EP0902717A1

EP0902717A1 - Safety relief valve useful in an oil filter

Info

Publication number: EP0902717A1
Application number: EP97925577A
Authority: EP
Inventors: Ronald F. Michalowski; Douglas R. Parnell; Thornton A. Pratt; Mark A. Solheim; Steven C. Barth; Brian J. Franzene
Original assignee: Filtertek Inc
Current assignee: Filtertek Inc
Priority date: 1996-05-23
Filing date: 1997-05-23
Publication date: 1999-03-24
Also published as: TW358846B; WO1997044113A1; AU3067497A

Abstract

An assembly includes at least one inlet port (36), at least one normal outlet port (31), at least one bypass port (30) and a safety relief valve system for regulating fluid flow from the inlet port to the bypass port. The valve system includes a compressible component (112) disposed adjacent to the bypass port. The valve system has a closed position wherein the compressible component prevents fluid flow through the bypass port. The valve system further includes an open position wherein the compressible component allows fluid flow through the bypass port when the inlet port is pressurized and the pressure differential between the inlet port and the normal outlet port is greater than or equal to a predetermined value. The assembly can be a fluid filter assembly. The present invention is also directed to a method for regulating fluid flow in an assembly by providing the previously described safety relief valve system and introducing fluid into the assembly.

Description

SAFETY RELIEF VALVE USEFUL IN AN OIL FILTER

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation- in-part of application serial no. 08/712,130 filed September 11 , 1996, which is a continuation-in-part of application serial no. 08/652,226 filed May 23, 1996, both of which are hereby incoφorated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a safety relief valve system. More particularly, the present invention relates to a pressure relief valve system that is useful in an fluid filter assembly to be used, for example, to filter lubricating oil of an internal combustion engine.

A spin-on, throw-away type of fluid filter is commonly used as an oil filter for motor vehicles because it is relatively inexpensive to mass produce and easy to install and replace. A spin-on, throw-away filter usually has, among other things, a filter housing with an open end partially covered by a mounted plate having a plurality of inlet pores to allow oil to flow from the motor to the inside of the filter and a central aperture usually threaded for spin-on mounting to the motor and transmitting oil from the inside of the filter back to the motor, a closed or domed end, at least one filter element contained in the filter housing, a center tube extending longitudinally at the interior of the filter element, and a relief valve having open and closed positions in case the filter element becomes plugged.

Under normal operating conditions, oil flows from the motor, through the inlet pores of the mounting plate, through the filter element, out the threaded central aperture and back to the engine. Under bypass operating capacity or high pressure surges occur, such as in cold starts of the motor, the relief valve is caused to open and immediately returns oil to the motor to assure that sufficient oil reaches the motor parts requiring lubrication, thus bypassing the filter element. Thus, the engine is supplied with at least unfiltered lubricant rather than either no lubricant at all or insufficient lubricant.

Conventional safety relief valves commonly contain a compression spring made of a metallic material for biasing a seal that closes the relief valve under normal operating conditions. Under bypass operating conditions, the spring is compressed by the high pressure differential between the inlet and the outlet. As with virtually any component made of a metallic material, such a conventional spring is subject to corrosion and fatigue that shortens its functional lifespan. In addition, metal components are not readily recyclable and thus can pose environmental concerns. Furthermore, conventional safety relief valves also commonly employ numerous components, which increase production and assembly costs.

SUMMARY OF THE INVENTION

The present invention provides an assembly that employs a safety relief valve system. More specifically, the present invention relates to a filter assembly including assembly component including at least one inlet port, a second assembly component including at least one normal outlet port, a third assembly component including at least one bypass port and further includes a safety relief valve system that controls fluid flow through the bypass port with a compressible component. The safety relief valve has a closed position in which the compressible component prevents fluid flow through the bypass port, and an open position in which the compressible component responds to a predetermined pressure differential between the inlet port and the normal outlet port and thereby allows fluid flow through at least a portion of at least one of the bypass port(s). In a preferred embodiment, the compressible component comprises a nonmetallic material.

In a first embodiment of the invention, the compressible component includes a series of O-rings. In addition, the safety relief valve system of the first embodiment includes a valve body, a valve body cap adjoined to the valve body having at least one cap opening for receiving fluid flow from the inlet port, a seal ring disposed within the valve body and adjacent to the valve body cap, the seal ring having a first face adjacent to the cap opening and an opposite second face adjacent to the compressible component, such that the first face of the seal ring and the cap opening define a flow path for fluid flow between the inlet port and the bypass port when the valve is in its open position. In a second embodiment of the invention, the compressible component has a bellow-shaped configuration. Additionally, the safety relief valve system of the second embodiment includes the valve body and valve body cap as well as the seal ring of the first embodiment. In a third embodiment of the present invention, the compressible component includes a sleeve portion. In a fourth embodiment of the safety relief valve system, the compressible component includes at least one reed portion adjoined to a sleeve portion. The safety relief valve system such as the previously described third and fourth embodiments contains fewer components than the conventional valve systems. The compressible component of the third and fourth embodiments may include a metallic material. In a fifth embodiment of the present invention, the compressible component includes a helix portion.

The present invention is also directed to a fluid filter assembly containing the pressure relief valve system of the present invention. In one embodiment of the invention, the filter assembly includes a housing having a first end, a second opposite end, an first end member adjoined to the first end and including a central outlet and at least one inlet port disposed around the central outlet, a second end member adjoined to the second end, an outlet tube adjoined to the first end member and connected to the central outlet, the outlet tube including at least one bypass port adjacent to first end and a normal outlet port adjacent to the second end. Preferably, the filter housing is made of a plastic mateπal. In one preferred embodiment of the present invention, the second and third assembly components are the same and is a centrally disposed tube. In another preferred embodiment of the present invention, the second assembly component is a centrally disposed outlet tube and the third assembly component is a valve body that also houses the compressible component.

In a fluid filter assembly of the present invention employing the first and second embodiments of the safety relief valve system, the valve body surrounds the outer tubing wall of the outlet tube adjacent the bypass port. In a preferred embodiment, the fluid filter assembly employs the safety relief valve system of the third embodiment wherein a sleeve portion surrounds the outer tubing wall of the outlet tube. In a more preferred embodiment, the fluid filter assembly employs a safety relief valve system of the fourth embodiment wherein the sleeve portion with at least one reed portion is disposed about the interior tubing wall of the outlet tube. In an even more preferred embodiment, the fluid filter assembly employs a safety relief valve system of the fifth embodiment wherein the compressible component including a helix portion is housed in a valve body that also includes at least one bypass port.

