TECHNICAL FIELD

The present invention relates to an air valve device for equalizing waste water pipe underpressures while preventing odours from escaping the waste water piping system. The present invention also relates to a waste water piping system.

BACKGROUND

A waste pipe, or soil pipe, is typically fitted in a building for the purpose of leading away waste water that may be generated by water closets, baths, wash basins, kitchen sinks, etc. For the purpose of enabling a flow of waste water in a waste pipe the waste pipe may have a relatively large inner diameter allowing the waste pipe to be partly air filled. Moreover, the waste pipe may be arranged such that waste water can flow away from the waste water generator, i.e. from the water closet, bath tub, wash basin, or kitchen sink, etc, by means of gravity. When waste water includes sewer the waste pipe may hold sewer gases that may be generated by the decomposition of organic household wastes or industrial wastes.

An air valve can be fitted to the upper end of the waste pipe, or soil pipe, to which water closets, baths, wash basins, kitchen sinks, etc. can be connected via a liquid trap seal. In the field of plumbing a liquid trap seal, may be embodied as a water seal. The liquid trap seal may thus be used for preventing sewer gases from escaping a waste pipe into a building. When waste water flows away from a waste water generator, such as e.g. when a water closet is flushed, the waste water flowing down the waste pipe may cause an under-pressure to be formed in the waste pipe in the vicinity of the liquid trap seal. In the absence of an air valve, such an under-pressure may cause the liquid in the liquid trap seal to be sucked away allowing sewer gases to pass freely into the room in which the waste water generator, e.g. the water closet, comprising the liquid trap seal is installed.

The air valve will normally close when the pressure in the pipe to which the valve is connected is the same as the pressure outside the pipe. The air valve may also seal the pipe channel effectively when the pressure in the pipe is higher than the ambient pressure. When the pressure in the pipe is lower than the ambient pressure, however, the valve will open and allow ambient air to enter so as to equalize the under-pressure. This prevents the liquid in the water-seal of the wash basins etc. from being sucked away therefrom. If the liquid were removed from the water-seal of e.g. a water closet, then air and sewer gases from the waste water pipe would be allowed to pass freely into the room where the water-seal was installed. When fitted to a waste pipe, the air valve may also prevent odours as well as warm and moist air from flowing out from an end portion of the waste pipe.

EP 0 867 569 discloses an air valve including a vertically positioned pipe connector. The vertically positioned pipe connector can be fitted to the upper end of a vertical portion of a waste pipe. According to EP 0 867 569, the vertically positioned pipe connector has an upper end that forms a valve seat in the form of a ring-shaped, horizontal sealing ridge. Moreover, EP 0 867 569 teaches that the air valve includes a vertically movable valve plate which carries on its underside an annular sealing washer whose radially inner and outer edge-parts are able to rest sealingly onto concentrically, upwardly facing valve-seat rings, wherewith the washer seals the annular gap between said ring seats. The valve washer normally rests on the two ring-shaped, horizontal sealing ridges under the influence of the combined weight of the sealing washer and the guided plate carrying the washer. The valve opens in response to pressure differences.

US209975 Al shows, in figure 1, a vertical section of an air valve having a chamber A and a vertically positioned pipe B, the vertically positioned pipe B connecting with a horizontally positioned waste water pipe. The lower part of the disclosed air valve chamber A has an opening C for admitting air up into the chamber A, so that the admitted air can flow sideways to said vertically positioned pipe B, and then vertically downwards through the vertically positioned pipe B, and thereafter the admitted air can make yet another 90 degree bend to finally flow in a horizontal direction in the horizontally positioned waste water pipe.

SUMMARY

The present invention relates to the problem of achieving an improved waste water piping system, and/or an improved air valve. An aspect of the above problem is addressed by a waste water piping system (5) including: a non-vertical waste water pipe (22), such as a sewage pipe, that may include a liquid trap seal (25); an adapter (200); and an air valve (1) for equalizing waste water pipe under-pressures exceeding a predetermined threshold under-pressure value while preventing odours from escaping the waste water piping system (5); the air valve (1) comprising: a valve housing (100) having: a housing body (105); an air valve input (110); and an air valve output (120); wherein said housing body (105) is positioned between the air valve input (110) and the air valve output (120), said housing body (105) forming a channel for fluidly connecting the air valve input (110) with the air valve output (120); wherein the valve housing (100) further comprises: a channel part (180) attached to the air valve input (110); a valve seat (140) arranged at said air valve input (110), surrounding an entry from the first channel part (180) to said housing body (105); and a movable valve member (131) movably arranged inside the housing body (105), said movable valve member (131) having; a valve member surface (133) facing the channel part (180) and the valve seat (140), and wherein the air valve (1), in operation, is capable of switching between a first state and a second state dependent on a pressure difference (ΔΡ) between an ambient first pressure level (PI), and a waste water piping system second pressure level (P2), wherein the movable valve member (131) is adapted to rest sealingly against the valve seat (140) when the air valve (1) is in the first state so as to prevent said odours from leaving the housing body (105), and wherein the movable member (131) is adapted to be positioned in the housing body (105) away from the valve seat (140) when the air valve (1) is in the second state, permitting ambient air to enter the housing body (105) so as to equalize waste water pipe under-pressure when said pressure difference (ΔΡ) exceeds the predetermined threshold value; and wherein a cross-section of the air valve output (120) forms a first virtual flat plane (A) so that, when the air valve (1) is in the second state, said ambient air flows in an output average flow direction (MA) substantially perpendicular to the first virtual flat plane (A); and wherein the valve seat (140) defines a second virtual flat plane (B), and wherein the first virtual flat plane (A) is arranged at a first angle (a) in relation to the second virtual flat plane (B), wherein the first angle (a) has a value in the range from 45 to 135 degrees; an wherein said air valve output (120) is connected, via said adapter (200), to an end portion

(22A) of said non-vertical waste water pipe (22) so that said air valve (1) is mounted outside of a vertical wall (26) of a building (10).

This solution advantageously enables mounting the air valve outdoors while also enabling an efficient equalizing of waste water pipe under-pressures. The mounting of the air valve outdoors renders a reduction of space requirements indoors in the building wherein the waste water piping system is located. Moreover, the design of the air valve and the connection of the air valve, via said adapter, to an end portion of said non-vertical waste water pipe renders efficient equalizing of waste water pipe under-pressures since ambient air can flow from the air valve input into the non-vertical waste water pipe with a minimum of air flow direction changes.

A state of the art air valve disclosed by US209975 Al includes an air valve having a chamber and a vertically positioned pipe, the vertically positioned pipe connecting with a horizontally positioned waste water pipe. The lower part of the disclosed air valve chamber has an opening for admitting air up into the chamber, so that the admitted air can flow sideways to said vertically positioned pipe, and then vertically downwards through the vertically positioned pipe, and thereafter the admitted air can make yet another 90 degree bend to finally flow in a horizontal direction in the horizontally positioned waste water pipe. Thus, whereas the state of the art air valve disclosed by US209975 Al inherently includes a vertically positioned pipe between the state of the art air valve and the state of the art horizontally positioned waste water pipe, the above defined solution advantageously eliminates the vertically positioned pipe, rendering a less bulky design while also enabling ambient air to flow from the air valve input into a non-vertical waste water pipe with a minimum of air flow direction changes.

In the above waste water piping system (5), said adapter (200) may be shaped such that when the air valve (1) is in the second state, said ambient air flows in said average flow direction perpendicular to the first virtual flat plane (A, A') through said adapter and into said non-vertical waste water pipe (22).

