AU2014221216A1 - A valve - Google Patents

Abstract

- 28 An improved valve comprises a hollow body with an inlet, an outlet, a passage between the inlet and the outlet, and a valve member mounted within the body. The valve member is moveable between an open position in which the passage is open for fluid to flow from 5 the inlet to the outlet and a closed position in which the passage is substantially closed to substantially prevent fluid flow from the inlet to the outlet. In the open position the valve member locates adjacent an inner peripheral wall of the hollow body. The valve includes one or more projections on the valve member or on the inner peripheral wall. The projections maintain a gap between a surface of the valve member and the inner ) peripheral wall of the body when the valve member moves to the open position. The projections reduce a contact area between the valve member and the wall to reduce a force required for the valve member to return to the closed position. 141 a 146 144c -140 144e 144ai 144b 143 144a 141 144d

Description

Regulation 3.2 AUSTRALIA PATENTS ACT, 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Name of Applicant: LAKE PRODUCTS LIMITED Actual Inventors: HAYNES, Andrew Leo; GIURGIU, Gabriel Ioan; SUMNER, Michael John Address for service AJ PARK, Level 11, 60 Marcus Clarke Street, Canberra ACT in Australia: 2601, Australia Invention Title: A Valve The following statement is a full description of this invention, including the best method of performing it known to us. 66984091 -2 FIELD OF THE INVENTION The invention relates to a valve and in particular, though not solely, to an air admittance valve, for example as may be used in a plumbing arrangement or as may be used in other applications requiring pressure relief. 5 BACKGROUND OF THE INVENTION In the field of plumbing, waste is produced at fixtures such as toilets, sinks and showers, and exits the fixtures through a weir trap. A weir trap is a U-shaped/bent section of pipe that retains a volume of water at the bend. This volume creates a water seal to prevent sewer (and/or other undesirable) gases from entering a building back through the 10 fixture. When water is discharged from a fixture (e.g. toilet is flushed), the displacement of liquid within the pipes creates a pressure differential on either side of the trap. In a closed system, this pressure differential can cause the water within the trap to move, thereby affecting the integrity of the water seal. In modern plumbing, a venting system is used to allow air to be drawn in from outside 15 (rather than through the weir trap) during periods of discharge. This maintains the effectiveness of the trap. Vents also provide a means to release sewer gases outside the building, and typically through the roof of a building. A disadvantage to a simple venting system is that the opening of the vent may get blocked (for example by snow) and/or unwanted material may enter from the outside environment into the plumbing system. 20 An air admittance valve is an alternative/improved venting system which operates to open the vent only during periods of negative pressure (water discharge). At neutral or positive pressures, the valve is closed. When water is discharged by the fixture, the negative pressure within the system causes the valve to open and draw in air from outside to equalise the pressure on either side of the trap. As the pressure neutralises 25 the valve closes to prevent gases from escaping the system. Valves, such as air admittance valves may be used in a variety of applications, in particular those applications where pressure relief is needed. Air admittance valves typically occupy a significant amount of space, especially in the vertical direction. When used within a plumbing system for a building fixture, such as a wash basin for example, 30 difficulties can arise during installation due to the limited vertical space available under the fixture. It is an object of the present invention to provide a valve, such as an air admittance valve, for use in a various arrangements, including plumbing arrangements, or to at least provide the public with a useful choice.

-3 SUMMARY OF THE INVENTION In a first aspect the invention consists in a valve comprising: a hollow body having an inlet, an outlet and a passage between the inlet and the outlet and bounded by an inner peripheral wall of the body, 5 a valve member mounted within the body and moveable between an open position in which the passage is open for fluid to flow from the inlet to the outlet and a closed position in which the passage is substantially closed to substantially prevent fluid flow from the inlet to the outlet, and one or more projections located on the valve member or the inner peripheral wall 10 to maintain a gap between a surface of the valve member and the inner peripheral wall of the body when the valve member moves to the open position where the surface locates adjacent the inner peripheral wall. Preferably the valve member is mounted about the inlet. Preferably the valve member is moveable between the closed and open positions in response to a pressure change within 15 the passage. Preferably the valve comprises a plurality of projections. More preferably the valve member comprises an annular surface and the one or more projections are circumferentially discontinuous relative to the annular surface. Preferably the valve member comprises a main body portion and a flange at an end of 20 the body portion. In some embodiments the valve member may be described as a diaphragm. In some embodiments the valve member is substantially solid. For example the main body portion is substantially solid. Preferably the valve comprises a valve seat at or adjacent the inlet of the valve. Preferably the valve member is moveable between an open position in which the flange is 25 separated from the seat and a closed position in which the flange seals against the seat. Preferably the seat is an annular rim and the diameter of the main body is smaller than the inner diameter of the inlet. In some embodiments the annular rim comprises a tapered profile to reduce the contact surface area between the flange and the rim. In some embodiments the main body portion is received in the inlet in both the open and 30 closed positions. Preferably the valve member extends out of the inlet to extend externally from the hollow body of the valve when the valve member is in the closed position.

-4 In one embodiment the one or more projections are located on the valve member. Preferably the one or more projections are located on a surface of the flange opposing the inner peripheral wall of the valve body to thereby maintain a gap between the surface of the flange and the inner peripheral wall of the body when the valve member 5 moves to the open position to prevent a seal from forming between the surface and the inner peripheral wall and maintain fluid flow/pressure within the gap. Preferably the one or more projections are radially spaced about the flange. In another embodiment the one or more projections are located on the inner peripheral wall of the body. Preferably multiple projections are radially spaced about the inner 10 peripheral wall and configured to abut against a surface of the flange opposing the inner peripheral wall of the body to thereby maintain a gap between the surface and the inner peripheral wall when the valve member moves to the open position to prevent a seal from forming between the surface and the inner peripheral wall and maintain fluid flow/pressure within the gap. Alternatively one projection extends from the inner 15 peripheral wall to engage the body portion of the valve member thereby maintaining a gap between a surface of the valve member opposing the inner peripheral wall and the inner peripheral wall when the valve member moves to the open position to prevent a seal from forming between the surface and the inner peripheral wall and maintain fluid flow/pressure within the gap. 20 Preferably each projection is sized and shaped to reduce a contact surface area between the surface of the valve member and the inner peripheral wall of the body. In some embodiments the projections comprise a tapered profile along at least a contact end of the projection. The tapered profile may be substantially linear, curved or stepped and may comprise a substantially sharp or rounded apex 25 Preferably the projections are formed from a resilient material and each is sized to maintain the gap between the surface of the valve member and the inner peripheral wall when the projection is deformed against the inner peripheral wall under opening pressure of the valve. In some embodiments the valve comprises a cap element configured to couple about an 30 opening of the passage to thereby form the inner peripheral wall, the inner peripheral wall opposing the inlet of the valve. In some embodiments the valve comprises an annular seal configured to locate between the cap element and an outer peripheral wall of the passage. In some embodiments the valve further comprises one or more locating lugs extending from the outer peripheral wall of the passage and the cap element 35 comprises one or more corresponding recesses for engaging the one or more lugs to thereby enable a user to locate the cap over the passage during assembly of the valve.

