spring force of the coil spring is determined by the pressure differential to be resisted, i.e., the resistance to be offered by the spring action of the spring, and the flow capacity at a given pressure differential.

Abstract: A pipe mounting apparatus for a water filter includes a first half body with a top, a first pipe assembly, a second half body with a top, a second pipe assembly and a mounting bracket. The first pipe assembly is formed on the top of the first half body and has a pump inlet and a pump outlet. The second half body is attached to the first half body. Likewise, the second pipe assembly is formed on the top of the second half body and communicates with the first pipe assembly to form a water filtering loop. The mounting bracket is mounted over the two half bodies to support a booster pump. Consequently, the booster pump will be quickly and easily connected to the pump inlet and the pump outlet with fittings or pipes to pump the water into the water filter.

Abstract: The present invention relates to small vehicles such as lawn and garden tractors and more specifically to an oil filter assembly used with the transmissions of such vehicles. The filter assembly is housed within the transmission case to reduce mounting bracketry outside the case and minimize the likelihood of insufficient oil supply to the filter, pump and hydraulic system functions. The replaceable oil filter assembly is comprised of a filtering element, a strainer element and a by-pass valve. The by-pass valve is housed within the strainer element and is adapted to direct oil flow through the strainer element, but not the filter element when the oil viscosity is high and only through the filter element when the oil viscosity is low. In this way, the parasitic horsepower loss caused by routing oil through the strainer element at all times is eliminated.

Abstract: The present invention relates to small vehicles such as lawn and garden tractors and more specifically to an oil filter cartridge or assembly usable with the transmissions of such vehicles. The cartridge is comprised of a filtering element, a strainer element and a by-pass valve. The by-pass valve is housed within the strainer element and is adapted to direct oil flow through the strainer element, but not the filter element when the oil viscosity is high and only through the filter element when the oil viscosity is low. In this way, the parasitic horsepower loss caused by routing oil through the strainer element at all times is eliminated. The cartridge is also housed within the transmission case to reduce mounting bracketry outside the transmission case and minimize the likelihood of insufficient oil supply available for the filter, pump and hydraulic system functions.

Abstract: A system (11) for providing purified water comprises a plurality of individual modules, each of which includes a separable head (13) and a canister (17), which modules are joined one to another via these heads to create a composite manifold (15). The heads and canisters are respectively of substantially identical construction, and the hollow canisters include the following units: preheater, prefilter (25), pump (27), membrane purification (29), postfilter (31), and UV treatment. The overall system is monitored by a control unit (131) that is regularly interrogated by an off-site, headquarters computer, and both the control unit (131) and the headquarters computer are proactive in detecting potential difficulties that may be able to be readily remedied by promptly dispatching a serviceperson with a replacement for the canister containing the operating unit that requires replacement.

Abstract: A liquid filter (10) housing an annular filter element (16) has an annular space or inlet chamber (24) between the filter element and the housing and viewable through the housing such that an operator can see the level of liquid in the inlet chamber as an indication of when to replace the filter element, the higher the level of liquid in the inlet chamber the greater the pressure drop across the filter element. A change interval plugging indicator (102), preferably part of the filter element, is provided by a gas trap and pressure responsive release mechanism (104) trapping gas in the upper section (23) of the inlet chamber until a designated release pressure is reached, corresponding to a desired terminal pressure, to prevent premature plugging indication otherwise indicated by rising liquid level in the inlet chamber. Accurate and reliable calibration is enabled by separating the filtration function and the plugging indication function.

Abstract: A filtering device, especially a suction return filter includes a filter housing having two useful connections and a tank connection, and accommodates at least one filter element. The filter housing also provided with three return valves, two of which are held in the closing position by spring loads. All of the return valves are combined as a module at one end of the filter housing. The remaining return valve is configured as an integral constituent part of one of the spring-loaded return valves, has an opposite opening direction relative to it, and is not spring loaded. This arrangement enables the return valve unit to have a compact arrangement which can be structurally easily connected to the filter housing at a central point.