In the above waste water piping system (5), said air valve (1) and said adapter (200) are shaped and assembled such that when the air valve (1) is in the second state, said ambient air flows through said air valve input (110) into said air valve (1) in an input average flow direction (MC) and thereafter said ambient air flows through said air valve (1) and through said adapter (200) so as to enter into said non-vertical waste water pipe (22) in said output average flow direction (MA) rendering a change of average flow direction, said change of average flow direction being less than 180 degrees, said change of average flow direction being the angular difference between said input average flow direction and said output average flow direction.

In the above waste water piping system (5), said change of average flow direction may be less than 180 degrees.

In the above waste water piping system (5) said change of average flow direction may be less than 135 degrees.

In the above waste water piping system (5) said change of average flow direction may be at least 45 degrees.

In the above waste water piping system said non-vertical waste water pipe (22) may have a direction of elongation (E ₂₂ ) along parallel opposing internal side walls, and said air valve output (120) is connected, via said adapter (200), to said end portion of said non-vertical waste water pipe (22) so that the plane (B) of said valve seat (140) is arranged at a predetermined angle (w) in relation to said direction of elongation (E ₂₂ ), said predetermined angle (w) having a value in a range between -45 degrees to +45 degrees.

In the above waste water piping system, said non-vertical waste water pipe (22) may run in between a ceiling (27) of a lower level living space in a building and a floor structure (20) which may carry a plurality of waste water generators (21) connected to said waste water pipe (22).

I n the above waste water piping system, said non-vertical waste water pipe (22) may be arranged at an inclination angle (v) in relation to a horizontal direction (x) so that waste water entering the waste water pipe (22) will, due to gravitational force (FG), flow towards a waste water conduit (23) to which said non-vertical waste water pipe (22) is connected, thereby enabling delivery of waste water to a waste water outlet (24).

I n the above waste water piping system, said inclination angle (v) may be smaller than 10 degrees.

I n the above waste water piping system, said inclination angle (v) may be smaller than 5,7 degrees.

I n the above waste water piping system, said non-vertical waste water pipe end portion (22A), may have an interior pipe surface, said adapter (200) having a protruding part (200A) being inserted into said pipe end portion (22A) and attached to the interior of the waste water pipe (22).

I n the above waste water piping system, said non-vertical waste water pipe (22), may have an exterior pipe surface; said adapter (200) having a protruding part (200A) adapted to enclose said exterior pipe surface, and adapted to be attached to at least a part of the exterior pipe surface. In the above waste water piping system, at least one sealing element may be provided between the protruding part (200A) of the adapter and the non-vertical waste water pipe end portion (22A) so as to prevent odours from escaping the waste water piping system (5).

In the above waste water piping system, said at least one sealing element comprises at least one flexible ridge (206) for sealing between the protruding part (200A) of the adapter (200) and the waste water pipe surface.

According to an aspect, there is provided an air valve (1) for equalizing waste water pipe under-pressures exceeding a predetermined threshold under-pressure value while preventing odours from escaping a waste water piping system (5); the air valve (1) comprising: a valve housing (100) having: a housing body (105); an air valve input (110); and an air valve output (120) for connection to a non-vertical waste water pipe

(22), such as a sewage pipe, that may include a liquid trap seal (25); wherein said housing body (105) is positioned between the air valve input (110) and the air valve output (120), said housing body (105) forming a channel for fluidly connecting the air valve input (110) with the air valve output (120); wherein the valve housing (100) further comprises: a channel part (180) attached to the air valve input (110); a valve seat (140) arranged at said air valve input (110), surrounding an entry from the first channel part (180) to said housing body (105); and a movable valve member (131) movably arranged inside the housing body (105), said movable valve member (131) having; a valve member surface (133) facing the channel part (180) and the valve seat (140), and wherein the air valve (1), in operation, is capable of switching between a first state and a second state dependent on a pressure difference (ΔΡ) between an ambient first pressure level (PI), and a waste water piping system second pressure level (P2), wherein the movable valve member (131) is adapted to rest sealingly against the valve seat (140) when the air valve (1) is in the first state so as to prevent said odours from leaving the housing body (105), and wherein the movable member (131) is adapted to be positioned in the housing body (105) away from the valve seat (140) when the air valve (1) is in the second state, permitting ambient air to enter the housing body (105) so as to equalize waste water pipe under-pressure when said pressure difference (ΔΡ) exceeds the predetermined threshold value; and wherein a cross-section of the air valve output (120) forms a first virtual flat plane (A) so that, when the air valve (1) is in the second state, said ambient air flows in an output average flow direction (MA) substantially perpendicular to the first virtual flat plane (A); and wherein the valve seat (140) defines a second virtual flat plane (B), and wherein the first virtual flat plane (A) is arranged at a first angle (a) in relation to the second virtual flat plane (B), wherein the first angle (a) has a value in the range from 45 to 135 degrees; an wherein said air valve output (120) is, in a releasable manner, connectable, via an adapter (200), to an end portion (22A) of said non-vertical waste water pipe (22) so that said air valve (1) is mountable outside of a vertical wall (26) of a building (10). I n the above air valve (1), said adapter (200) may be shaped such that when the air valve (1) is in the second state, said ambient air flows in said average flow direction perpendicular to the first virtual flat plane (A, A') through said adapter and into said non-vertical waste water pipe (22).

I n the above air valve (1), said air valve (1) and said adapter (200) may be shaped and assembled such that when the air valve (1) is in the second state, said ambient air flows through said air valve input (110) into said air valve (1) in an input average flow direction (MC) and thereafter said ambient air flows through said air valve (1) and through said adapter (200) so as to enter into said non-vertical waste water pipe (22) in said output average flow direction (MA) rendering a change of average flow direction, said change of average flow direction being less than 180 degrees, said change of average flow direction being the angular difference between said input average flow direction and said output average flow direction.

I n the above air valve (1), said change of average flow direction may be at least 45 degrees, and said change of average flow direction is less than 135 degrees.

I n the above air valve (1), said air valve output (120) may be connected, via said adapter (200), to said end portion of said non-vertical waste water pipe (22) so that the plane (B) of said valve seat (140) is arranged at a predetermined angle (w) in relation to a direction of elongation ( E22) of said non-vertical waste water pipe (22), said predetermined angle (w) having a value in a range between -45 degrees to +45 degrees. In the above air valve (1), said adapter (200) may have a protruding part (200A) being insertable into said pipe end portion (22A) and attachable to an interior surface of the waste water pipe (22).

In the above air valve (1), said adapter (200) may have a protruding part (200A) adapted to enclose an exterior pipe surface, said protruding part (200A) being adapted to be attachable to at least a part of the exterior pipe surface.

In the above air valve (1), said adapter (200) may include at least one sealing element adapted to be placed between the protruding part (200A) of the adapter and the non- vertical waste water pipe end portion (22A) so as to prevent odours from escaping a waste water piping system (5).

In the above air valve (1), said at least one sealing element may comprise at least one flexible ridge (206) for sealing between the protruding part (200A) of the adapter (200) and the waste water pipe surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 illustrates a building with a waste water piping system.

Fig. 2 illustrates a cross section of a side view of an air valve in a first state according to one aspect of the invention. Fig. 3 illustrates a side view of an air valve according to one aspect of the invention.

Fig.4 illustrates a cross section of a side view of an air valve in a second state according to one aspect of the invention.

Fig. 5a illustrates a side view of a movable valve member according to one aspect of the invention. Fig. 5b illustrates a top view of a movable valve member according to one aspect of the invention. Fig. 5c illustrates an exploded view of an air valve according to one aspect of the invention.

Fig. 6 illustrates a section of the air valve according to one aspect of the invention.