- 5 Preferably the lugs and recesses cooperate to provide correct orientation between the valve member and the inner peripheral wall. Preferably the valve member is formed from a chemical and/or temperature resistant material. In some embodiments the valve member is formed from a substantially soft 5 and/or resilient and/or a flexible material. For example the valve member is formed from Silicone or a thermoplastic elastomer (TPE) or a thermoplastic polyurethane (TPU) material. In the preferred embodiment the valve of the first aspect is an air admittance valve configured to be used in a plumbing system. Preferably the air admittance valve is configured to couple adjacent a weir trap of the plumbing system. 10 Preferably the valve member is configured to move from the closed state to the open state when the air admittance passage experiences a relatively negative pressure between the air admittance passage and an outside environment, and is configured to move from the open state to the closed state when the air admittance passage experiences a relatively neutral or positive pressure between the air admittance passage 15 and the outside environment. Preferably the valve member is configured to move in response to substantially small relative (negative or positive) pressures between the air admittance passage and the outside environment. Preferably the valve member is configured to move from the closed state to the open state in response to negative pressure between approximately 0 and 20 0.3 Pounds per Square Inch (PSI). Preferably, the valve member is operable/moveable between states when subjected to a pressure differential approximately within the range of -1.0 to 1.0 PSI, more preferably a pressure differential approximately within the range of -0.5 to 0.5 PSI and most preferably a pressure differential approximately within the range of -0.3 to 0.3 PSI. 25 Preferably the valve member is substantially lightweight to respond to substantially small relative pressure between the air admittance passage and the outside environment. Preferably the valve member is between approximately 0.5 to 2.0 grams in weight, more preferably between approximately 0.5 and 1.5 grams in weight, and most preferably between approximately 1.0 to 1.1 grams in weight. 30 In alternative embodiments, the valve of the first aspect may be used in any low pressure differential application, such as in turbochargers or refrigeration units. In a second aspect the invention consists in a plumbing component comprising: a hollow body forming a fluid channel therethrough and having an aperture fluidly connected to the fluid channel, and -6 an air admittance valve operatively connected to the aperture of the body to regulate air delivery into the channel, the valve comprising: a hollow body having an inlet, an outlet and an air admittance passage between the inlet and the outlet and bounded by an inner peripheral wall of the body, 5 a valve member mounted within the body and moveable between an open position in which the passage is open for fluid to flow from the inlet to the outlet and a closed position in which the passage is substantially closed to substantially prevent fluid flow from the inlet to the outlet, and one or more projections located on the valve member or the inner peripheral 10 surface to maintain a gap between a surface of the valve member and the inner peripheral wall of the body when the valve member moves to the open position where the surface locates adjacent the inner peripheral wall. Preferably the air admittance valve is configured to operate in a closed state where the valve seals air flow from an outside environment into the aperture, and in an open state 15 where the valve enables air flow from the outside environment into the channel. Preferably the outlet of the valve is fluidly connected to the aperture of the body. Preferably during operation of the valve, the projections decrease the likelihood of the flange sticking to the wall which in turn reduces the level of pressure change required to cause the valve member to move towards the closed state. 20 Preferably the seat is an annular rim and the only operative engagement in the closed state between the valve member and the inlet is through the flange and the rim. Preferably during operation this arrangement reduces the contact surface area between the valve member and the air admittance passage which in turn reduces the level of pressure change required to cause the valve member to move from the closed state 25 towards the open state. Preferably the annular rim comprises a tapered profile to reduce the contact surface area. The tapered profile may be substantially linear, curved or stepped and may comprise a substantially sharp or rounded apex. Preferably the valve comprises a cap element configured to couple about an opening of 30 the passage to thereby form the wall opposing the seat of the inlet of the valve. Preferably the cap provides the ability to access the passage to remove or install the valve member and/or clean the passage for example.