Abstract: The invention relates to a filter device with a filter housing (10) and a first filter element (12), arranged therein through which a medium may flow in a given direction and with a bypass device (22). Along with the first filter element (12), a further second filter element (32) is provided, said filter elements (32) are arranged in series, one behind the other, in the direction of flow and, on the bypass device (22) being activated, the further filter element (32), immediately following in the direction of flow, carries out a filtration of the medium. The further filter element thus takes over the main filtration of the medium on actuation and operation of the bypass device as the first filter element is essentially no longer available for a filtration process due to the bypass device.

Abstract: A replaceable cartridge type dual stage bypass valve is used in dual filter multi-media filtration assemblies. The cartridge may be selected and easily replaced to meet the various combinations and requirements of the dual filter elements (primary and secondary). The individual bypass valves that form the dual stage bypass valve may each be responsive to a predetermined increase of pressure due to a clogged filter condition. The individual bypass valves may use replaceable coil springs. The spring force of the coil spring is determined by the pressure differential to be resisted, i.e., the resistance to be offered by the spring action of the spring, and the flow capacity at a given pressure differential.

Abstract: A filter module assembly utilizes a priority valve installed in a manifold to allow for continuous filtration of hydraulic fluid up to a predetermined flow value and diverts occasional high flow to a secondary circuit. This arrangement provides both a low pressure drop at a high flow condition and structural integrity (1,000,000 impulse cycles from 0 to 6000 psi) while at the same time may reduce the weight by as much as 50% from a conventional design approach.

Abstract: A multiple stage fuel strainer assembly for a fuel tank in a vehicle includes a strainer adapted to be connected to an inlet of a fuel pump disposed in the fuel tank. The multiple stage fuel strainer assembly also includes a valve connected to the strainer to allow fuel to flow through the strainer to the inlet when an external surface of the strainer is restricted with contaminants in the fuel.

Abstract: A filter device for filtering hydraulic fluid includes first and second subelements 40, 42 within a filter housing having separate inflows 20, 24 thereto for the respective subelements and a common outflow 22. The first subelement has a higher filter fineness than the second subelement. Several bypass configurations are taught and include: (i) a bypass line 28 for bypassing the second subelement by drawing fluid directly from the supply 95; (ii) a bypass valve 116 (FIG. 3) for bypassing the first subelement; and (iii) a bypass valve 151 (FIG. 5) for connecting the first subelement inflow 20 with the common outflow 22. The device is compact, has an easy-to-service arrangement, and ensures protection of a hydraulic pump and highly stressed hydraulic components.

Abstract: An oil filter includes a housing 14 having an end plate 20 attached to the open end thereof. The end plate 20 includes an outlet opening and inlet openings 22. An anti-drainback valve 49 is provided adjacent the end plate. A filter element having an end cap at each end is positioned within the housing. The end cap 50 remote from the end plate includes a plurality of openings 52 spaced from a closed central portion 51. A spring valve 60 cooperates with the end cap 50 and the interior wall of the housing to alternately allow and disallow oil flow through the end cap openings depending upon the differential pressure across the end cap 50. The spring valve 60 and the end cap 50 can be operationally interengage to provide a relatively flat profile. Depressions 72 (FIG. 5) may be included between the arms 62 of the spring valve to provide a flow path should the spring valve be flattened against the housing during operation of the filter.

Abstract: A fluid filter assembly having a relief valve for visually indicating [the life of] when a filter element may be replaced. The fluid filter assembly of the present invention provides a vertical, transparent housing having a fluid inlet for communicating a fluid into the housing and a fluid outlet for communicating fluid downstream of said housing. A filter element is disposed within the housing between the fluid inlet and the fluid outlet for filtering the fluid. In [the preferred] a first embodiment, a [frusto-conical] divider is connected to the top of the filter element and extends downward adjacent a bottom portion of the filter element wherein the fluid from the inlet rises between the filter element and the inside of the divider and between the outside of the divider and an inside surface of the housing. A relief valve is provided in the top of the filter element and is in communication with the unfiltered and filtered side of the filter element.