Fig. 7a illustrates a side view of a supporting element according to one aspect of the invention. Fig. 7b illustrates a top view of a supporting element according to one aspect of the invention.

Fig. 8 illustrates a view of an air valve according to one aspect of the invention

Fig. 9 illustrates a cross section of a front view of an air valve according to one aspect of the invention Fig. lOa-b illustrate a bottom view of an air valve and the supporting members of the air valve according to one aspect of the invention

Fig. lla-b illustrate a bottom view of an air valve and the supporting members of the air valve according to one aspect of the invention

Fig. 12A illustrates one aspect of the air valve 1. Fig. 12B illustrates an example of an adapter 200 when the air valve is mounted on the outside of a vertical wall 26.

For the purpose of this document, the term "valve" means any device that shuts off, starts, regulates, or controls the flow of a fluid.

The coordinate systems added to the figures are intended to clarify the angles of the views of the figures. The orientation of the coordinate system for each figure corresponds to the orientation of each respective figure.

Figure 1 illustrates an embodiment of a waste water piping system 5 for use in a multi-storey building 10. The building is schematically illustrated as having several floor structures 20 and a wall 26. The wall 26 may be a wall separating the interior space of the building from an exterior space. Thus, the wall 26 may be a wall separating the interior space of the building from the outside. A floor structure 20 of the building may comprise a waste water pipe 22 to which a number of schematically illustrated waste water generators 21 are connected. Each waste water generator 21 comprises a water seal 25. The waste water generators 21 could for example be a wash basin, a water closet, a shower outlet etc. The water seals 25 may prevent odour from escaping the waste water piping system 5 into the interior of the building.

The waste water pipe 22 is connected to a waste water conduit 23, which may be adapted to collect waste water from a plurality of waste water pipes 22 and for delivering the collected waste water to a waste water outlet 24.

The waste water pipe 22 may be mounted in the floor structure 20 between a ceiling 27 of a lower level living space in the building and a floor surface 28 of a higher level living space in the building. The waste water pipe 22 may run in the floor structure 20 which may carry a plurality of waste water generators 21.

The waste water in the waste water piping system 5 will be affected by gravitation. Hence, a gravitational force will act, in the direction of arrow F _G in Figure 1, on the waste water, thus leading to transportation of the waste water in the waste water conduit 23 in the direction of arrow F _G in Figure 1.

I n order to achieve a flow of waste water in the waste water pipe 22 from the waste water generators 21 towards the waste water conduit 23, the waste water pipe 22 is arranged at an angle v in relation to a horizontal direction x so that the waste water pipe 22 connects to the waste water conduit 23 at a vertically lower level than the level at which the waste water generators 21 are connected to the waste water pipe 22. I n other words, the waste water pipe 22 may have a downward inclination towards the waste water conduit 23. Hence, waste water entering the waste water pipe 22 will, due to the gravitational force F _G , flow towards the waste water conduit 23. The angle v may be any angular value smaller than 10 degrees.

The coordinate system having a horizontal axis x and a vertical axis y, as shown in figurel is intended to clarify the angles. Thus, from Figure 1 it can be deduced that the waste water conduit 23 may be mounted in a vertical direction of elongation. The waste water pipe 22 is arranged at the angle v in relation to the horizontal direction. Thus, the waste water pipe 22, being arranged at the angle v, may be arranged at a non-vertical and non-horizontal direction of inclination.

The angle v may selected so that the waste water pipe 22 has an elevational drop of less than 10%, i.e. less than 10 centimetres per meter. A 10% elevational drop corresponds to 5,7 degrees. Thus the angle v may be 5,7 degrees, or less than 5,7 degrees. Thus, the waste water pipe 22 may be mounted so that a one meter length of the waste water pipe 22 drops 10 centimetres, or less 10 centimetres. According to another example, the waste water pipe 22 may be mounted at an inclination of less than 5%, i.e. so that a one meter length of the waste water pipe 22 drops 5 centimetres, or less 5 centimetres. A 5% elevational drop corresponds to 2,9 degrees. Thus the angle v may be 2,9 degrees, or less than 2,9 degrees.

The waste water pipe 22 may run in between a ceiling 27 of a lower level living space in the building and the floor structure 20 which may carry a plurality of waste water generators 21.

The waste water pipe 22 and the waste water conduit 23 have a second pressure level P2. The second pressure level P2 may vary, for example due to a sudden appearance of a large amount of waste water being delivered from one or several of the waste water generators 21. In particular an under-pressure, in terms of the second pressure level P2 deviating from a first pressure level PI, which is the ambient pressure level of the environment, may develop when one or several waste water generators 21 deliver waste water simultaneously such that the second pressure level P2 in the waste water pipe 22 decreases when the pipe 22 empties into the conduit 23. In other words, when waste water is transported in the waste water pipe 22 or in the waste water conduit 23, an under-pressure may be created behind the waste water. This under-pressure may cause the water seals 25 of the waste water generators 21 to be partly or completely emptied. A water seal 25 needs to be filled with water in order to prevent odours from escaping. Hence, the under-pressure caused by the waste water running in the waste water pipe 22 and/or the waste water conduit 23 has to be dealt with in order to assure that the water seals 25 of the waste water generators 21 are kept intact.

The under-pressure in the waste water pipe 22 and the waste water conduit 23 may be alleviated by providing an air valve 1 for equalizing waste water pipe under-pressures and preventing the water seals 25 of the waste water generators 21 to be affected by the under- pressure in the waste water system 5. As shown in Figure 1 the air valve 1 may be attached to an end portion 22A the waste water pipe 22. The air valve 1 is arranged to open when the pressure difference ΔΡ between an ambient first pressure level PI, and a waste water piping system 5 second pressure level P2 reaches a certain predefined reference level Rl. The predefined reference level Rl may be varied order to fulfil the requirements of a specific waste water piping system 5. The air valves 1 are constructed so that the air valve 1 opens at the predefined reference level Rl.

When the air valve 1 opens, that is, when the pressure difference ΔΡ between an ambient first pressure level PI, and a waste water piping system 5 second pressure level P2 reaches a predefined reference level Rl, surrounding air is allowed to flow into the waste water piping system 5 and the under-pressure in the system 5 is equalised. The predefined reference level Rl is set at a level so that the air valve 1 will open before the water seals of the waste water generators 21 are affected. Hence, by connecting air valves 1 to the waste water piping system 5, the water seals 25 of the waste water generators 21 in the system 5 are not affected by an under-pressure created by for example at least one of the waste water generators 21.

The air valves 1 may be attached to the exterior of the building. According to one aspect, the air valve is attached to an outer wall of the building. Since the air valve is attachable to a vertical surface, the roof area will not have to be utilized for air valves. Hence, the roof area may be used for other purposes such as a socializing area as illustrated in figure 1.

Figure 2 illustrates an aspect of an air valve 1 for equalizing waste water pipe underpressures while preventing odours from escaping a waste water piping system 5. The air valve 1 is illustrated in a cross sectional side view.

The air valve 1 comprises a valve housing 100 having a housing body 105, an air valve input 110, an air valve output 120 and a channel part 180 attached to the air valve input 110. The housing body 105 is positioned between the air valve input 110 and the air valve output 120, forming a channel for fluidly connecting the air valve input 110 with the air valve output 120. The air valve output 120 is arranged to be connected to a waste water pipe system 5 such as a sewage system. The air valve output 120 is preferably arranged to be connected to a waste water pipe 22.