-7 Preferably the valve further comprises an annular seal configured to locate between the cap element and an outer peripheral wall of the air admittance passage. Preferably the valve further comprises one or more locating lugs extending from the outer peripheral wall of the air admittance passage and the cap element comprises one or more 5 corresponding recesses for engaging the one or more lugs to thereby enable a user to appropriately locate the cap over the air admittance passage during assembly of the valve. Preferably the lugs and recesses cooperate to provide correct orientation between the projections and opposing cap wall (or vice versa in the alternative form described above). 10 Alternatively an integral wall of the passage opposes the valve seat. Preferably the air admittance passage is integral with the hollow body of the plumbing component. Alternatively the air admittance passage is separate and configured to couple about the aperture of the plumbing component. Preferably the hollow body comprises a baffle extending along and partially occluding the 15 aperture and outlet of the air admittance passage to thereby direct fluid flow within the channel away from the outlet and along the channel. Preferably the baffle is arranged so that it does not substantially restrict the flow path through the main hollow body. Preferably a wall of the main hollow body comprises a protruded section that creates a cavity within the main hollow body, and the aperture is 20 formed in the protruded section of the main hollow body, and the baffle extends from the protruded wall section of the pipe within the cavity so that the baffle does not substantially reduce the cross sectional area of the pipe. In some embodiments the baffle follows an internal curvature of an upstream portion of the main hollow body. In the preferred embodiment the aperture is sufficiently un-occluded by the baffle to 25 create sufficient negative pressure within the air admittance passage in response to fluid flow past the aperture to open the valve. In a preferred embodiment the plumbing component is configured to couple to a weir trap of a building fixture. The plumping component may be separately coupled or integral with the weir trap. One end of the hollow body may be configured to couple an end of the 30 weir trap and an opposing end of the hollow body may be configured to couple a drain pipe leading to a remainder of a plumbing system. The ends of the hollow body, weir trap and/or drain pipe may be threaded and the plumbing component may further comprises one or more nuts or knuckle joints configured to be threadably engaged with adjacent ends of the hollow body, weir trap -8 and/or drain pipe to thereby couple the hollow body, weir trap and/or drain pipe together. The component may further comprise one or more annular seals located at the connections between the hollow body, weir trap and/or drain pipe. 5 Preferably the air admittance valve is operative to retain fluid within the weir trap when fluid is discharged from the fixture through the channel of the plumbing component. Preferably, during operation, as fluid traverses through the channel, relative negative pressure is formed in the air admittance passage which causes the valve member to move to the open state, air from the surrounding atmosphere enters the air admittance 10 passage through the open inlet and out the outlet into the channel to thereby neutralise pressure within the channel created by fluid flow and prevent suction of fluid away from the trap, and when pressure is neutralised in the channel, the pressure within the air admittance passage consequently neutralises or becomes positive causing the valve member to move towards the closed state and prevent air from entering the passage and 15 channel. Preferably the plumbing component is configured to couple a weir trap under a wash basin. Preferably the plumbing component, when coupled to the weir trap, extends approximately 100mm to 120mm above the weir trap. In a third aspect the invention consists in a plumbing system coupled to a drain of a 20 building fixture and comprising: a weir trap coupled to the drain for retaining a water seal between the drain and a remainder of the plumbing system, and a plumbing component coupled to an end of the weir trap between the weir trap and the remainder of the plumbing system, the plumbing component comprising of: 25 a hollow body forming a fluid channel therethrough and having an aperture fluidly connected to the fluid channel, and an air admittance valve operatively connected to the aperture of the body to regulate air delivery into the channel and having: a hollow body having an inlet, an outlet and an air admittance 30 passage between the inlet and the outlet and bounded by an inner peripheral wall of the body, -9 a valve member mounted within the body and moveable between an open position in which the passage is open for fluid to flow from the inlet to the outlet and a closed position in which the passage is substantially closed to substantially prevent fluid flow from the inlet to the 5 outlet, and one or more projections located on the valve member or the inner peripheral wall to maintain a gap between a surface of the valve member and the inner peripheral wall of the body when the valve member moves to the open position where the surface locates adjacent the inner peripheral 10 wall. In a fourth aspect the invention consists in an air admittance valve for use in a plumbing system to regulate delivery of air flow into the system, the valve comprising: a body having an air admittance passage defined between an air inlet and air outlet of the body, and 15 a valve member configured to moveably couple the body in an assembled state of the valve, the valve member comprising a main body and a flange extending from an end of the body, and wherein in use the valve member is moveable between an open state where the valve member is separated from a valve seat at the inlet of the body to thereby allow air to flow in the inlet through to the outlet via the passage, and a closed 20 state where only the flange of the diaphragm engages the body at the seat to close the inlet and prevent fluid flow into the passage of the valve, and one or more projections located on the valve member or an inner peripheral wall of the body to maintain a gap between a surface of the valve member and the inner peripheral wall of the body when the valve member moves to the open state where the 25 surface locates adjacent the inner peripheral wall. It will be appreciated any one or more of the above aspects can be provided in combination with any one or more of the above preferred or alternative embodiments or features. The term "comprising" as used in this specification means "consisting at least in part of". 30 When interpreting each statement in this specification that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner.