Abstract: A multiple stage fuel strainer assembly for a fuel tank in a vehicle includes a strainer adapted to be connected to an inlet of a fuel pump disposed in the fuel tank. The multiple stage fuel strainer assembly also includes a valve connected to the strainer to allow fuel to flow through the strainer to the inlet when an external surface of the strainer is restricted with contaminants in the fuel.

Abstract: A filtration system includes a magnetic drum for removing ferrous shavings and a dual canister filter unit equipped with replaceable filter bags. This palletized system may be plugged into most machine tools to filter the shavings-laden coolant to remove the metal shavings, tramp oil, sludge and dirt from liquid coolant to extend its useful life and minimize or eliminate down time.

Abstract: To develop a filter device for filtering a hydraulic fluid with a filter housing, in which a filter element is disposed, in such a way that it ensures protection of a hydraulic pump and highly stressed hydraulic components and has a compact, easy-to-service form of construction, it is proposed according to the invention that the filter element comprises a first and a second subelement, the first subelement having a higher filter fineness than the second subelement and both subelements being insertable through a common insertion opening into the filter housing, and that it is possible for hydraulic fluid to be fed to each subelement via a separate supply inflow and for filtered hydraulic fluid to be discharged from both subelements via a common outflow. Furthermore, a filter element and a hydraulic circuit for a filter device of this type are proposed.

Abstract: A filter unit for coupling in-line with a transmission fluid line is provided for filtering ferrous and non-ferrous particulate matter from the transmission fluid. The filter unit includes a filter element 21 situated within a casing 12. The filter unit has an annular magnet 26 mounted on an end thereof. In an operational condition, the magnet is seated against an inner surface of the casing. As the filter becomes clogged, the filter element moves to a bypass position unseating the magnet from the casing. Fluid then bypasses the filter element but still flows around the magnet which continues to attract and trap ferrous particulate matter. A ferrous indicator flag 49 may be positioned on the outside of the casing when the filter element is in its operational position and is released and falls away as a visual indication of a clogged filter element in the bypass position.

Abstract: A filter assembly for filtering pond or aquarium water includes a container (1,2) with an inlet chamber (15) having an upstream region (36) and a downstream outlet (13) leading to an outlet chamber (22). A filter (16) is positioned in the inlet chamber (15) between the upstream region (36) and the outlet (13). In use, progressive clogging of the filter causes the water pressure in the upstream region (36) to rise until it reaches a predetermined threshold when a normally-closed relief valve (28,29) opens to allow water to pass from the upstream region (36) to the outlet chamber (22) without passing through the filter (16). The valve has a coloured valve stem (28) providing a visual indication that the valve is open and that the filter is blocked and requires cleaning. In one embodiment, the outlet chamber (22) contains a source (19) of ultra-violet radiation to which the flow of water is exposed, regardless of whether the valve (28,29) is in the open or closed condition.

Abstract: The knock-down structure of the filter comprises a body with a cover and a filtering element with a bypass valve and an anti-drain valve, a filtering element of the bypass valve and a spring, arranged coaxially inside the body. The body is provided with an annular groove accommodating a split locking ring. On the external cylindrical surface of the cover at least one annular groove is provided in which a sealing gasket and a projection are disposed, said projection interacting with said split locking ring. The one-piece structure of the filter does not comprise a locking ring and projection, the body having a beading made at the end edge thereof and directed toward the interior of the body, the cover being made likewise with a sealing gasket, the external end surface of the cover interacting with the beading of the body.

Abstract: An apparatus for monitoring particulates in a liquid stream and the rate at which the particulates foul a filtering medium, generally a reverse osmosis membrane, to determine at what point in time the filtering medium should be cleaned or replaced. The apparatus includes a monitoring filter unit having a plurality of filter portions. The pressure drop across each filter portion, through which a sample of the feed stream is passed, is monitored. Fouling of a filter portion by accumulated particulate thereon causes an increase in the pressure drop across the filter unit. The increasing pressure drop is monitored as an indicator of the correlative or correspondent fouling of the main filtering medium to be protected. Different filter portions in the filter unit are successively used as each becomes fouled, allowing continuous monitoring for extended periods of time between filter media changes in monitoring filter unit.