A valve seat 140 is arranged at said air valve input 110, surrounding an entry from the first channel part 180 to said housing body 105. A movable valve member 131 is movably arranged inside the housing body 105, said movable valve member 131 having a valve member surface 133 facing the channel part 180 and the valve seat 140. The air valve is capable of switching between a first state and a second state dependent on a pressure difference ΔΡ between an ambient first pressure level PI, and a waste water piping system second pressure level P2. When the pressure difference ΔΡ reaches a certain predefined reference level R|, the air valve 1 opens, or in other words, switches from a first state to a second state. When the pressure difference ΔΡ goes below the predefined reference level R|, the air valve closes, or in other words, switches from a second state to a first state

When the air valve 1 is in the first state, which is illustrated in figure 2, the movable valve member 131 is adapted to rest sealingly against the valve seat 140. Hence, in the first state, odours are prevented from leaving the housing body 105. The valve seat 140 may be a ring shaped edge constructed in an optimal way in order to be able to form an air tight seal together with the movable valve member 131, see figure 6.

In the second state, the movable member 131 is adapted to be positioned in the housing body 105 away from the valve seat 140, permitting ambient air to enter the housing body 105 so as to equalize waste water pipe under-pressures.

A virtual plane A defined by the orientation of the air valve output 120 is arranged at a first angle a in relation to a virtual plane B defined by the orientation of the valve seat 140.

The first angle a illustrated in this aspect is 90 degrees. However, the first angle a may vary. According to one aspect not illustrated, the air valve 1 is constructed with a first angle a between plane A and B in the air valve 1 is within a range of 45 to 135 degrees.

According to one aspect, the air valve 1 is constructed so that the direction of the main air flow MC in the channel part 180 and the direction of the main air flow MA in the adapter part 200 is at an angle of 45 to 135 degrees in relation to each other when the air valve is in a second state permitting ambient air to flow into the air valve 1. The air flow at different positions through the air valve 1 may vary, but the main air flow will have a certain direction, at least in the channel part 180 and in the adapter part 200.

The air valve output 120 is arranged to be mounted on a pipe 22 in a waste water system 5, which pipe 22 has a centre line 6 arranged in angle of -45 to +45 degrees in relation to the virtual plane B defined by the orientation of the valve seat 140. The air valve output 120 may be defined as a circular surface connectable to an adapter part 200 or alternatively, the air valve output 120 may be defined as a part of a channel forming the outlet of the housing body 105. Hence, the air valve output 120 may be arranged at an angle in relation to a normal to the virtual plane B.

An adapter part 200, which will be further described in figure 6 and 7, is attachable to the valve output 120.

The valve member surface 133 facing the channel part 180 and the valve seat 140 corresponds to the dimension and shape of the valve seat 140. According to one aspect, both the valve member surface 133 and the valve seat 140 are circular.

The valve member surface 133 and the valve seat 140 are constructed so as to form a seal, preventing odours from escaping the waste water system 5 when the air valve 1 is in the first state. The valve member surface 133 may according to one aspect be constructed in a flexible material such as rubber and the valve seat 140 may be constructed in a hard material such as plastic, metal or ceramic. Alternatively, the valve seat 140 may be constructed in a flexible material such as rubber and the valve member surface may be constructed in a hard material, such as plastic or metal.

The channel part 180 has an inner surface 190. The movable valve member 131, which is further described in relation to figure 5a and 5b, comprises a head part 142 and a protruding element 143. The head part 142 is movably arranged inside the housing body 105 and the protruding element 143 is slidably arranged in a supporting structure 155. The supporting structure 155 is arranged in the channel part 180. The supporting structure 155 is positioned within the channel part 180 by means of at least three supporting members 195 attached to the inner surface 190 of the channel part 180. See figure 6a and 6b for further details regarding the supporting members 195.

In order to achieve an optimal function of the air valve 1, the movable valve member 131 should be arranged to be able move in a vertical direction along an axis y. The head part 142 of the movable valve member 131 should be arranged in a horizontal direction x, and hence the virtual plane B defined by the orientation of the valve seat 140 may be aligned with a horizontal direction x. When the head part of the movable valve member 131 is arranged in a horizontal direction x, an optimal seal between the valve member surface 133 and the valve seat 140 is achieved. In addition, an optimal movement of the movable valve member 131 in the supporting structure 155 and in the housing body 105 may be achieved, since when arranged in this direction, a minimal, or reduced, friction of the movable valve member 131 and the supporting structure 155 as the movable valve member 131 glides in the supporting structure is achieved.

In order to construct the air valve 1 with an optimal air flow and sealing function when mounted to a waste water pipe 22, the first angle a may be adjusted to the third angle v of the waste water pipe 22 to which the air valve 1 is to be mounted so that the movable valve member 131 is still arranged to move in a vertical direction y. This construction of the air valve 1 may be achieved by the design of the air valve 1 or by the design of the adapter part 200. The channel part 180 is attached to the inlet 110 of the air valve 1 in order to improve the air flow through the air valve 1. Tests have shown that the flow of air through the air valve 1 can be optimized by constructing the channel part 180 with a certain length L. According to one aspect, the length L of the channel part 180 corresponds to 30-70 % of the radius of the circular valve member surface 133. According to one aspect, the length L of the channel part 180 is 35-45 % of the radius of the circular valve member surface 133.

According to one aspect the channel part 180 has a funnel shaped opening 135. Air flow tests have shown that a funnel shaped opening 135 improves the flow of air through the air valve 5 when the air valve is in the second state. The dimensions of the funnel shaped opening 135 may vary. Figure 3 illustrates a side view of one aspect of an air valve 1 for equalizing waste water pipe under-pressures while preventing odours from escaping a waste water piping system 5.

The air valve 1 comprises a valve housing 100 having a housing body 105 and a channel part 180. The channel part 180 has a certain length L. I n addition, an adapter part 200 is illustrated. The adapter part 200 is connected to the air valve 1. The adapter part 200 is constructed in order to be able to attach the air valve 1 to a waste water pipe 22. The dimension of the adapter part 200 is chosen for a specific installation. A specific adapter part 200 is chosen for each installation in order to fit waste water pipes 22 of different dimension. The adapter part 200 may be constructed in order to be attached to the interior of the waste water pipe 22, as illustrated in figure 2. According to one aspect, the adapter part 200 may be constructed in order to be attached the exterior of the waste water pipe 22.

Figure 4 illustrates a cross sectional side view of an air valve 1 in a second state. The pressure difference ΔΡ between an ambient first pressure level PI, and a waste water piping system second pressure level P2 is above a certain predefined reference level R| and hence, the movable valve member 131 is in the second state wherein the movable valve member 131 is positioned in the housing body 105 away from the valve seat 140. Ambient air is permitted to enter the housing body 105 so as to equalize waste water pipe underpressures. The air flow of ambient air in the air valve 1 is schematically illustrated by arrows. Figure 5a and 5b schematically illustrates the movable valve member 131 seen from two different directions. The coordinate systems illustrated in the bottom left corner illustrates the direction from which figure 5a is viewed, and the coordinate system illustrated in the bottom right corner illustrates the direction from which figure 5b is viewed. Figure 5a illustrates a side view of the movable valve member 131 and figure b illustrates a bottom view of the movable valve member 131. The movable valve member 131 comprises a head part 142 and a protruding element 143. According to this aspect, the head part 142 is circular. The head part 142 is according to one aspect constructed by a number of layers. One first layer 136 is arranged at the top of the head part 142. This first layer 136 is formed out of a hard material, such as plastic or metal. According to one aspect, the first layer 136 comprises protruding means facing a second layer 133. The protruding means may be arranged along the outer edge of the first layer 136. The second layer 133 is according to one aspect a flexible layer made of a material such as rubber. This flexible second layer 133 forms the valve member surface 133. The valve member surface is arranged to form a seal together with the valve seat 140 when the air valve 1 is in the first state. The radius of the second layer 133 corresponds according to one aspect to the radius of the first layer 136. The head part 142 comprises a third layer 137. The third layer 137 is formed out of a hard material, such as plastic or metal. The third layer 137 is arranged to stabilize the second layer 133. The third layer has a radius which is smaller than the radius of the second layer 133. The bottom view of the movable valve member 131 is illustrated in figure 5b where the valve member surface 133 is disclosed. The valve member surface 133 is according to this embodiment ring shaped and the dimension of the valve member surface 133 is formed in order to fit the valve seat 140 so that the valve member surface 133 and the valve seat 140 can form a seal preventing odours from escaping from the air valve 1 when the air valve 1 is in a first state. According to one aspect, the valve member surface 133 is a ring shaped surface, as illustrated in figure 5b.