The present invention is further directed to a method of regulating fluid flow in an assembly by providing the previously described safety relief valve system.

It should be understood that the safety relief valve system of the present invention may be adapted to be employed in any assemblies that conventionally contains pressure relief valve feature.

These and other advantages and features of the present invention will be better understood upon review of the following detailed description of various of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an oil filter equipped with a first embodiment of the safety relief valve system of the present invention.

FIG. 2 is a close-up view of FIG. 1 showing the safety relief valve system in its "bypass" position.

FIG. 3 is a perspective view of a second embodiment of the safety relief valve system of the present invention. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3 showing the valve system in its "closed" position.

FIG. 5 is a cross-sectional view taken along line 4-4 of FIG. 3 showing the valve system in its "bypass" position.

FIG. 6 is a perspective view of a third embodiment of the safety relief valve system of the present invention.

FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. 6 showing the valve system in its "closed" position.

FIG. 8 is a cross-sectional view of taken along line 7-7 of FIG. 6 showing the valve system in its "bypass" position.

FIG. 9 is a perspective view of a fourth embodiment of the safety relief valve system of the present invention.

FIG. 10 is a cross-sectional view taken along line 10- 10 of FIG. 9 showing the valve system in its "closed" position.

FIG. 1 1 is a cross-sectional view taken along line 10-10 of FIG. 9 showing the valve system in its "bypass" position.

FIG. 12 is a perspective view of a fifth embodiment of the safety relief valve system of the present invention.

FIG. 13 is a cross-sectional view taken along line 13- 13 of FIG. 12 showing the valve system in its "closed" position.

FIG. 14 is a cross-sectional view taken along line 14- 14 of FIG. 12 showing the valve system in its "bypass" position.

FIG. 15 is an end plan view of a second oil filter assembly equipped with the unique features of a sixth embodiment of the present invention.

FIG. 16 is a cross-sectional view taken along the line 16-16 of FIG. 15.

FIG. 17 is a side elevational view of a third oil filter assembly equipped with a seventh embodiment of the safety relief valve system of the present invention.

FIG. 18 is an exploded elevational view of selected components of the oil filter assembly shown in FIG. 17. FIG. 19 is a close-up perspective view of the valve body and bypass ports of the seventh embodiment of the safety relief valve system shown in FIGS. 17 and 18.

FIG. 20 is a close-up perspective view of the compressible component of the seventh embodiment of the safety relief valve system shown in FIG. 17.

FIG. 21 is an inverted, exploded perspective view of selected components of the oil filter assembly shown in FIG. 17.

FIG. 22 is a side elevatoinal view of a mold for the compressible component of FIG. 20.

DETAILED DESCRIPTION OF THE DRAWINGS AND PREFERRED EMBODIMENTS

For illustration purposes, the first embodiment of the safely relief valve system of the present invention is shown in an oil filter assembly 10. Other details of the oil filter assembly 10 are shown in U.S. application serial no. 08/799,657 titled "Fluid Filter," filed February 1 1, 1997 and U.S. application serial no. 08/712,122 titled "Filtration Element And Method of Making The Same," filed September 1 1 , 1996, and parent applications of these applications, namely serial nos. 08/714,021 , 08/652,291 and 08/652,771 , all of which are hereby incorporated by reference.

The oil filter assembly 10 is contained in a cylindrical housing or container 12 with a central axis 14. The housing 12 has a first end 16 and a second opposite end 18. The housing is made up of a first end member 26 adjoined to the first end 16, a sidewall 24 and a second end member or base 20 adjoined to the second end 18. As shown in FIG. 1 , the oil filter assembly 10 contains a first passageway 28 centrally disposed about the central axis 14. Essentially the entire portion of the first passageway 28 is defined by a central tubing. The central tubing 28 has a central axis that is coincident with that of the housing 12. In the illustrated embodiment, the first passageway is the outlet for fluid flow out of the housing 12. The illustrated central tubing is thus an outlet tube. The illustrated outlet tube includes a tubing exterior end or central outlet 29 defined by the first end member 26, a tubing interior end or normal outlet port 31 , which is adjacent to the second end 18 and at least one bypass port 30 between central outlet 29, and normal outlet port 31. The outlet tube has an outer tubing wall 32 and an inner tubing wall 33. The housing and other internal components are preferably made of recyclable plastic materials.

The assembly 10 further contains a plurality of second passageways 34 that are generally parallel to the first passageway 28 and are circumferentially spaced relative to the first passageway 28. In the illustrated embodiment, the second passageways are the inlet for fluid flow into the housing 12. An anti- drain back valve 37 is disposed adjacent to inlet ports 36 and held in place by a retainer ring 38. The second passageways begin at inlet ports 36, which are defined by the first end member 26. The filter assembly 10 of FIG. 1 also contains a coarse filtration element 70 and a fine filtration element 100 placed in series relative to each other and concentrically disposed about the outlet tube 28. The fine filtration element 100 is supported by element support 102. A permanently open fine filter bypass path 104 is disposed parallel to the fine filter element 100.

The assembly 10 also contains a pressure relief valve assembly 1 10 adjacent the bypass port 30 and configured to be disposed in the second passageway between the inlet ports 36 and the coarse filtration element 70. Under normal operating conditions, oil enters the filter assembly 10 tlirough the eight inlet ports 36. From there the oil travels through coarse filtration element 70, and partially tlirough fine filtration element 100. Oil is directed by a plurality of channel ribs 40 adjacent to the closed end 18 of the cylindrical housing 12 towards the normal outlet port or tubing interior end 31 and thereafter exits the filter assembly 10 from the central outlet or tubing exterior end 29. Under bypass operating conditions, the relief valve system 1 10 is configured into an open position such that oil from the inlet ports 36 flows tlirough cap opening 134 to the bypass port 30, into outlet tube 28 and immediately returns to the engine.

The compressible component of the present invention can comprise of any material that is flexible and is capable of providing an adequate seal against the bypass port 30. Suitable materials may be, for example, metallic. nonmetallic or a combination thereof. Preferably, the compressible component comprises nonmetallic materials. The specific choice of material as well as the dimensions of the compressible component depend upon the desired resistance value of the compressible component.

The term "resistance value" is used to denote a physical characteristic, expressed in units such as pounds per square inch (p.s.i.), of the compressible component at the operating temperature of the filter assembly. The resistance value is generally defined as the necessary amount of stress placed upon a material to induce elastic deformation of that material. Upon removal of this stress, the material returns to its original dimension.