- 10 It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges 5 of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner. To those skilled in the art to which the invention relates, many changes in construction 10 and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. The invention consists in the foregoing and also envisages constructions of which the 15 following gives examples only. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention will be described by way of example only and with reference to the drawings, in which: Figure 1 is a cross-sectional perspective view of a valve according to some embodiments 20 of the invention in the closed state, Figure 2 is a cross-sectional perspective view of a valve according to some embodiments of the invention in the opened state, Figure 3 is a close-up view of the valve of figure 2 in the opened state, Figure 4 is a sketch of an alternative valve of the invention, 25 Figure 5 is a cross-sectional view of an alternative valve of the invention in the closed state. Figure 6 is a cross-sectional view of an alternative valve of the invention in the closed state. Figure 7 is a schematic of a plumbing system associated with a fixture within a home or 30 building and comprising an air admittance valve, - 11 Figure 8 is a cross-sectional perspective view of a preferred form plumbing component of the invention being utilised in a plumbing system similar to that of figure 7, Figure 9 is a close-up perspective view of an air admittance valve of the plumbing component of figure 8 from the front, and 5 Figure 10 is a perspective view of the plumbing component of figure 8 in the assembled and installed form. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to figure 1 a valve 140 of the invention is shown comprising a generally hollow body 149 having an inlet 142, an outlet 143, and a fluid admittance passage between the 10 inlet 142 and outlet 143. A valve member 144 is moveably mounted within the body 149 to open or obstruct the passage 141 between the inlet 142 and outlet 143 to thereby open and close the valve 140 respectively. In the preferred embodiment, movement of the valve member 144 is pressure actuated. A pressure differential across either side of the valve member 144 (i.e. between the inlet 142 and the passage 141) causes the valve 15 member 144 to move in a direction that equalises the pressure. Figure 1 shows the valve 140 in the closed operative state and figure 2 shows the valve 140 in the open operative state. The passage 141 is bound by an inner peripheral wall 141a of the body 149. During operation, the valve member 144 moves towards peripheral wall 141a to open the valve. To close the valve 140, the valve member 144 20 moves to obstruct the inlet 142. One or more projections 144c are provided within the valve 140 to limit the movement of the valve member 144 as it approaches the open position shown in figure 1. In a conventional valve, a sealing surface of the valve member is typically fully engaged with an inner peripheral wall of the body of the valve to allow provide an effective seal. 25 In the valve 140 of the invention, one or more projections 144c are provided on (or adjacent) the valve member 144 in the open position to maintain a gap between a (normally sealing) surface 144e of the valve member 144 and the inner peripheral wall 141a of the body 149 when the valve member 144 moves to the open position shown in figure 2. The gap that is maintained between the surface 144e and the wall 141a relieves 30 some (preferably approximately/substantially all) of the suction pressure experienced by the surface 144e towards wall 141a. A smaller contact surface area is provided with the wall 141a by the projections 144c as opposed to that of surface 144e. In this manner, relatively small pressure differentials are effective to overcome the suction pressure between the wall 141a and the valve member 144 and thereby move - 12 the valve member 144 away from the wall 141a and towards the closed position. The arrangement thus provides an effective valve for applications requiring actuation via relatively smaller pressure differentials and/or rapid movements/transitions between operative states. The one or more projections 144c are sized to maintain a sufficient gap 5 between the surface 144e and the wall 141a for meeting the valve response requirements of the intended application. It will be appreciated that the shape and/or size of the projections 144c is dependent on the intended application and/or type of material used for the projections 144c. In a preferred embodiment, each projection 144c comprises a tapered profile along at least a 10 contact end of the projection 144c to minimise the contact surface area between the valve member 144 and the inner wall 141a of the valve body in the open state. The tapered profile may be substantially linear, curved or stepped and may comprise a substantially sharp or rounded apex. The valve member 144 is preferably also relatively lightweight to enable a rapid/quick response to relatively small pressure differentials. 15 In the preferred embodiment, the valve member 144 is formed from a material that has any one or more of the following combination of properties: substantially deformable/flexible, substantially soft, substantially durable, substantially resistant and/or impermeable to chemicals, substantially resistance to extreme temperatures and/or temperature changes, and/or substantially resilient. In the preferred embodiment, 20 the valve member 144 is formed from a soft plastics material, such as a Silicone material, but may alternatively be formed from a polymer material such as TPE or TPU. The valve member 144 is moulded into a single part having a major body portion 144a, and integral flanged end portion 144b. In some embodiments, the valve member may have one or more integral projections 144c on the flange 144b. The projections 144c are 25 sized and shaped to maintain a sufficient gap between the surface 144e of the flange 144b and the wall 141a (for example in accordance with the above gap dimensions of the preferred embodiment) after deformation of the projections 144c under opening pressure. In the preferred embodiment, each projection 144c has a height that is sized to allow for some level of deformation under pressure. The deformed height of each 30 projection 144c is sufficient for maintaining the desired gap width. In the preferred embodiment, the non-deformed height of each projection 144c is approximately 0.1mm to 1mm, more preferably between 0.2 and 0.8mm and most preferably approximately 0.35mm. In alternative embodiments, the valve member 144 and/or the one or more projections 144c are formed from a relatively rigid material and are not deformable. In 35 the preferred embodiment the size of the gap that is maintained in the open position is approximately between 0.1mm and 2mm, more preferably between 0.5mm and 1mm, and most preferably approximately 0.7mm. In the preferred embodiment, the contact - 13 surface area between the valve member 144 and the wall 141a in the open position is approximately between 0.5mm 2 and 2mm 2 , more preferably between 1mm 2 and 1.5mm 2 , and most preferably approximately 1.4mm 2 . In the preferred embodiment shown the one or more projections 144c are provided on the surface 144e of the valve member 144. 5 In yet another alternative embodiment, the one or more projections are not provided on a surface of the valve member 144 but may project from another location within the valve 140 to limit the movement of the valve member 144 and maintain the gap between the surface 144e and the internal wall 141a. For example, a series of radially spaced projections similar to 144c may extend from wall 141a towards the valve member 144. 10 In this manner, the surface 144e of the valve member engages with the projections of the wall 141a (instead of the wall 141a) in the open position, thereby maintaining a gap between the wall 141a and the surface 144e. In another configuration of this alternative embodiment, one or more substantially elongate projections or stands may extend towards another portion of the valve member 144, such as the major body 144a instead 15 of the flange 144b, through the inner periphery of the flange 144b. In such a configuration (illustrated in figure 4), movement is limited by the engagement of the one or more projections 144c with the major body 144a of the valve member 144 as the member 144 moves towards the open position. Once again, the size of the projections is to allow a sufficiently sized gap to be maintained between the surface 144e and the wall 20 141a as the member 144 is moved to the open position under opening pressure. The projections may be formed as ribs, feet, stands, lugs or any other type of protrusion suitable for achieving the abovementioned operation of the valve 140. In any one of the embodiments and/or configurations described, the one or more projections are preferably not continuous relative to the circumference of the surface 25 144e. The arrangement of the projections of the valve 140 preferably allows fluid to flow from the inlet 142 and into the passage through the gap that is maintained between the surface 144e and the wall 141a. In this manner, the suction pressure between the surface 144e and the wall 141a is minimised. In the preferred embodiment shown in figures 1-3, the projections 144c are circumferentially discontinuous and radially spaced 30 about surface 144e. In the alternative embodiment, where similar projection to 144c are provided on wall 141a, the projections are aligned with surface 144e and also circumferentially discontinuous and radially spaced relative to the surface 144e. Referring back to figure 1, in the preferred embodiment, the valve member 144 is formed as a single part having a major body portion 144a with an integral flanged end 35 144b. The valve member may be described as a diaphragmThe flanged end 144b locates adjacent the valve inlet 142 in the closed position and adjacent the wall 141a in the open position. In the closed position, the flanged end 144b abuts against a valve seat 145.