Figure 5c illustrates an exploded side view of the air valve 1 and the movable valve member 131.

The dimension and the weight of the movable valve member 131 affects the seize of the pressure difference ΔΡ between an ambient first pressure level PI and a waste water piping system second pressure level P2 for which the air valve 1 switches between a first state and a second state. I n the first state, the protruding element 143 is situated inside the supporting structure 155, while the head part 142 with the valve member surface 133 arranged on the bottom of the head part 142, is sealingly resting against the valve seat 140 so as to prevent odours from leaving the housing body 105. When the pressure difference ΔΡ between an ambient first pressure level PI and a waste water piping system second pressure level P2 reaches a certain predefined reference value R|, the movable valve member 131 moves upwards, in a vertical direction perpendicular to the virtual plane B. The protruding member 143 glides or slides in the supporting structure 155, and the head part 142 moves upwards in the housing body 105, permitting ambient air to enter the air valve 1. According to one aspect, the housing body 105 comprises guiding means G which prevents the head part 142 to be displaced in the housing body 105.

The air valve 1 will remain open in a second state until the pressure difference ΔΡ between an ambient first pressure level PI and a waste water piping system second pressure level P2 falls below a certain predetermined reference value R|. When the pressure difference ΔΡ falls below a certain predetermined reference value R|, the protruding part 143 of the movable valve member 131 slides down in the supporting structure 155 until the head part 142 and especially the valve member surface 133 reaches the valve seat 140 and the valve member surface 133 and the valve seat 140 form a seal. Figure 6 illustrates a top view of the valve seat 140 of the air valve 1 which valve seat 140 together with the valve member surface 133 form a seal when the air valve 1 is in the first state. The valve seat 140 may be a ridge formed in a hard material such as plastic or metal. The shape of the valve seat 140 corresponds to the shape of the valve member surface 133.

Figure 7a and 7b schematically illustrates the supporting member 195 seen from two different directions. The coordinate systems illustrated in the bottom left corner illustrates the direction from which figure 7a is viewed, and the coordinate system illustrated in the bottom right corner illustrates the direction from which figure 7b is viewed.

As illustrated in figure 7a and 7b, the supporting elements 195 are thin wing like elements with four sides. SI is arranged to be attached to the supporting structure 255 of the air valve 1, S2 is arranged to be pointing towards the valve member surface 133 of the air valve 1, S3 is arranged to be attached to the inner wall 190 of the channel part 180 of the air valve 1.

S2 has a recess arranged to receive the third layer 137 of the valve member 131. S4 is according to the illustrated embodiment curved. Tests have shown that this design of the side S4 improves the airflow in the air valve 1 in comparison with supporting members without the curve shaped form.

Alternative designs of the supporting member 195 are possible. S4 may have different shapes, such as being a straight line or having an uneven shape. According to one aspect, the supporting member 195 is not be solid, but may comprise holes of different shapes. I n addition, the design of the support elements in the same air valve 1 may vary in order to achieve an optimal air flow through the air valve 1 and at the same time form a robust construction.

Figure 8 illustrates the air valve 1 seen from a different view compared with the previous figures. The coordinate system illustrates the direction of the view of the air valve 1 in figure 8. The adapter part 200 in figure 8 is adapted to be inserted into a waste water pipe 22, and hence comprises ridges 206 in order to seal the connection between the air valve 1 and the waste water pipe 22. The adapter part 200 is arranged to be attached to a substantially vertical building element such as a wall. The adapter part 200 comprises protrusions 205 with openings 210 wherein each opening 210 is arranged to receive an attachment device such as a screw. Alternatively, the adapter part may comprise alternative fasting means.

The adapter part may be exchanged in order to fit to a certain dimension of a waste water pipe 22.

According to one example, the adapter part 200 is adapted to enclose a waste water pipe 22. According to this embodiment, sealing elements, such as ridges or similar constructions, will be arranged on the interior of the adapter part 200 (not illustrated)

Figure 9 illustrates a cross section of a front view of the air valve 1 and the adapter part 200. The coordinate system illustrates the direction of the view of the air valve 1 and the adapter part 200. The air valve 1 is in a second state wherein air is permitted to flow into the housing body 105.

Figure 10a and figure 10b illustrate bottom views of the air valve 1 and the adapter part 200. The coordinate system illustrates the direction of the view of the air valve 1 and the adapter part 200. The supporting structure 155 is positioned within the channel part 180 by means of four supporting members 195 attached to the inner surface 190 of the channel part 180. The supporting members 195 are arranged in a radial direction from the supporting structure 155 to the inner surface 190 of the channel part 180. The second angle β between each supporting member 195 seen in a virtual plane B defined by the orientation of the valve seat 140 (see figure 2), is equal. Hence, the supporting members are distributed evenly around the supporting member 155. In the illustrated aspect, the second angle β is 90 degrees.

In the illustrated aspect in figure 10a, two of the supporting members 195 are arranged in a direction D, wherein the direction D is at an angle of 45 degrees in relation to a virtual plane A defined by the orientation of the air valve output 120.

By orienting the supporting members 195 in a different angle, the air flow through the air valve 1 is affected. The aspect illustrated in figure 10a creates a good air flow through the air valve 1.

In the illustrated aspect of figure 10b, two of the supporting members 195 are arranged in a direction C, wherein the direction C is perpendicular to a virtual plane A defined by the orientation of the air valve output 120. By orienting the supporting members in this illustrated manner, an even better air flow is achieved through the air valve 1 when the air valve is in a second state compared to the aspect illustrated in figure 10a.

Figure lla-llc illustrates bottom views of the air valve 1 and the adapter part 200. The coordinate system on the page illustrates the direction of the view of the air valve 1 and the adapter part 200.

The supporting structure 155 is positioned within the channel part 180 by means of three supporting members 195 attached to the inner surface 190 of the channel part 180. The supporting members 195 are arranged in a radial direction from the supporting structure 155 to the inner surface 190 of the channel part 180. The second angle β between each supporting member 195 seen in a virtual plane B defined by the orientation of the valve seat 140 (see figure 2), is equal. Hence, the supporting members are distributed evenly around the supporting member 155. In the illustrated aspect, the second angle β is 120 degrees.

In the aspect illustrated in figure 11a, one of the supporting members 195 is arranged in a direction E, wherein the direction E is in a direction parallel to a virtual plane A defined by the orientation of the air valve output 120. This positioning of the three supporting members 195 is position 1. Tests have shown that a construction of an air valve 1 where only three supporting members 195 are used improved the flow through the air valve 1 when the air valve 1 is in a second state, compared to a construction where four supporting members 195 are used. By arranging one of the supporting members 195 in a direction E, a good air flow through the air valve 1 is achieved. In addition, the air valve 1 achieves a robust construction wherein the movable valve member 131 is supported in an appropriate way by the supporting structure 155.