The thickness and the composition of the compressible component should be coordinated so that the compressible component is rigid to fluid flow below a pre-set limit of back-pressure in the fluid filter assembly and is compressed in response to a pressure differential that is at or above the pre-set limit. Thus, a suitable compressible component material has a resistance value that substantially corresponds to or is equal to a predetermined pressure differential value, so that when the operating pressure differential is beiow the predetermined value, the compressible component prevents fluid flow through the bypass port, and when the operating pressure differential reaches or exceeds the predetermined value, the compressible component allows fluid flow through the bypass port. For example, the safety relief valve open or bypass position in a lubricating oil filter assembly typically requires a pressure differential of about 12±3 psig.

In addition, the material should also be essentially chemically nonreactive with the fluid being filtered by the fluid filter assembly containing the safety relief valve system of the present invention. Examples of suitable types of nonmetallic materials include thermoset rubbers, thermoplastics and thermoplastic elastomers.

When the safety relief valve system is employed in an oil filter assembly, the compressible component preferably comprises a thermoset rubber or a thermoplastic elastomer. More preferably, the compressible component comprises a thermoplastic elastomeric material. In general, a thermoplastic elastomer (TPE) is a rubbery material that can be processed in the molten state as a thermoplastic and that has many of the performance characteristics of thermoset rubber. TPE has elastic properties such as flexibility, ease of distortion under a predetermined applied load, and recovery of most of its original shape after removal of an externally applied stress. TPE types that are suitable for the present invention include, for example, polymer blends such as thermoplastic olefinic blends, which contains a ethylene-propylene teφolymer (EPDM) with polypropylene (PP) or polyethylene (PE), and blends of nitril rubber (NBR) and polyvinylchloride (PVC); two-phase materials known as elastomeric alloys that contain, for example, EPDM, NBR or natural rubber (NR) as the soft phase and a polyolefin such as PP as the hard phase; block copolymer TPE containing both hard and soft segments along a common polymer chain that include, for example, polymers of styrene and dienes (known as styrenics), copolyesters (COPs), polyurethanes and polyamides. Specific examples of suitable TPEs can be found in Harper, Handbook of Plastics, Elastomers, and Composites (McGraw-Hill 2nd Ed. 1992), the relevant portions of which are incorporated herein by reference.

The components of the preferred safety relief valve system of the present invention can be formed using any processes suitable for processing the material. Suitable processes for nonmetallic materials include, for example, injection molding, machine tool processing, extrusion and compression molding.

The drawings illustrate six embodiments of the safety relief valve system of the present invention. Referring now to FIG. 1 and 2 for the first embodiment of the present invention, the safety relief valve system 1 10 is housed in a valve body 1 14 that covers the bypass port 30 by surrounding the outlet tube 28. The valve body 1 14 has an open end 1 16 defined by a first valve body portion 120 and an opposite support end 1 18 defined by a second valve body portion 1 12. The second valve body portion 1 12 is adjacent to the element support 102 of the fine filtration element 100. The valve body 1 14 further includes a support base 124 at the support end 1 18. A valve body cap 132 is adjoined with the open end 1 16 of the valve body 1 14. The valve body cap 132 defines four cap openings 134 for receiving flow of oil from the inlet ports 36. In the illustrated first embodiment, a compressible component 1 12 is disposed within the valve body 114 and adjacent to the bypass ports 30 wherein the compressible component 112 is supported by the support base 124 at the support end 118 of the valve body 1 14. The compressible component 1 12 includes a series of five O-rings 126 vertically disposed relative to each other. A seal ring 136 is also disposed within the valve body 1 14 and adjacent to the valve body cap 132. The seal ring 136 includes a first face 138 that is adjacent to the cap openings 134 and an opposite second face 140 that is adjacent to a compressible component 112.

Under normal operations of the filter assembly 10, the first embodiment of the safety relief valve of the present invention remains in its "closed position" as shown in FIG. 1. More specifically, the O-rings 126 making up the compressible component 1 12 are in their relaxed state and resist against oil flowing into the valve body 1 14 through the cap openings 134, and thereby close off the bypass ports 30 as well as press against the seal. Oil thus flows through filtration element 70 and partly through filtration element 100, and thereafter into the central tube 28 through the normal outlet port 31. When the pressure differential between the inlet ports 36 and the normal outlet ports 31 reaches or exceeds a predetermined value, the safety relief valve changes to its bypass position as shown in FIG. 2. More specifically, the O-rings 126 making up the compressible component 1 12 are compressed in a downward direction that is parallel to the central axis 14, thereby uncovering at least a portion of at least one of the bypass ports 30. As shown by the arrows in FIG. 2, oil flows from inlet ports 36 past the antidrain-back valve 37 and along a flow path defined by cap openings 134 and the first face 138 of seal ring 136 to the bypass ports 30 and thereby exiting the filter assembly 10 without flowing through filtration elements 70, 100.

In the embodiment shown in FIGS. 1 and 2, the valve body 1 14 consists of two portions 120, 122 wherein the second portion 122 as well as support base 124 attached thereto are pre-molded with element support 102. This optional design provides manufacturing flexibility because it allows the use of one element support configuration in filter assemblies of the present invention regardless of which embodiment of the safety relief valve system is used. This advantage is further discussed below in connection with FIG. 6.

The valve body 1 14 and the valve body cap 132 comprise a substantially rigid thermoplastic material suitable for housing components. For example, the valve body 128 and valve body cap 132 may comprise a suitable grade of a nylon material such as, for example, Nylon 6 or Nylon 6/6 G.F. (where G.F. denotes "glass-filled") available from Texapol, Inc. of Bethlehem, PA. Portions of the valve body 120, 122 and the valve body cap 132 can be pre-formed by any suitable process such as, for example, injection molding. Portions 120, 122 of the valve body can be adjoined using suitable fusion processes such as, for example, ultrasonic welding, gluing, electromagnetic bonding, induction bonding, hot-plate welding, insert bonding, spin welding, thermostaking, vibration welding, injection molding and others. Portions 120, 122 are preferably adjoined by ultra-sonic welding.

The O-rings 126 making up the compressible component 1 12 comprise a non-metallic material as described hereinabove. In this first embodiment, the O-rings 126 preferably comprise a thermoplastic elastomeric material such as a block copolymer TPE. More preferably, the O-rings 126 making up the compressible component 1 12 comprise polyurethane TPE such as, for example, rubber "O-Rings," product number N2624, having a durometer rating of 70A±5. manufactured by Goshen Rubber, Inc. of Goshen, Indiana. The seal ring 136 also comprises nonmetallic material that is capable of providing a seal effect to prevent leakage when the seal ring 136 rests against the valve body cap 132 in the valve's "closed" position. In this first embodiment, the seal ring 120 is preferably obtained using extrusion.