- 14 This contact surface area of this engagement is preferably minimised to reduce the pressure differential required to open the valve. In one embodiment the valve seat 145 comprises a reduced cross-section to minimise the contact surface area. In a preferred embodiment, the valve seat 145 comprises a tapered profile to minimise the contact 5 surface area between the valve member 144 and the seat 145 in the closed state. The tapered profile may be substantially linear, curved or stepped and may comprise a substantially sharp or rounded apex. The major body portion 144a of the valve member 144 does not contact the wall of the inlet 142 in the closed position thereby further reducing the contact surface area between the valve member 144 and the valve body 10 149 in the closed position. This arrangement provides actuation via relatively smaller pressure differentials and/or rapid movement/transition from the closed to open state of the valve 140. In the preferred embodiment the inlet 142 and major body portion 144a are formed to be concentrically alignable in the assembled and/or operative states of the valve 140. The 15 body portion 144a of the valve member 144 is preferably formed to have a tapered end 144d opposing the flanged end 144b to guide the major body portion 144a into alignment with the valve inlet 142. In this manner, the valve member 144 is self aligning with the inlet 142 of the valve 140 during assembly/operation. The major body portion 144a may take on any shape, size or profile as desired by the application. For example, 20 the major body portion 144a may be relatively wide (i.e. almost touching the inlet 142) or relatively thin, and/or the body 144a may have a smooth rounded end 144d or a sharp/apexed end 144d. The major body portion 144a is preferably formed with an internal cavity 144ai. A weighted element may be accommodated within the cavity 144ai for example to allow the valve member 144 to further decrease the transition time of the 25 valve member 144 into the closed position. Alternatively the major body portion 144a may be weighted or thickened proximal to and/or at end 144d. Alternatively the major body portion 144a may be substantially solid (i.e. does not contain a cavity). For example, in the embodiments illustrated in Figures 10 and 11 the valve member 144 is substantially solid and is substantially without a cavity extending into the body portion 30 144a of the valve member. The valve 140 comprises a cap element 146 configured to couple about an open end 141b of the passage 141 and form the inner wall 141a adjacent the flange 144b of the valve member 144. A seal in the form of an 0-ring 147 is provided on an outer flange 141c of the passage 141 to sealably couple the cap 146 about the opening 141b of the 35 passage 141. Referring also to figure 10, a locator/lug 148 projects from the outer peripheral wall of the air admittance passage 141 for engaging a corresponding recess 146a formed through the cap wall at an open end of the cap 146. The locator 148 ensures appropriate alignment between the cap 146 and the open end 141b of the air - 15 admittance passage 141 during coupling so that the inner wall 141a is in turn aligned appropriately relative to the upper surface of the flange 144b of the valve member 144. This allows the valve 140 to be assembled easily and ensures effective operation in accordance with the above described advantages. A screw on cap for example may be 5 retained in a state where the surface of the flange 144b and the wall 141a are inappropriately aligned to achieve the desired gap during operation of the valve 140. In one alternative embodiment, the inlet 142 may be provided as a grill or opening in the cap element 146 (instead of an opening in the body at 142 as shown in the figures). In this manner, the valve member 144 moves towards the cap 146 to close the valve 140 10 and away from the cap 146 to open the valve 140. The gap to be formed would be adjacent a region of the inner wall 141a of the passage 141 that opposes the side to the cap 146. The valve 140 of the invention may be utilised in any one of a number of applications that require actuation via low pressure differentials including, but not limited to, 15 turbochargers, refrigerators and/or plumbing systems. The valve 140 may be formed as part of a fluid regulating pipe 150, for example an elbow as shown in figure 1. The pipe 150 comprises a main hollow body onto which the valve 140 is (integrally) tapped via an aperture 151. The outlet 143 of the valve 140 is fluidly connected to the aperture 151 and the interior of the pipe. As fluid flows through the pipe 150 past the aperture 151, a 20 pressure is experienced within the passage 141 of the valve 140. Changes in this pressure cause the valve member 144 to move towards the open and closed positions accordingly. Referring to Figure 5, in some embodiments the valve member is substantially solid (i.e. does not contain a cavity). For example, in the embodiments illustrated in Figures 10 25 and 11 the valve member 144 is substantially solid and is substantially without a cavity extending into the body portion 144a of the valve member. Compared to a valve member that has an internal cavity, a solid valve member is heavier and therefore can decrease the transition time of the valve member 144 into the closed position. As shown in Figures 5 and 6, in some embodiments the valve member extends out of the 30 inlet to extend externally from the hollow body 149 of the valve when the valve member is in the closed position against the seat 145 of the valve. In such an embodiment, the valve member provides a visual indicator of the valve position; when the valve member extends from the hollow housing the valve is closed, and when the valve member does not extend from the hollow body or extends less from the hollow body the valve is open 35 or not closed. In some embodiments the valve member may be formed of a coloured - 16 material, for example the valve member may be coloured red, to provide visual indication of the valve member position. Furthermore, as the valve member may protrude from the hollow body, the valve member may be manually manipulated from outside the hollow body. It is not necessary 5 to remove the cap 146 to manipulate the valve member 144 from outside of the hollow body. In the embodiments of Figures 5 and 6 the baffle 152 that shields the aperture 151 and the valve outlet 143 is arranged so that it does not substantially restrict the flow path through the pipe or main hollow body. For example, in Figure 1 the baffle 151 creates a 10 narrow point or restriction in the flow path of the pipe. That is, the internal cross sectional area of the pipe is reduced at the location of the valve outlet 143 due to the baffle within the flow path through the pipe. In Figure 5, the wall 157 of the pipe 150 comprises a protruded section 157a that creates a cavity 171 within the pipe. The aperture 151 is formed in the protruded section of the pipe, or the outlet of the valve is 15 coupled to the protruded section of the pipe. The baffle extends from the protruded wall section of the pipe in the cavity 171 so that the baffle does not substantially reduce the cross sectional area of the pipe. As shown, the baffle 152 is substantially outside of a minimum cross sectional area of a flow path 171 defined by a portion of the pipe upstream of the protruded wall section. Due to the protruded wall section of the pipe 20 and the arrangement of the baffle within the cavity provided by the protruded wall section, the baffle remains substantially outside of a minimum cross sectional area defined by an upstream portion of the pipe, a downstream portion of the pipe, or by an upstream or downstream mating component, such as a mating plumbing fitting. In the embodiment of Figure 6, the baffle approximately follows or maintains a minimum 25 cross sectional area defined by an upstream portion of the pipe. The baffle 152 approximately follows or maintains a minimum cross sectional area defined by an upstream portion of the pipe and a downstream mating component 172. In some embodiments the baffle follows a curvature of an upstream portion of the pipe or main hollow body 150. The outlet of the valve couples to the aperture 151 of the pipe above 30 the baffle in a protruded wall section 157a of the pipe. The baffle is formed in a cavity of the pipe formed by the protruded wall portion 157a. In the preferred embodiment, the valve 140 is for use as part of a plumbing component in a plumbing system as will be described in further detail below. The valve 140 allows for a low profile plumbing component that can be installed in a plumbing system directly 35 underneath the fixture/fitting without interfering or touching the fixture/fitting. For - 17 example, the valve 140 can be appropriately installed above a weir trap of a plumbing system without interfering with the fixture/fitting located directly above the trap. Conventional air admittance valves have a substantially large vertical profile and as such present difficulties during installation beneath wash basin or other fixtures with limited 5 space underneath. Referring to figure 7, a building fixture/fitting such as a wash basin typically provides a limited amount of space underneath the fixture for plumbing. In particular, the gap, g, between the bottom of the fixture and the top of the weir trap is conventionally substantially small and/or restricted. The air admittance valve 140 of the invention is well suited for such applications as it has a substantially small vertical profile 10 due to the size of valve 140 and its associated components. In some configurations the height, x, of the valve 140 is between approximately 5mm and 50mm. In some configurations the height, x, of the valve 140 is between approximately 10mm and 30mm. In some configurations the height, x, of the valve is between approximately 15mm and 20mm. In some embodiments, the valve 140 and the pipe 150 (if formed as a 15 separate component from the remainder of the plumbing system) form a plumbing component that has an overall vertical profile, Y, which is configured to extend minimally above a weir trap 130 when installed in a plumbing system of a fixture. In some configurations, the valve 140 locates between approximately 75mm to 200mm above an upper end of a weir trap when installed. In some configurations, the valve 140 locates 20 between approximately 90mm to 150mm above an upper end of a weir trap when installed. In some configurations, the valve 140 locates between approximately 100mm to 120mm above an upper end of a weir trap when installed. Referring now to figure 7, a plumbing system 100 is shown comprising a fixture 110 connected to a drainpipe 120 including a weir trap 130. Waste from the fixture 110 is 25 flushed through the drainpipe 120 and unpleasant/toxic gases within the drainpipe are prevented from returning back up the fixture by action of a water seal created within the weir trap 130. An air admittance valve 140 is tapped into the drainpipe 120 adjacent/after the weir trap 130 to equalise pressure within the drainpipe 120 during periods of negative pressure created by flushing. Pressure equalisation ensures the water 30 seal is not compromised immediately after flushing when the pressure within the drainpipe is usually negative. The air admittance valve 140 is operative based on the pressure within the drainpipe. When the pressure is negative (lower on the outlet 143 side of the valve member 140 than atmospheric pressure on the inlet 142 side of the valve member 140), the air admittance valve opens to allow air from the surrounding 35 atmosphere into the drainpipe 120 to equalise the pressure within the pipe 120. When the pressure is neutral or positive, the air admittance valve shuts or closes to stop unnecessary air admittance. Air admittance valve 140 is provided as part of a plumbing - 18 component or fitting 150 that is integral with or that can connect to a drainpipe system 100 and form part of the drainpipe 120. Referring now to figure 8, a close up cross-sectional view of a preferred form plumbing system 100 is shown, including a drainpipe 120 having a weir trap section 130 and an air 5 admittance valve 140 coupled adjacent the weir trap 130. The air admittance valve 140 taps into the drainpipe 120 via an aperture 151 in a wall of the drainpipe 120. The air admittance valve 140 is provided as part of a plumbing component or fitting 150 having an integral drainpipe section 155 that is either integral with or configured to couple the weir trap 130 and form part of the drainpipe 120. An air admittance passage 141 of the 10 valve 140 extends from the aperture 151 to introduce air from atmosphere into the drainpipe 120 when the valve 140 is open. Either end of the air admittance passage 141 is a valve input 142 and valve output 143. The valve output 143 is fluidly connected to the aperture 151 of the drainpipe 120/drainpipe section 150. A moveable valve member 144 is coupled at the valve input 142 to open and close the valve 140 accordingly. In the 15 preferred embodiment the valve member is removable from the passage 141 of the valve 140. During operation, as liquid waste is flushed down the drainpipe 120 in the direction A, a negative/suction pressure is created by the moving liquid at the aperture 151. This pressure is observed by the valve member 144 mounted within the valve 140 which is 20 caused to move in the direction of the pressure force (away from the valve input 142). Movement of the valve member 144 opens the valve input 142 allowing air to enter the air admittance passage 141 from the surrounding atmosphere. This state is shown in figure 2. Air traverses through the passage 141 and into the drainpipe 120 from the output 143 of the valve 140. The injection of air into the drainpipe 120 acts to equalise 25 the pressure on either side of the weir trap 130 after flushing which maintains the integrity of the water seal produced by the trap 130. When pressure within the drainpipe 120 neutralises or becomes positive, the valve member 144 no longer experiences a suction force and is caused by gravity to move into the closed position where the input 142 is sealed off from the surrounding atmosphere. This state is shown in figure 1. A 30 positive pressure within the air passage may encourage movement from the open position to the closed position and in an alternative embodiment it is this pressure that predominantly encourages movement of the valve member between these two operative states. In the preferred embodiment, the valve member 144 and valve 140 are responsive to relatively small pressure changes/differentials and do not need to rely 35 heavily on gravity for example to change between states. This is achieved through the design of a small contact surface area between the valve member and the interior of the valve at the open and closed states.