In the illustrated aspects of figure lib and 11c, the air valve 1 comprises three supporting members 195. One of the supporting members 195 is arranged in a direction C, wherein the direction C is in a direction perpendicular to a virtual plane A defined by the orientation of the air valve output 120.

According to the aspect illustrated in figure lib, one of the supporting members 195 is arranged in a direction C, pointing in a direction from the supporting structure 155 away from the air valve output 120. This positioning of the three supporting members 195 is position 2. This orientation of the supporting members 195 achieves a better air flow through the air valve 1 compared to the embodiment disclosed in figure 11a.

According to another aspect illustrated in figure 11c, one of the supporting members 195 is arranged in a direction C, from the supporting structure 155 in a direction C towards the air valve output 120. This positioning of the three supporting members 195 is position 3. This orientation of the supporting member achieves an even better air flow through the air valve 1 compared to the embodiments disclosed in figure 11a and lib.

Figure 12A illustrates one aspect of the air valve 1 and the adapter part 200. In the illustrated aspect, the adapter part 200 has been adjusted in order to align with a direction of a waste water pipe 22 and at the same time the orientation of the air valve 1 is optimal, with the valve surface 133 in a horizontal direction, allowing the movable valve member 131 to move in a strictly vertical direction y for optimal movement and sealing abilities. As shown in Fig. 12A, the Figure 12A version of adapter 200 provides a bend by an angle w. In this manner the plane B of the valve seat (140) may be positioned horizontally while the non-vertical waste water pipe 22, having a direction of elongation E22, may be arranged at a predetermined angle w, v in relation to said direction of elongation (E22). Thus, the non- vertical waste water pipe (22) has a direction of elongation (E22) along parallel opposing internal side walls, and the air valve output (120) is connected, via said adapter (200), to said end portion of said non-vertical waste water pipe (22) so that the plane (B) of said valve seat (140) is arranged at a predetermined angle (w) in relation to said direction of elongation (E22). The predetermined angle (w) may have a value in a range between -45 degrees to +45 degrees. The angle w equals the angle v when the plane B of the valve seat 140 is positioned horizontally, i.e. when the plane B of the valve seat 140 is parallel with the horizontal axis x, as illustrated in Fig. 12.

Figure 12B illustrates an example of an adapter 200 when the air valve is mounted on the outside of a vertical wall 26. The adapter 200 has a protruding part 200B adapted to enclose an exterior pipe surface 22B, said protruding part 200B being adapted to be attachable to at least a part of the exterior pipe surface 22B.

The adapter 200 may include at least one sealing element adapted to be placed between the protruding part 200B of the adapter and the non-vertical waste water pipe end portion 22B so as to prevent odours from escaping a waste water piping system 5. The sealing element may comprise a glue (not shown). The glue thereby may provide sealing as well as attachment function. As shown in Figure 12A, the at least one sealing element may also comprise at least one flexible ridge 206 for sealing between the protruding part 200A or 200B of the adapter 200 and the waste water pipe surface. Thus, the protruding part 200B, illustrated in figure 12B may have one or several flexible ridge(s) 206 positioned between the interior surface of the protruding part 200B and the exterior pipe surface 22B.

Figure 13 illustrates a diagram showing the air flow through an air valve 1 according to one aspect. The graphs disclose the flow of air through the air valve 1 in a second state in relation to the height of the channel part 180. The graphs represent the measured values for the air flow for the three different positions, position 1, position 2, position 3 of the three supporting members 195 of the air valve, see figure lla-c for two different pressure differences ΔΡ between an ambient first pressure level PI, and a second pressure level P2. As can be seen in figure 13, the air valve 1 with the supporting members 195 in position 3 achieves the best air flow through the air valve 1 when the air valve 1 is open, in the second state.

Further embodiments are described below.

An embodiment 1 includes an air valve (1) for equalizing waste water pipe under-pressures exceeding a predetermined threshold under-pressure value while preventing odours from escaping the waste water piping system comprising: a valve housing (100) having: a housing body (105); an air valve input (110) ; an air valve output (120) for connection to a partly air filled waste water pipe (22), such as a sewage pipe, that may include a liquid trap seal; wherein said housing body (105) is positioned between the air valve input (110) and the air valve output (120), said housing body (105) forming a channel for fluidly connecting the air valve input (110) with the air valve output (120); wherein the valve housing (100) further comprises: a channel part (180) attached to the air valve input (110); a valve seat (140) arranged at said air valve input (110), surrounding an entry from the first channel part (180) to said housing body (105); and a movable valve member (131) movably arranged inside the housing body (105), said movable valve member (131) having; a valve member surface (133) facing the channel part (180) and the valve seat (140), and wherein the air valve (1), in operation, is capable of switching between a first state and a second state dependent on a pressure difference (ΔΡ) between an ambient first pressure level (PI), and a waste water piping system second pressure level (P2), wherein the movable valve member (131) is adapted to rest sealingly against the valve seat (140) when the air valve (1) is in the first state so as to prevent said odours from leaving the housing body (105), and wherein the movable member (131) is adapted to be positioned in the housing body (105) away from the valve seat (140) when the air valve (1) is in the second state, permitting ambient air to enter the housing body (105) so as to equalize waste water pipe under-pressure when said pressure difference (ΔΡ) exceeds the predetermined threshold value.

This solution has the advantageous effect of ensuring the integrity of liquid trap seals in the waste water piping system by equalizing under-pressure that may arise in the waste water pipe thereby also preventing odours from escaping via the liquid trap seal. This is because, when the pressure in the pipe is lower than the ambient pressure, the air valve will allow ambient air to enter so as to equalize the under-pressure, thus preventing the liquid in the liquid trap seal from being sucked away therefrom. If the liquid were sucked away from the liquid trap seal then air and sewer gases from the waste water pipe would be allowed to pass freely into the room where the liquid trap seal was installed.

Moreover, when the air valve output is fitted to an end portion of a waste pipe, the air valve may prevent odours and/or warm and moist air from flowing out from the end portion of the waste pipe. Thus, the provision of such an air valve even makes it possible to terminate such a waste pipe indoors while preventing odours from escaping the waste pipe. The provision of such an air valve also makes it possible to terminate outdoors e.g. in the vicinity of an outdoor entertainment area, such as e.g a balcony or a roof terrace, while preventing odours from affecting the air quality of the outdoor entertainment area. Additionally, the above defined air valve has an advantageously robust design enabling the movable valve member to rest sealingly against the valve seat when the air valve is in the first state so as to prevent said odours from leaving the housing body. Thus, whereas, the air valve of EP 0 867 569 requires at least two valve-seat rings, the above defined air valve enables a simplified design which may require only one valve seat. A reduction from two valve seats to one valve seat may constitute a significant reduction in the physical dimensions of the corresponding sealing area, thus increasing the reliability of the air valve sealing capacity and reducing the risk of leakage.