Preferably, safety relief valve system 1 12 is assembled in the following manner. The valve body 122 is held in a vertical position. The O-rings 126 in a stacked vertical position are inserted into the valve body 122 and allowed to drop to the support base 124. The cap 120 with the seal ring 136 inserted therein is placed over the O-rings 126, then compressed to a closed position. The assembly is then ultra-sonically welded together. FIGS. 3-5 illustrate a second embodiment of the safety relief valve system of the present invention. As shown in these figures, the safety relief valve system 150 includes a valve body 128, a valve body cap 132 and a seal ring 136 as in the safety relief valve 110 of the first embodiment. The O-rings 126 of the first embodiment is replaced with a compressible component 152 having a bellowed-shape configuration.

Under normal operations of the filter assembly 10, the second embodiment of the safety relief valve of the present invention remains in its "closed position" as shown in FIG. 4. More specifically, the bellow-shaped compressible component 152 is in its relaxed state and resists against oil flowing into the valve body 114 through the cap openings 134, and thereby closes off the bypass ports 30a as well as biases against the seal. Oil thus flows through filtration element 70 and partly through filtration clement 100, and thereafter into the central tube 28 through the normal outlet port 31. When the pressure differential between the inlet ports 36 and the normal outlet ports 31 reaches or exceeds a predetermined value, the safety relief valve 150 changes to its bypass position as shown in FIG. 5. More specifically, the bellow-shaped compressible component 152 is compressed in a downward direction that is parallel to the central axis 14, thereby uncovering at least a portion of at least one of the bypass ports 30. As shown by the arrows in FIG. 5, oil flows from inlet ports of the filter assembly along a flow path defined by cap openings 134 and the first face 138 of seal ring 136 to the bypass ports 30a and thereby exiting the filter assembly 10 without flowing through filtration elements 70, 100.

The bellow-shaped compressible component 152 preferably comprises a thermoplastic elastomeric material such as a block copolymer TPE. Preferably, the compressible component 152 is made of a material comprising a suitable grade of nylon material with additives, such as, for example, Nylon 6/6 G.F. available from Texapol, Inc. of Bethlehem, PA. The preferred additives include glass fibers or spheres. The amount of fillers used depends upon the required resistance value of the compressible component. Up to about 45% of additive can be incorporated. Preferably, the compressible component 152 includes from about 5 to about 20% glass fiber.

Preferably, the seal ring 120 and the compressible component 152 are formed using injection molding. The safety relief valve system 150 can be assembled in the same manner as the safety relief valve system 110 of the first embodiment.

FIGS. 6-8 illustrate a third embodiment of the present invention. As shown in FIG. 6, safety relief valve system 160 includes a compressible component 162 disposed circumferentially outside of the outlet tube 28. The compressible component 162 includes a sleeve portion 164 and at least one reed portion 166 that is integral to the sleeve portion. The reed portion 166 is configured to be able to substantially cover an outlet bypass port 30a when the filter assembly 10 is operating under normal conditions, as shown in FIG. 7, and to flex into outlet bypass port 30a in response to a pressure differential that is greater than or equal to a pre-set limit, as shown in FIG. 8. Safety relief valve 160 having the illustrated configuration can also be employed in a fluid filter assembly having fluid flow in a direction opposite of those in illustrated embodiments, wherein, for example, the central tube 28 of FIG. 1 is an inlet and ports 36 of FIG. 1 are outlets. As shown in FIG. 6, this third embodiment does not employ a valve housing as was necessary in the first two embodiments shown in FIGS. 1-5. Nevertheless, the same element support 102 can be used because the valve body for the first two embodiments is formed in two portions 120. 122 shown in FIGS. 1-5.

A preferred material for the compressible component 162 is a thermoplastic elastomer (TPE) that can be processed to a defined shape and resistance value for each desired application. Preferably, the compressible component is made of a material including a TPE and up to about 45% of additive. Preferably, the TPE material is a suitable grade of nylon with from about 5% to about 20%, more preferably about 8% glass fiber.

FIGS. 9-1 1 illustrate a fourth embodiment of the safety relief valve system of the present invention. In this embodiment, the safety relief valve 170 includes a compressible component 172 with a sleeve or tube configuration. Compressible component 172 is disposed inside outlet tube 28 adjacent to the bypass ports 30a. The inner tubing wall 33 may be provided with a ridge (not shown) to help keep the compressible component 172 in place. In the closed position of the safety relief valve 170, shown in FIG. 10, the compressible component 172 rests against the inner tubing wall 33 and thereby covers the outlet bypass ports 30a so that the fluid flow path does not include the bypass ports 30a. In the bypass position of the safety relief valve 170, as shown in FIG. 1 1 , fluid flow (represented by the arrows) compresses compressible component 172 inward in a direction essentially peφendicular to the central axis 14, so that an amount of unfiltered oil is diverted out of the filter assembly 10. Preferably, the compressible component 172 may be formed by suitable processes such as, for example, extrusion or lace cut.

A preferred material for compressible component 172 may be the same as the material for compressible component 162 described above.

FIGS. 12-14 illustrate a fifth embodiment of the safety relief valve system of the present invention. In this embodiment, the safety relief valve 180 includes a compressible component 182 disposed inside outlet tube 28a, similar to the disposition of the compressible component 172 used in the fourth embodiment described above. Compressible component 182 includes a sleeve portion 184 and a reed portion 186. In the closed position of the safety relief valve 180, shown in FIG. 13, the compressible component 182 rests against the inner tubing wall 33 such that each reed portion 186 covers a corresponding outlet bypass port 30a. Thus, the fluid flow path does not include the bypass ports 30a. In the bypass position of the safety relief valve 180, as shown in FIG. 14, fluid flow (represented by the arrows) compresses reed portions 186 inward in a direction essentially perpendicular to the central axis 14, so that an amount of unfiltered oil is diverted out of the filter assembly 10. A preferred material for the compressible component 182 is a nylon material such as Nylon 6 or Nylon 6/6. Preferably, the compressible component is made of a material including a TPE and up to about 45% of additive. Preferably, the TPE material is a suitable grade of nylon with from about 5% to about 20%, more preferably about 6% glass fiber. In the illustrated third and fifth embodiments, the sleeve portion 164, 184 is provided below the bypass ports 30a. However, it should be understood that the sleeve portion may also be provided above the bypass ports such that the reed portions covering the outlet bypass ports are correspondingly below the sleeve portion.