- 19 Referring to figure 9, the valve member 144 comprises a main body portion 144a terminating in a flanged end 144b. In the assembled form of the valve 140, the flange 144b is located adjacent a valve seat 145 at the input 142 of the valve 140. In the closed operative state of the valve member 144, the flange 144b abuts and seals against the 5 valve seat 145 to prevent input air flow and in the open operative state of the valve member 144, the flange 144b disengages from the seat 145 to allow input air flow. In the preferred embodiment the valve is configured to minimise a contact surface area between the valve member and the passage in one or both the closed and open operative states of the valve. A peripheral wall of the major body 144a of the valve 10 member 144 is parallel to and separated from a peripheral wall 142a of the input 142 of the valve 140. In this manner, the major body 144a does not contact the peripheral wall 142a at any operational state of the valve member 144. The flange 144b is the only portion of the valve member 144 that contacts the input 142 when the valve 140 is in the closed state. This reduces the sealing contact area between the valve member 144 and 15 the valve input 142 meaning a lower suction pressure threshold is required to move the valve member 144 away from the seat 145 and into the open position, than if the contact area was greater due to other portions of the valve member 144 contacting the input 142. A lower suction pressure threshold, results in a quicker response time in opening the valve 140 and/or a more sensitive response to pressure differentials within the 20 drainpipe 120. In the preferred embodiment, the valve seat 145 is substantially rounded and/or apexed at the end adjacent the flanged end 144b of the valve member to minimise the contact surface area between the seat 145 and the valve member 144. In the preferred embodiment, one or more projections or feet 144c are provided on a surface of the flange 144b adjacent an inner wall 141a of the air admittance passage 25 141. In the fully open position/state of the valve 140, the feet 144c of the valve member come into contact with the wall 141a of the air admittance passage 141. The feet 144c reduce the contact area between the flange 144b and the inner wall 141a to reduce sticking of the flange surface 144e against the inner wall 141a. The reduction in sticking results in a quicker response time of the valve 140 when moving from the fully open 30 operative state towards the closed state. The feet 144c are preferably circumferentially spaced about the flange 144b with each foot extending along a substantial portion of the width of the flange 144b. In the preferred embodiment, four feet are spaced about the flange 144b but in alternative embodiments any number of feet 144c may be provided. In the preferred embodiment, each foot 144c comprises a substantially rectangular 35 cross-section. In alternative embodiments the feet 144c may take on other shapes, such as semi-cylindrical or semi-spherical for example, the same or different sizes and/or distributions across the surface of the flange 144b. In yet another alternative, the feet 144c may be provided on the inner wall 141a. The flange surface adjacent the wall may - 20 be substantially planar/flat with no feet/projections. Feet 144c may be provided on both the flange surface and the inner wall in another alternative embodiment. The valve 140 comprises a cap element 146 configured to couple about an open end 141b of the air admittance passage 141 and form the inner wall 141a adjacent the flange 5 144b of the valve member 144. A seal in the form of an 0-ring 147 is provided on an outer flange 141c of the air admittance passage 141 to sealably couple the cap 146 about the opening 141b of the passage 141. Referring also to figure 10, a locator/lug 148 projects from the outer peripheral wall of the air admittance passage 141 for engaging a corresponding recess 146a formed through the cap wall at an open end of the cap 146. 10 The locator 148 ensures appropriate alignment between the cap 146 and the open end 141b of the air admittance passage 141 during coupling so that the inner wall 141a is in turn aligned appropriately relative to the upper surface of the flange 144b of the valve member 144. The recess 146a is generally 'L' shaped or comprises two orthogonal components 146ai/146aii. This shape enables a user to first locate (traversing the 15 projection 148 through 146ai) and then vertically/longitudinally lock (traversing the projection 148 through 146aii) the cap 146 onto the passage 141. The locator 148 preferably forms a friction fit with the recess 146a. The locator 148 may be formed from a material that is relatively more resilient/deformable than that of the cap element 146 to enable an effective friction fit between the two components 146a and 148. The locator 20 148 and/or recess 146a may be any other complementary shapes appropriate for locating the cap onto the passage. It will be appreciated that any number of locators and corresponding recesses may be incorporated to fit the cap 146 onto the passage 141. In some embodiments a pair of locators 148 and corresponding pair of recesses 146a are provided on either side of the valve 140 and cap element 146. In some embodiments 25 four locators 148 and corresponding recesses 146a are provided, preferably equi-spaced circumferentially on the valve 140 and the cap element 146. To assemble the plumbing component 150, the valve member 144 of the valve 140 is first inserted through the open end 141b of the air admittance passage 141 and the flange 144b is rested on the valve seat 145. The seal 147 is placed onto the annular 30 flange 141c of the air admittance passage 141 and the cap 146 is then located on top of the seal 147 to close the open end 141b. The cap 146 is located by inserting the locator 148 through first leg 146ai of the recess 146a of the cap 146 and then vertically locked by rotating the cap 146 to move the locator 148 through the second leg 146aii of the recess 146a. To disassemble for maintenance for example, the cap 146 is unlocked and 35 the removed from the open end 141b of the passage 141 and the valve member 144 is then also removed from passage 141. In some embodiments, where the plumbing component 150 is separate from other pipe sections of the pipe system 100, the plumbing component 150 is fitted into an existing plumbing system in a similar manner - 21 to other drainpipe sections. The component 150 is preferably coupled adjacent a weir trap 130 of the system 100 to help maintain the integrity of the water seal of the trap 130 during operation of the system 100. Referring to figures 8 and 10, in the assembled form the valve 140 is coupled to the 5 drainpipe section 155 to form an overall plumbing component 150. In the preferred embodiment the air admittance passage 141 extends integrally from a wall of the body 156 of the drainpipe section 151 at the aperture 151. In alternative embodiments, the valve 140, including the air admittance passage 141 is separate from and can be coupled about the aperture 151 of the drainpipe 120 or drainpipe section 155. The drainpipe 10 section 151 comprises a baffle 152 extending across and substantially shielding the aperture 151. The baffle 152 appropriately directs water flow along the drainpipe 120 and discourages it from entering the air admittance passage 141 through aperture 151. The baffle 152 does not fully occlude the aperture 151 to allow the suction of air through the aperture 151 and into the drainpipe 120. 15 The drainpipe section 155 of the plumbing component 150 is bent along its length but in alternative embodiments it may be a substantially straight section or it may comprise any number of bends, each bend formed with any desired angle. It will be appreciated that the pipe system may comprise a single continuous pipe member or any number of two or more pipe sections separably coupled to form a continuous liquid flow path. Ether 20 end of the drainpipe section 155 may be integral with an adjacent pipe section (such as a weir trap or another drainpipe section) or may be formed to separably couple another pipe section of the plumbing system 100. In the latter case, the end 153 of pipe section 155 may couple the corresponding end 131 of the weir trap 130 via any conventional coupling means or mechanism known in the art. Similarly, the opposing end 154 of the 25 drainpipe section 155 may separably couple the drainpipe section 160 also via any conventional coupling means or mechanism known in the art. Such conventional coupling means or mechanisms include, but are not limited to, threaded couplings securable via locknuts and/or knuckle joints for example. The ends of the drainpipe sections 130/155/160 may comprise suitable formations necessary to achieve the associated 30 coupling and/or one or more sealing members may be provided to seal the connections or joints between the adjacent pipe sections 130/155/160. The hollow body 156 of the drainpipe section 155 of the plumbing component 150 is preferably formed from a plastics material, such as Polypropylene. The valve member 144, seal 147 and locator 148 are preferably formed from a substantially resilient plastics 35 material, such as Silicone or a flexible polymer such as a TPE or TPU. The remaining components of the plumbing system 100 can be formed from any other material suited for the application as is known in the art.