The pressure difference (ΔΡ) between an ambient pressure level (PI), and a waste water piping system pressure level (P2) constitutes the predetermined threshold under-pressure value at which waste water pipe under-pressures is equalized. When the air valve is operably mounted so that the movable valve member is movable in a vertical direction, the predetermined threshold under-pressure value may be an under-pressure value

corresponding to the weight of the movable valve member (131). In effect, the force required to open the valve may depend on the weight of the movable valve member and on the surface areas of the movable valve member subjected to the ambient pressure level (PI), and the waste water piping system pressure level (P2), respectively. According to embodiments of the air valve, the predetermined threshold under-pressure value may be selected to be a lower pressure value than the under-pressure value required for sucking liquid away from the liquid trap seal. Thus, the predetermined threshold under-pressure value may be selected dependent on the physical dimensions of a liquid trap seal coupled to the water pipe system (5) and the predetermined threshold under-pressure value may be selected dependent on the density of the relevant liquid. The liquid in the liquid trap seal may be e.g. water. According to embodiments of the air valve, the predetermined threshold under-pressure value may be selected to be 150 Pascal. Providing air valve wherein the predetermined threshold under-pressure value is 150 Pascal may be suitable when the under-pressure value required for sucking liquid away from the liquid trap seal is substantially higher than 150 Pascal, such as in a range from 200 Pascal to 600 Pascal. Thus, for example, when the under- pressure value required for sucking liquid away from the liquid trap seal is 500 Pa, and the predetermined threshold under-pressure value is 150 Pascal, there will advantageously be a safety margin of 350 Pa.

Embodiment 2 is an air valve according to embodiment 1, wherein a cross-section of the air valve output (120) forms a first virtual flat plane (A) so that, when the air valve (1) is in the second state, said ambient air flows in an average flow direction substantially perpendicular to the first virtual flat plane (A); and the valve seat (140) defines a second virtual flat plane (B), and wherein the first virtual flat plane (A) is arranged at a first angle (a) in relation to the second virtual flat plane (B), the first angle (a) deviating from 0 degrees. Thus, whereas the air valve of EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a non-vertical waste water pipe.

It is noted that the prior art air valve of EP 0 867 569 has two ring-shaped, horizontal sealing ridges between which ambient air can flow vertically upwards when the prior art air valve is in its open state, and a vertically positioned pipe connector for passing that ambient air vertically downwards when the prior art air valve is in its open state to the substantially vertical waste water pipe. Thus, whereas the air valve of EP 0 867 569 requires the air flow to make a 180 degree change of flow direction when the air valve is in the open state, and whereas the air valve of EP 0 867 569 is adapted for mounting at the upper end of a substantially vertical waste water pipe, the air valve according to this aspect of the invention reduces the required change of flow direction, and it also enables mounting of the inventive air valve at a non-vertical waste water pipe.

In effect, it is noted that whereas the prior art air valve disclosed in EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a substantially horizontal waste water pipe, when the first angle (a) is about 90 degrees. Embodiment 3 is an air valve according to embodiment 2, wherein the first angle (a) has a value in the range from 45 to 135 degrees.

By varying the angle (a), an optimal construction of the air valve in relation to the waste water pipe to which it is to be connected may be achieved, creating an air valve with an optimal air flow. Hence, for a certain required flow of air when the air valve is in the second state, the dimensions of the valve may be kept low, saving space and material costs.

This solution has the advantageous effect of enabling this air valve to be mounted on a substantially horizontal waste water pipe which provides for a robust and space efficient mounting of the air valve. With this air valve, no extra connections or extra piping or bends have to be mounted to an essentially horizontal waste water pipe, and hence, both material and installation time is saved.

Thus, whereas the air valve disclosed in EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a substantially horizontal waste water pipe.

Whereas the prior art air valve of EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the outdoors mounting of the prior art air valve would require either a vertical waste pipe exiting through the roof of the building or the addition of a substantially 90 degree bend of a substantially horizontal waste pipe to obtain the required substantially vertical waste water pipe. By contrast, since the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a substantially horizontal waste water pipe, it enables mounting of the inventive air valve directly on a substantially horizontal waste water pipe that may be allowed to exit the building through a vertical side wall of the building. In this manner the inventive air valve may be mounted at a substantially horizontal waste water pipe and, for physical stability, the body of the air valve may be attached to the vertical side wall of the building. Hence, a very robust construction is achieved.

Thus, when constructing a building comprising a waste water pipe system, material can be saved since the pipes which are arranged essentially horizontally do not have to be provided with vertical connections in order to be able to be fitted with an air valve. In addition, the air valve gives the advantage that for example a roof area may be kept clean since the air valves connected to the waste water system of the building may be attached to the wall instead of the roof, and hence the roof space may be utilized for other purposes. Embodiment 4 is an air valve according to any of embodiments 2 or 3, wherein the first angle (a) is in a range from about 60 degrees to about 90 degrees.

Thus, whereas the air valve disclosed in EP 0 867 569 requires a complete 180 degree change of direction of air flow when the valve is in its open state, the air valve according to this embodiment advantageously only requires the air flow to change its direction of flow by an angle of less than 90 degrees, while providing a robust air valve with a minimum of movable parts and a single valve seat instead of the two valve-seat rings required according to EP 0 867 569. Hence, this embodiment may minimize the risk for fault, while it may achieve an improved flow capacity of the air valve and maintain a minimized number of movable parts. Hence, for a certain required flow of air when the air valve is in the second state, the physical dimensions of the valve may be kept small, thereby saving space while maintaining an excellent air valve function in terms of equalizing waste water pipe under-pressures. The small dimensions of the air valve also renders a lower use of material, such as a plastic material, forming the body of the air valve, thereby rendering low material costs.

Embodiment 5 is an air valve (1) according to embodiment 2 or any preceding embodiment when dependent on embodiment 2, wherein the air valve output (120) is arranged to be mounted on a pipe (22) in a waste water system (5), which pipe (22) has a virtual centre line (6); said virtual centre line (6) being arranged at a predetermined second angle in relation to the second virtual flat plane (B); said predetermined second angle having a value in the range from zero degrees to 45 degrees.

Embodiment 6 is an air valve (1) according to any of embodiments 1-5 wherein an adapter part (200) is attached to the valve output (120), wherein said adapter part (200) is arranged to be attached to a waste water pipe (5). This solution has the advantage that the same air valve may be used for waste water pipes with different dimensions by using an adapter part adapted for a certain waste water pipe. Hence, the construction and the dimensions of the air valve can be kept unchanged but still used for many different waste water pipes, saving manufacturing costs of the air valve. Embodiment 7 is an air valve (1) according to embodiment 6 wherein said adapter part (200) is arranged to be attached to an essentially vertical building element.

This solution provides for a robust mounting of the air valve. The air valve is hence mounted in a robust way directly onto the wall of the building comprising the waste water pipe to which the air valve is attached. This construction provides for a sustainable and robust mounting of the air valve. In addition, the mounted air valve provides for an appealing design of the air valve which does not disturb the environment.

Embodiment 8 is an air valve (1) according to any of embodiments 6-7 wherein the adapter part (200) comprises protrusions (205) with openings (210) wherein each opening (210) is arranged to receive an attachment device such as a screw. The adapter part is according to one aspect attached to a wall of a building with screws which provides for a robust construction which is simple to mount.