It should be understood that the bypass port can be of any shape and that the outlet tube may contain any number of bypass ports, so long as the compressible component of the present invention substantially covers the bypass port when the safety relief valve system is in its closed position. In the illustrated embodiments, FIGS. 1 and 2 show an outlet tube 28 that defines four bypass ports 30 having a vertically oval configuration. FIGS. 3-14 show bypass ports 30a having a horizontally oval configuration. In addition, while the outlet tube 28 in FIGS. 3-1 1 defines four bypass ports 30a, the outlet tube 28a shown in FIGS. 12-14 defines two bypass ports 30a. It should be understood that the number and shape of the bypass ports can be varied. Preferably, the combined area of the bypass ports allows the same volume of or more liquid to pass through the openings as is allowed in through the inlet ports in the first end member.

With regards to all components of the assembly that can be made of a material comprising a thermoplastic material or thermoplastic elastomeric material, it should be understood that the material may be reinforced to contain additives or combinations of additives such as, for example, fillers containing mineral, glass or combinations thereof, as well as fibers containing aramids, carbon, ceramics, glass, thermoplastics or combinations thereof.

FIGS. 15 and 16 illustrate a second preferred oil filter assembly 300. Other details of the oil filter assembly 300 are shown in two other applications being filed concurrently, namely. "Fluid Filter Containing Ribbed Flow Channels And Integral Tube," attorney docket no. 396/139 and "Filtration Element And Method of Making The Same," attorney docket no. 396/140. and parent applications of these applications, namely serial nos. 08/652,291 and 08/652,771, all of which are hereby incorporated by reference. The filter assembly 300 comprises an interior chamber 310 enclosed by a filter housing 320. The filter housing 320 has a cylindrical side wall 322 that connects a first end member 324 to an opposing second end member 326. The second end member 326 includes a plurality of channel ribs 328. In the preferred embodiment shown, the thickness of the side wall 322 increases near the first end member 324 of the housing 320.

As best seen in FIG. 16, the first end member 324 of the filter housing comprises rim 330 having an exterior surface 332 and an interior surface 334. The rim 330 of the first end member 324 is bonded to the edge of the filter housing side wall 322. In the embodiment illustrated, a tongue and groove joint 336 forms the connection between the rim interior surface 334 and the side wall 322. As best seen in FIG. 15, the rim exterior surface 332 comprises a continuous slot 338. The slot 338 is configured to accommodate a seal or gasket (not shown).

The first end member 324 further comprises a centrally disposed first passageway 340. The first passageway 340 is defined by an outlet tube 342 having an exterior end 344 and an interior end 346. The outlet tube exterior end 344 is positioned approximately even with the plane of the rim exterior surface 332. The outlet tube interior end 342 near the channel ribs 328.

The first end member 324 further comprises a flange member 350 which projects outwardly from the outlet tube 342 and terminates at the rim 330. In the preferred embodiment shown, the flange member 350 has a conical shape. As best seen in FIG. 16, the juncture of the flange member 350 and the outlet tube 342 is angularly disposed and inward of the outlet tube exterior end 344. The conical shape of the flange member 350 and the configuration of the juncture to the outlet tube 342 increases the strength of the first end member 324 and reduces the possibility of structural deformation of the container that may be caused by stresses from hydrostatic pressure.

A recessed inlet area 352 is formed exterior to the flange 350 between the outlet tube 342 and the rim 330. The function of the inlet area 352 is to collect and distribute inlet fluid. A plurality of flange ribs 354 connect the exterior surface of the flange member 350 to outlet tube 342. The exterior edges of the flange ribs 354 are disposed inward of the plane of the rim exterior surface 332 to allow fluid to flow throughout the inlet area 352. The flange ribs 354 provide additional support and rigidity for the connection of the flange member 350 to the outlet tube 342.

In an alternative embodiment (not shown), the flange ribs 354 are connected between the interior surface of the flange member 350 and the outlet tube 342. The location of the flange ribs 354 on the inside of the filter housing 320 prevents the flange ribs 354 from interfering with the flow of fluid throughout the inlet area 352.

The flange member 350 comprises a plurality of inlet ports 356 that are circumferentially spaced relative to the first passageway 340 and between the flange ribs 354. The inlet ports 356 provide a fluid communication between the inlet area 352 and the second passageway 358 of the filter assembly 300. An anti-drain back valve 360 is disposed adjacent to the inlet ports 356 and held in place by a retainer ring 362. In another embodiment (not shown), the anti-drain back valve can be held in place by another component of the assembly, such as, for example, a portion of a filtration element.

In the embodiment illustrated, the rim 330, flange member 350, flange ribs 354, and outlet tube 342 are manufactured as a monolithic component, preferably by injection molding.

The filter assembly 300 also contains a coarse filtration element 500 and a fine filtration element 510 placed in series relative to each other and concentrically disposed about the outlet tube 342. The fine filtration element 510 is supported by element support 512. A permanently open fine filter bypass path 514 is disposed parallel to the fine filtration element 510.

The assembly 300 also contains a pressure relief valve 610 adjacent to at least one bypass port 348, which is defined by the outlet tube 342. The bypass port 348 is configured to be disposed between the inlet ports 342 and the coarse filtration element 500. As illustrated in FIG. 16, the safety relief valve 610 is disposed inside the outlet tube 342. Under normal operating conditions, oil enters the filter assembly 300 from the eight inlet ports 342. From there the oil travels through coarse filtration element 500, and partially through fine filtration element 510. Oil is directed by a plurality of chaimel ribs, which are connected to the second end member 320. Under bypass operating conditions the relief valve 610 is configured into an open position such that oil from the inlet ports 342 flows through bypass ports 348, into outlet tube 342 and immediately returns to the engine.