- 22 The foregoing description of the invention includes preferred forms thereof. Modifications may be made thereto without departing from the scope of the invention as defined by the accompanying claims.

Claims (33)

1. A valve comprising: a hollow body having an inlet, an outlet and a passage between the inlet and the outlet and bounded by an inner peripheral wall of the body, 5 a valve member mounted within the body and moveable between an open position in which the passage is open for fluid to flow from the inlet to the outlet and a closed position in which the passage is substantially closed to substantially prevent fluid flow from the inlet to the outlet, and one or more projections located on the valve member or the inner peripheral wall to ) maintain a gap between a surface of the valve member and the inner peripheral wall of the body when the valve member moves to the open position where the surface locates adjacent the inner peripheral wall.

2. A valve as claimed in claim 1 wherein the valve member is mounted about the inlet.

3. A valve as claimed in claim 1 or claim 2 wherein the valve member is moveable 5 between the closed and open positions in response to a pressure change within the passage.

4. A valve as claimed in any one of claims 1 to 3 comprising a plurality of projections.

5. A valve as claimed in claim 4 wherein the valve member comprises an annular surface and the projections are circumferentially discontinuous relative to the annular 0 surface.

6. A valve as claimed in any one of claims 1 to 5 wherein the valve member comprises a main body portion and a flange at an end of the body portion.

7. A valve as claimed in claim 6 wherein the main body portion is substantially solid.

8. A valve as claimed in claim 6 or claim 7 wherein the valve comprises a valve seat at 5 or adjacent the inlet of the valve.

9. A valve as claimed in claim 8 wherein the valve member is moveable between an open position in which the flange is separated from the seat and a closed position in which the flange seals against the seat.

10. A valve as claimed in claim 9 wherein the seat is an annular rim and the diameter 0 of the main body is smaller than the inner diameter of the inlet. - 24 11. A valve as claimed in claim 10 wherein the annular rim comprises a tapered profile to reduce the contact surface area between the flange and the rim.

12. A valve as claimed in any one of claims 6 to 11 wherein the main body portion is received in the inlet in both the open and closed positions. 5 13. A valve as claimed in any one of claims 1 to 12 wherein the valve member extends out of the inlet to extend externally from the hollow body of the valve when the valve member is in the closed position.

14. A valve as claimed in any one of claims 1 to 13 wherein the one or more projections are located on the valve member. ) 15. A valve as claimed in any one of more of claims 6 to 12 wherein the one or more projections are located on a surface of the flange of the valve member opposing the inner peripheral wall of the valve body to thereby maintain a gap between the surface of the flange and the inner peripheral wall of the body when the valve member moves to the open position to prevent a seal from forming between the surface of the flange and the 5 inner peripheral wall to maintain fluid flow or pressure within the gap.