FIGS. 17-21 illustrate a third preferred oil filter assembly 700. As best seen in FIG. 17, the filter assembly 700 comprises an interior chamber 710 enclosed by a filter housing 720. This embodiment uses the same housing as the embodiment illustrated in FIGS. 15 and 16, so that it could be made in the same mold. The filter housing 720 has a cylindrical side wall 722 that connects a first end member 724 to an opposite second end member 726. As best seen in FIGS. 17, 18 and 21, the first end member 724 has an interior surface 723 and an opposite exterior surface 725. The first end member 724 includes a rim 730 having a rim exterior surface 732 and a opposite rim interior surface 734. The rim 730 of the first end member 724 is bonded to the edge of the filter housing side wall 722. As best seen in FIGS. 17 and 18, a tongue and groove joint 736, having a tongue portion 736a and a groove portion 736b, forms the connection between the rim interior surface 734 and the side wall 722. As best seen in FIG. 18, the rim exterior surface 732 includes a continuous slot 738. The slot 738 is configured to accommodate a seal or gasket 739 (as best seen in FIGS. 17, 18 and 21). As best seen in FIG. 21 , the first member 724 also includes a flange member 750 similar to the flange member 350 shown in FIGS. 15-16. As best seen in FIGS. 17 and 18, the second end member 726 includes a plurality of channel ribs 728. In the preferred embodiment shown, the thickness of the side wall 722 increases near the first end member 724 of the housing 720.

As best seen in FIGS. 17, 18 and 21, the filtration element 770 includes a vertically pleated filtration media 780 supported by a filtration media center support tube 782 and a first 784 and a second 786 media end caps. The filtration media center support tube 782 includes openings 783 that allow fluid communication between the filtration media 780 and the center tube 742. Each media end cap 784, 786 includes a first support rim 788 and a second support rim 790 to further retain the structural integrity of the filtration media 780. Filtration media 780 can be a synthetic or nonsynthetic, woven or nonwoven media. The media end caps 784, 786 are annular in shape to allow fluid communication between the outlet tube 742 (further described below) and the media center support tube 782. As best seen in FIG. 17, the second media end cap 786 rests upon the channel ribs 728. Thus, the channel ribs 728 in this embodiment also support the filtration element 770. The terminal ends of the filtration media 780 is adjoined to the first 784, and second 786 media end caps with, for example, epoxy. The filtration media center support tube 782 is preferably adjoined to the end caps 784, 786, using a suitable fusion process such as, for example, ultrasonic welding, gluing, electromagnetic bonding, induction bonding, hot-plate welding, insert bonding, spin welding, thermostating, vibration welding, injection molding and others.

As best seen in FIG. 19, a valve body 810 is adjoined to the second media end cap 786. This valve body 810 is part of the pressure relief valve system 800 (described below), as best seen in FIGS. 17 and 18. The second media end cap 786, the support rims 788, 790 and the valve body 810 are preferably pre-formed by any suitable process such as, for example, injection molding. Thus, the preferred material for the valve body 810, support rims 788, 790 and second media end cap 786 is a nonmetallic material such as, for example, a suitable grade of a nylon material.

The first end member 724 further comprises a centrally disposed first passageway 740. The first passageway 740 is partially defined by an outlet tube 742 having an exterior end 744 and an interior end 746. The outlet tube exterior end 744 is positioned approximately even with the plane of the rim exterior surface 732. The outlet tube terminates at the outlet tube interior end 746 near the filtration media center support tube 782, which defines the remaining first passageway 740 and terminates near the channel ribs 728.

As best seen in FIGS. 17 and 18, the flange member 750 comprises a plurality of inlet ports 756 that are circumferentially spaced relative to the first passageway 740 and between the flange ribs 754. The inlet ports 756 allow fluid communication between the inlet area 752 and the second passageway 758 of the filter assembly 700. As best seen in FIGS. 17 and 21 , an anti-drain back valve 760 is disposed adjacent to the inlet ports 756 and held in place by a retainer ring 762. In another embodiment (not shown), the anti-drain back valve can be held in place by another component of the assembly, such as, for example, a portion of a filtration element. As best seen in FIG. 17, a substantial portion of the second passageway 758 is defined by the outer circumference of the filter element 770 and the interior surface of the side wall 722.

As best seen in FIG. 17, the safety relief valve system 800 is disposed within the filtration media center support tube 782. The safety relief valve system 800 includes the valve body 810 and a compressible component 802. As best seen in FIGS. 17-19, the valve body 810 includes a first open end 814, an opposite second body end 816, and four bypass ports 812 adjacent to the second body end 816. As indicated above, the valve body 810 houses the compressible component 802. As best seen in FIGS. 17, 18 and 20, the compressible component 802 includes a compressible portion 804 having a helical configuration ("helical portion") and a plug portion 805, with a first support end 807 adjacent to the plug portion 805 and a second support end 809 opposite the first support end 807. The plug portion 805 includes a recess 806 dimensioned to accommodate a seal ring 808. In the illustrated embodiment, the seal ring 808 is an O-ring.

The compressible component 802 can be made by, for example, injection molding. One useful example of a material for the compressible component 802 is a thermoplastic elastomer such as a nylon material. The desired resistance value required for a particular application can be obtained by, for example, adjusting the amount of addives mixed into the material making up the compressible component 802, adjusting the helical angle of the compressible portion 804, adjusting the dimensions of the material in the compressible portion 804. As best seen in FIG. 17, the seal ring 800 and the first support end 807 prevents oil from flowing through the bypass ports 812 when the valve system 800 is in the closed position (i.e., when the helix portion 804 is in a relaxed state). When the valve system 800 is in the open position (not shown) the helix portion 804 compresses so that the first support end 807 biases toward the second support end and the seal ring 800 is pushed to the point where oil can flow past the seal ring 800 and through the bypass ports 812. Oil then flows through the center support tube 782 to the normal outlet 742.

Under normal operating conditions, oil enters the filter assembly 700 from eight inlet ports 756. From there the oil from the second passageway 758 travels through filtration element 770. Oil is directed to the center support tube 782 and flows through both the center support tube 782 and the outlet tube 742 and returns to the engine.

Under bypass operating conditions, oil from the second passageway is directed by the channel ribs 728 towards the first support end 807. The compressible component 802 is configured into an open position such that oil from the inlet ports 756 flows through bypass ports 812, through the filtration media center support tube 782, into outlet tube 742 and immediately returns to the engine.

It should be understood that valve body 810 may house a compressible component having a compressible portion (not shown) of another configuration. For example, the compressible portion may be bellow-shaped or may include a plurality of O-rings.

The example below further illustrates an embodiment of the present invention.

EXAMPLE

A compressible component such as component 802 as best seen in FIGS. 17, 18 and 20 was produced.

FIG. 22 illustrates a mold 900 used to form component 802. The mold 900 was made of a solid steel material, and includes a tray 902 affixed to a tray handle 904 by bolt 956. Bolts 954, 960 and 962 also affix portions of the tray 902. A locating bushing 948 is secured to the tray by bolt 964. A sleeve 906. dimensioned to receive a threaded insert 908, is mounted to the tray 902. The threaded insert 908 is made of a solid steel material and includes a threaded mold counterpart 910 to the helix portion 804 of the compressible component 802 illustrated in FIG. 20. The the mold counterpart 912 for the plug portion 805 of the compressible component 802 is provided by a first side-slide insert 940. A second side-slide insert 942 is designed to receive the threaded mold counteφart 910. A third side-slide insert 944 is designed to receive a portion of the threaded insert 908. A set of gibs 914 is affixed to the tray 902 by bolt 958.

The mold 900 further includes a runner block 950, secured to the mold 900 by screws 952. The runner block 950 includes a horizontal runner 926, a first vertical runner 927 and a second vertical runner 928. The second vertical runner 928 includes a gate 929, which is the entrance into the mold counterpart 912 for the plug portion 805. The horizontal runner 926 is about two inches long and has a trapezoidal cross-section with a dimension of about 3/16 inch in diameter + 7.5° per side. The vertical runners 927, 928 have a circular cross- section. Each vertical runner 927, 928 is about one inch long and has a diameter of about 1 /8 inch. The horizontal runner 926 meets a sprue 920 defined by a sprue bushing 922. A sprue puller 924 terminates the sprue 920 on one end, and an inlet opening 918 terminates the other end of the sprue 920. The sprue bushing 922 fits into a top platten 919 of a plastic injection molding machine (not shown). The sprue 920 has a circular cross-section and has a dimension of about 2.25 inches long and a 7/32 inch, diameter, with a 0.5 inch per foot taper in diameter as the sprue. A locating ring 916 is secured to the top platten 919 by bolt 917. The mold 900 further includes a three water lines 930, 932, 934 having water ports 931 , 933, 935, respectively.

To produce a compressible component, the mold 900 was mounted to a Injection Molding Machine (55-ton), available from Arburgh of Germany, at the locating ring 916.

The threaded insert 908 was thread-grounded with a thread grinding machine that is conventionally used to grind high-precision threads such as for making thread gauges. A suitable thread grinding machine is available from Thread And Gauge Company of Sprng Grove, Illinois, U.S.A.

The side-slide inserts 940, 942, 944 were installed into the mold 900. The tray 902 of the mold 900 was slide out of the mold 900, in direction 980. The threaded insert 908 was placed into the sleeve 906. The tray 902 was then slide into the mold. The mold 900 was then closed. The Plastic Injection Molding Machine injected into the inlet opening 918 a Nylon 6/6 (13% glass- filled) at the material's plasticize point (which is about 500°F). The injection pressure was about 1 ,200 pounds. The plastic material flows through the sprue 920, the runners 926, 927, 928 to reach the cavity containing the mold counteφarts 910, 912. Water was fed through the water ports 931, 932 and allowed to exit the mold through port 933, in order to cool the plastic as it flowed through the mold. The water feed rate is regulated to maintain the temperature of water exiting port 933 at a desired temperature of, for example, about 160°F.

After the cooling cycle was completed (cycle time was about 20 seconds), the mold was opened and the threaded insert with the molded part still attached was removed from the mold. The base 909 of the threaded insert was placed into a fixture such as a clamp to prevent the base from rotating during the removal process of the molded part. The molded part, i.e., the compressible portion, was then removed from the threaded insert with a unscrew action using a wrench.

Because all of the components of the safety relief valve system can be made of nonmetallic materials, the system can last longer than commercially available pressure relief valve assemblies that deteriorate due to metal corrosion and fatigue. From an ecological view, the plastic components may be recycled in a controlled manner. Moreover, the simplistic design of the safety relief valve system of the present invention lends itself to a more economic manufacturing and assembly process.

Of course, it should be understood that a wide range of changes and modifications can be made to the embodiments described above. It is therefore intended that the foregoing description illustrates rather than limits this invention, and that it is the following claims, including all equivalents, which define this invention.

Claims

WHAT IS CLAIMED IS:

1. An assembly comprising a first assembly component including at least one inlet port, a second assembly component including at least one normal outlet port, a third assembly component including at least one bypass port and a safety relief valve system for regulating fluid flow through said bypass port, said valve system comprising a compressible component disposed adjacent to said bypass port, said compressible component comprising a nonmetallic material, said valve system having a closed position wherein said compressible component prevents fluid flow through said bypass port, said valve system further having an open position wherein said compressible component allows fluid flow through said bypass port when said inlet port is pressurized and said pressure differential between said inlet port and said normal outlet port is greater than or equal to a predetermined value.

2. The assembly of claim 1 wherein: a) said second and third components are an outlet tube; and b) said compressible component includes a sleeve portion fitted to said outlet tube.

3. The assembly of claim 2 wherein said compressible component further includes at least one reed portion adjoined to said sleeve portion.

4. The assembly of claim 2 wherein said compressible component is fitted inside said central tubing.

5. The assembly of claim 1 wherein said valve system further comprises: a) a valve body covering said bypass port; b) a valve body cap adjoined with said valve body, said valve body cap defining at least one cap opening for receiving fluid flow from said inlet port; and c) a seal ring disposed within said valve body and adjacent to said valve body cap, said seal ring having a first face adjacent to said cap opening and an opposite second face adjacent to said compressible component; d) wherein said cap opening and said first face of said seal ring define a flow path for fluid flow between said inlet port to said bypass port when said valve system is in said open position.

6. The assembly of claim 1 wherein said compressible component comprises a plurality of O-rings vertically disposed in series relative each other.

7. The assembly of claim 1 wherein said compressible component has a bellow-shaped configuration.

8. The assembly of claim 1 wherein said compressible component includes a helical portion.

9. The assembly of claim 1 wherein said compressible component comprises a material selected from thermoset rubbers, thermoplastics and combinations thereof.

10. The assembly of claim 1 wherein said compressible component comprises a material selected from thermoplastic olefinic blends, elastomeric alloys, block copolymer thermoplastic elastomers and combinations thereof.

1 1. The assembly of claim 1 wherein said bypass port is defined a valve body that houses said compressible component.

12. The assembly of claim 1 wherein said compressible component allows fluid flow through said bypass port and thereafter through said normal outlet port when said valve system is in said open position.

13. A fluid filter assembly comprising: a) a housing having a first end and an opposite second end; b) a first end member adjoined to said first end, said first end member including a central outlet and at least one inlet port disposed around said central outlet; c) a second end member adjoined to said second end; d) an outlet tube adjoined to said central outlet, said outlet tube including a normal outlet port, said inlet port and said normal outlet port having a pressure differential therebetween during operation of said assembly; e) an assembly component including at least one bypass port; f) a pressure relief valve system including a compressible component adjacent to said bypass port, said compressible component comprising a nonmetallic material having a resistance value that substantially corresponds to a predetermined value of the pressure differential, said valve system having a closed position wherein said compressible component prevents fluid flow through said bypass port when the pressure differential is below the predetermined value, said valve system further having an open position wherein said compressible component allows fluid flow through said bypass port when the pressure differential is substantially equal to or greater than the predetermined value.