16. A valve as claimed in claim 15 wherein the projections are radially spaced about the flange of the valve member.

17. A valve as claimed in any one of claims 1 to 10 wherein the one or more projections are located on the inner peripheral wall of the body. ) 18. A valve as claimed in claim 17 wherein multiple projections are radially spaced about the inner peripheral wall and configured to abut against a surface of the valve member opposing the inner peripheral wall of the body to thereby maintain a gap between the surface and the inner peripheral wall when the valve member moves to the open position to prevent a seal from forming between the surface and the inner peripheral wall 5 to maintain fluid flow/pressure within the gap.

19. A valve as claimed in claim 17 wherein one projection extends from the inner peripheral wall to engage the body portion of the valve member to thereby maintain a gap between a surface of the valve member opposing the inner peripheral wall and the inner peripheral wall when the valve member moves to the open position to prevent a seal from 0 forming between the surface and the inner peripheral wall to maintain fluid flow/pressure within the gap. - 25 20. A valve as claimed in any one of claims 1 to 19 wherein each projection is sized and shaped to reduce a contact surface area between the surface of the valve member and the inner peripheral wall of the body.

21. A valve as claimed in claim 20 wherein each projection comprises a tapered profile 5 along at least a contact end of the projection.

22. A valve as claimed in any one of claims 1 to 21 wherein the projections are formed from a resilient material and each is sized to maintain the gap between the surface of the flange and the inner peripheral wall when the projection is deformed against the inner peripheral wall under opening pressure of the valve. ) 23. A valve as claimed in any one of claims 1 to 22 wherein the valve comprises a cap element configured to couple about an opening of the passage to thereby form the inner peripheral wall, the inner peripheral wall opposing the inlet of the valve.

24. A valve as claimed in claim 23 wherein the valve comprises an annular seal configured to locate between the cap element and an outer peripheral wall of the passage. 5 25. A valve as claimed in claim 23 or 24 wherein the valve further comprises one or more locating lugs extending from the outer peripheral wall of the passage and the cap element comprises one or more corresponding recesses for engaging the one or more lugs to thereby enable a user to locate the cap over the passage during assembly of the valve.

26. A valve as claimed in claim 25 wherein the lugs and recesses cooperate to provide ) correct orientation between the valve member and the inner peripheral wall.

27. A valve as claimed in any one of claims 1 to 26 wherein the valve member is formed from a chemical and/or temperature resistant material.

28. A valve as claimed in any one of claims 1 to 27 wherein the valve member is formed from a substantially soft and/or resilient and/or a flexible material. 5 29. A valve as claimed in any one of claims 1 to 28 wherein the valve member is formed from Silicone or a thermoplastic elastomer (TPE) or a thermoplastic polyurethane (TPU) material.

30. A valve as claimed in any one of claims 1 to 29 wherein the valve is an air admittance valve configured to be used in a plumbing system, the fluid passage between 0 the inlet and the outlet being an air admittance passage. - 26 31. A valve as claimed in claim 30 wherein the air admittance valve is configured to couple adjacent a weir trap of the plumbing system.

32. A valve as claimed in claim 32 wherein the valve member is configured to move from the closed position to the open position when the air admittance passage experiences 5 a relatively negative pressure between the air admittance passage and an outside environment, and is configured to move from the open position to the closed position when the air admittance passage experiences a relatively neutral or positive pressure between the air admittance passage and the outside environment.

33. A valve as claimed in claim 32 wherein the valve member is configured to move ) from the closed position to the open position in response to negative pressure between approximately 0 and -0.3 Pounds per Square Inch.

34. A valve as claimed in claim 32 or 33 wherein the valve member is moveable between the open and closed positions when subjected to a pressure differential approximately within the range of -1.0 to 1.0 PSI. 5 35. A valve as claimed in any one of claims 30 to 34 wherein the valve member weighs between approximately 0.5 to 2.0 grams in weight.

36. A valve as claimed in any one of claims 1 to 29 wherein the valve is adapted to be used in a low pressure differential application, such as in turbochargers or refrigeration units. ) 37. A plumbing component comprising: a main hollow body forming a fluid channel therethrough and having an aperture fluidly connected to the fluid channel, and an air admittance valve as claimed in any one of claims 30 to 37, the outlet of the air admittance valve operatively connected to the aperture of the main hollow body to 5 regulate air delivery into the channel.

38. A valve as claimed in claim 37 wherein the air admittance valve is configured to operate in a closed position where the valve seals air flow from an outside environment into the aperture, and in an open position where the valve enables air flow from the outside environment into the channel. 0 39. A plumbing component as claimed in claim 37 wherein the main hollow body comprises a baffle extending along and partially occluding the aperture and outlet of the - 27 air admittance passage to thereby direct fluid flow within the channel away from the outlet and along the channel.

40. A plumbing component as claimed in claim 39 wherein the baffle is arranged so that it does not substantially restrict the flow path through the main hollow body. 5 41. A plumbing component as claimed in claim 40 wherein a wall of the main hollow body comprises a protruded section that creates a cavity within the main hollow body, and the aperture is formed in the protruded section of the main hollow body, and the baffle extends from the protruded wall section of the pipe within the cavity so that the baffle does not substantially reduce the cross sectional area of the pipe. ) 42. A plumbing component as claimed in claim 41 wherein the baffle follows an internal curvature of an upstream portion of the main hollow body.

43. A plumbing component as claimed in any one of claims 37 to 42 wherein the aperture is sufficiently un-occluded by the baffle to create sufficient negative pressure within the air admittance passage in response to fluid flow in the channel past the aperture 5 to open the valve.

44. A plumbing component as claimed in any one of claims 37 to 43 wherein the plumbing component is configured to couple to a weir trap of a building fixture.

48. A plumbing component as claimed in claim 44 wherein the plumping component is integrally formed with the weir trap. ) 49. A plumbing component as claimed in claim 44 wherein one end of the main hollow body is be configured to couple an end of the weir trap and an opposing end of the main hollow body is configured to couple a drain pipe leading to a remainder of a plumbing system.

50. A plumbing system coupled to a drain of a building fixture and comprising: 5 a weir trap coupled to the drain for retaining a water seal between the drain and a remainder of the plumbing system, and a plumbing component as claimed in any one of claims 37 to 46 coupled to an end of the weir trap between the weir trap and the remainder of the plumbing system.

51. A valve or plumbing component or plumbing system substantially as herein 0 described with reference to and as illustrated by any one or more of the accompanying figures.