14. The assembly of claim 13 wherein said component including said bypass port is said outlet tube.

15. The assembly of claim 13 wherein said assembly component including said bypass port is a valve body that houses said compressible component.

16. The assembly of claim 15 wherein: said valve body includes a first open end and an opposite second body end; said compressible component includes a first support end adjacent to said first open end and an opposite second support end adjacent to said second body end; said valve system is in said open position when the pressure differential biases said first support end of said compressible component towards said second support end to allow fluid flow through at least a portion of at least one of said bypass port.

17. The assembly of claim 16 wherein: said outlet tube has an interior end adjacent to said central outlet and an opposite exterior end adjacent to said normal outlet port; and said second body end of said valve body is adjacent to said interior end, such that said normal outlet port receives fluid flow from at a portion of at least one bypass port when said valve system is in said open position.

18. The assembly of claim 15 further comprising: a) a filter element disposed said housing, said element including a filtration media adjoined to a first end cap adjacent to said outlet tube, a second end cap opposite said first end cap; b) wherein said second end cap is adjoined to said valve body.

19. The assembly of claim 13 wherein said compressible component includes a sleeve portion.

20. The assembly of claim 15 wherein said compressible component is disposed circumferentially outside said outlet tube.

21. The assembly of claim 19 wherein said compressible component further includes at least one reed portion adjoined to said sleeve portion.

22. The assembly of claim 15 wherein said compressible component is disposed circumferentially inside said outlet tube.

23. The assembly of claim 22 wherein said compressible component further includes at least one reed portion adjoined to said sleeve portion.

24. The assembly of claim 14 wherein said valve assembly further comprises: a) a valve body covering said bypass port; b) a valve body cap adjoined with said valve body, said valve body cap defining at least one cap opening for receiving fluid flow from said inlet port; and c) a seal ring disposed within said valve body and adjacent to said valve body cap, said seal ring having a first face adjacent to said cap opening and an opposite second face adjacent to said compressible component; d) wherein said cap opening and said first face of said seal ring define a flow path for fluid flow between said inlet port to said bypass port when said valve system is in said open position.

25. The assembly of claim 13 wherein said compressible component comprises a plurality of O-rings vertically disposed in series relative to each other.

26. The assembly of claim 13 wherein said compressible component has a bellow-shaped configuration.

27. The assembly of claim 13 wherein said compressible component includes a helical portion.

28. A fluid filter assembly comprising: a) a housing having a first end and an opposite second end; b) a first end member adjoined to said first end, said first end member including a central outlet and at least one inlet port disposed around said central outlet; c) a second end member adjoined to said second end; d) an outlet tube adjoined to said central outlet, said outlet tube including a normal outlet port adjacent to said second end, said inlet port and said normal outlet port having a pressure differential therebetween during operation of said assembly; and e) an assembly component including at least one bypass port; f) a pressure relief valve system including a compressible component adjacent to said bypass port, said compressible component including a sleeve portion comprising a material having a resistance value that substantially corresponds to a predetermined value of the pressure differential, said valve system having a closed position wherein said compressible component prevents fluid flow through said bypass port when the pressure differential is below the predetermined value, said valve system further having an open position wherein said compressible component allows fluid flow through said bypass port when the pressure differential is substantially equal to or greater than the predetermined value.

29. The assembly of claim 28 wherein said assembly component is said outlet tube.

30. The assembly of claim 30 wherein said bypass port is disposed adjacent to said first end.

31. The assembly of claim 28 wherein said compressible component comprises a nonmetallic material selected from thermoset rubbers, thermoplastics and combinations thereof.

32. The assembly of claim 28 wherein said compressible components is disposed circumferentially outside said outlet tube.

33. The assembly of claim 28 wherein said compressible component further includes at least one reed portion adjoined to said sleeve portion.

34. A method for regulating fluid flow in an assembly including a first assembly component including at least one inlet port, a second assembly component including at least one normal outlet port and a third assembly component including at least one bypass port, said inlet port and said normal outlet port having a pressure differential therebetween during operation of said assembly, the steps comprising: a) providing a safety relief valve system comprising: i) a compressible component adjacent said bypass port, said compressible component comprising a material having a resistance value that substantially corresponds to a predetermined value of the pressure differential between the inlet port and the normal outlet port, ii) a closed position wherein said compressible component presses against said bypass port to prevent fluid flow therethrough when the pressure differential is below the predetermined value, and iii) an open position wherein said compressible component uncovers at least a portion of at least one of said bypass port to allow fluid flow therethrough when the pressure differential is substantially equal to or greater than the predetermined value; and b) introducing fluid into said inlet port whereby the fluid flow is regulated to flow through the normal outlet port and the bypass port depending on whether the pressure differential exceeds the predetermined value.

35. The method of claim 34 wherein said compressible component comprises a nonmetallic material.

36. The method of claim 34 wherein an outlet tube includes said normal outlet port and said bypass port.

37. The method of claim 36 wherein said compressible component is provided inside said outlet tube.

38. The method of claim 36 wherein said compressible component is provided circumferentially outside said outlet tube.

39. The method of claim 34 wherein said open position allows fluid flow through at least a portion of at least one bypass port and thereafter through said normal outlet port.

40. A method for regulating fluid flow in an assembly including a first assembly component including at least one inlet port, a second assembly component including at least one normal outlet port and a third assembly component including at least one bypass port, said inlet port and said normal outlet port having a pressure differential therebetween during operation of said assembly, the steps comprising: a) providing a safety relief valve system comprising: i) a compressible component adjacent said bypass port, said compressible component comprising a nonmetallic material having a resistance value that substantially corresponds to a predetermined value of the pressure differential between the inlet port and the normal outlet port, ii) a closed position wherein said compressible component presses against said bypass port to prevent fluid flow therethrough when the pressure differential is below the predetermined value, and iii) an open position wherein said compressible component uncovers at least a portion of at least one of said bypass port to allow fluid flow therethrough when the pressure differential is substantially equal to or greater than the predetermined value; and b) introducing fluid into said inlet port whereby the fluid flow is regulated to flow through the normal outlet port and the bypass port depending on whether the pressure differential exceeds the predetermined value.