Embodiment 9 is an air valve according to any of embodiments 1-8, wherein said channel part (180) comprises a channel part wall, said channel part wall extending in a direction substantially perpendicular to the plane (B) of the valve seat (140) so as to form said channel part (180), and wherein a distance (L) from the plane (B) of the valve seat (140), along a normal to the plane (B), to an end of the channel part wall defines a channel part length (L) of said channel part (180); and wherein said the valve seat (140) encloses said air valve input (110), said air valve input (110) having an inlet cross-sectional area; and wherein the channel part length (L) is longer than 20% of the square root of the inlet cross- sectional area, and the channel part length (L) is shorter than 80% of the square root of the inlet cross-sectional area; or wherein said channel part (180) comprises a channel part wall, said channel part wall extending in a direction substantially perpendicular to the plane (B) of the valve seat (140) so as to form said channel part (180), and wherein a distance (L) from the plane (B) of the valve seat (140), along a normal to the plane (B), to an end of the channel part wall defines a channel part length (L) of said channel part (180); and wherein said the valve seat (140) encloses said air valve input (110), said air valve input (110) having an inlet cross-sectional area; and wherein the channel part length (L) is smaller than the square root of the inlet cross- sectional area; or wherein said channel part (180) comprises a channel part wall, said channel part wall extending in a direction substantially perpendicular to the plane (B) of the valve seat (140) so as to form said channel part (180), and wherein a distance (L) from the plane (B) of the valve seat (140), along a normal to the plane (B), to an end of the channel part wall defines a channel part length (L)of said channel part (180); and wherein said the valve seat (140) encloses said air valve input (110), said air valve input (110) having an inlet cross-sectional area; or wherein said channel part (180) comprises a channel part wall, said channel part wall extending in a direction substantially perpendicular to the plane (B) of the valve seat (140) so as to form said channel part (180), and wherein a distance (L) from the plane (B) of the valve seat (140), along a normal to the plane (B), to an end of the channel part wall defines a channel part length (L) of said channel part (180); and wherein said the valve seat (140) is ring shaped so as to enclose said air valve input (110), said ring shaped valve seat (140) having a valve seat radius; and wherein the channel part length (L) is longer than 30% of said valve seat radius, and the channel part length (L) is shorter than 70% of said valve seat radius.

By providing a channel part attached to the air valve input, where said channel part has a certain length in relation to the air valve inlet cross-sectional area, tests have shown that an optimal flow of ambient air from the environment, in which the air valve is mounted, when the air valve is in a second state, may be received. Hence, for a certain required flow of air when the air valve is in the second state, the dimensions of the valve may be kept low by adapting the length of the channel part, saving space and material costs.

Embodiment 10 is an air valve (1) according to any of embodiments 1-9 wherein said channel part (180) has a funnel shaped opening (135).

A funnel shaped opening of the channel part further improves the flow of ambient air from the environment into the housing body and further into the waste water piping system, when the air valve is in a second state. Hence, for a certain required flow of air from the environment into the waste water piping, when the air valve is in the second state, the dimensions of the valve may be kept low by shaping the channel part as a funnel, saving space and material costs. Embodiment 11 is an air valve (1) according to any of embodiments 1-10, wherein said channel part (180) has an inner surface (190), and wherein said movable valve member (131) comprises a head part (142) and a protruding element (143), which head part (142) is movably arranged inside the housing body (105) and which protruding element (143) is slidably arranged in a supporting structure (155), which supporting structure (155) is arranged in the channel part (180), wherein the supporting structure (155) is positioned within the channel part (180) by means of at least three supporting members (195) attached to the inner surface (190) of the channel part (180).

By using at least three supporting members for supporting and guiding the movable valve member as the states of the air valve changes, a robust construction of the air valve is achieved, and at the same time, an optimal flow of air from the environment into the air valve when the air valve is in the second state is minimally disturbed due to the construction of the air valve parts.

Embodiment 12 is an air valve (1) according to embodiment 11 wherein the supporting members (195) are arranged in a radial direction from said supporting structure (155) to said inner surface (195) and wherein the angle (β) between each supporting member (195) seen in a virtual plane (B) defined by the orientation of the first valve seat 140) is equal.

By distributing each supporting member with an angle (β) between each supporting member, a robust construction which is easy to manufacture is achieved.

Embodiment 13 is an air valve (1) according to any of embodiments 11-12 comprising four supporting members (195) wherein two of the supporting members (195) are arranged in a direction (D), wherein the direction (D) is at an angle of 45 degrees in relation to a virtual plane (A) defined by the orientation of the air valve output (120).

According to one aspect, the placements of the supporting members affect the air flow of air from the environment into the air valve when the air valve is in the second state. By constructing the air valve so that four elongated supporting elements are used, and by placing the elongated supporting elements in a direction D at an angle of 45 degrees in relation to a virtual plane A defined by the orientation of the air valve output 120, an efficient air valve is achieved. Embodiment 14 is an air valve (1) according to any of embodiments 11-13 comprising four supporting members (195) wherein two of the supporting members (195) are arranged in a direction (C), wherein the direction (C) is at a perpendicular angle to a virtual plane (A) defined by the orientation of the air valve output (120). According to one aspect, the placement of the supporting members affects the air flow of air from the environment into the air valve when the air valve is in the second state. By constructing the air valve so that four elongated supporting elements are used, and by placing the elongated supporting elements in a direction C, an optimal flow of air from the environment into the air valve when the air valve is in the second state. Embodiment 15 is an air valve (1) according to any of embodiments 11-12 comprising three supporting members (195), wherein one of the supporting members (195) is arranged in a direction (E), wherein the direction (E) is in a direction parallel to a virtual plane (A) defined by the orientation of the air valve output (120).

By using three supporting members in order to position the supporting structure in the channel part, an optimal flow of ambient air from the environment in which the air valve is mounted when the air valve is in a second state may be received and at the same time, a robust construction of the air valve is achieved. Hence, according to this aspect, for a certain required flow of air when the air valve is in the second state, the dimensions of the valve may be kept low, saving space and material costs. In addition, by using three supporting members, a robust construction of the air valve is received, wherein the positioning structure is kept in its position, supporting the valve member in an adequate manner.

By orienting the supporting members in a certain way, the flow of ambient air from the environment in which the air valve is mounted when the air valve is in a second state may be received. By orienting one of the three supporting members in a direction E, a good flow of air through the air valve is achieved.

Embodiment 16 is an air valve (1) according to any of embodiments 11-12 or 15 wherein one of the supporting members (195) is arranged in a direction (C), wherein the direction (C) is in a direction perpendicular to a virtual plane (A) defined by the orientation of the air valve output (120). According to one aspect, tests have shown that an optimal flow of ambient air from the environment in which the air valve is mounted when the air valve is in a second state may be achieved by placing one of the three supporting members in a direction (C), wherein the direction (C) is in a direction perpendicular to a virtual plane (A) defined by the orientation of the air valve output (120).

Embodiment 17 is a waste water piping system comprising: an air valve (1) according to embodiment 1, and a waste pipe (22) having an open end for permitting ambient air to enter the waste pipe (22) so as to equalize waste water pipe under-pressures. This solution has the advantageous effect of preventing odours by ensuring the integrity of water seals in the waste water piping system by equalizing under-pressure that may arise in the waste water pipe

Embodiment 18 is a waste water piping system according to embodiment 17 wherein: the orientation of the first valve member surface (133) defines a virtual plane B having a normal nt _> .

Embodiment 19 is a waste water piping system according to embodiment 18 wherein: when said ambient air enters the open end, an average direction of air flow is in a direction parallel to the inner walls of said waste pipe, wherein said direction of air flow is at a first predetermined angle ( _v ) in relation to a normal n _b to the virtual plane B, said predetermined angle ( _v ) is an angle smaller than 180 degrees.

This solution has the advantageous effect of preventing odours by ensuring the integrity of water seals in the waste water piping system by equalizing under-pressure that may arise in the waste water pipe. In addition, this air valve may be arranged to be mounted on an essentially horizontal waste water pipe which provides for a robust and space efficient mounting of the air valve. With this air valve, no extra connections or extra piping or bends have to be mounted to an essentially horizontal waste water pipe, and hence, both material and installation time is saved.

The air valve may be attached to for example a wall, and hence, a very robust construction is achieved in comparison with for example an air valve which is arranged to be mounted on a vertical pipe. In the case where the waste water pipe onto which an air valve is to be mounted is horizontal, a bend and further connections have to be created in order to be able to connect an air valve arranged to be mounted on a vertical pipe. When constructing a building comprising a waste water pipe system, material can be saved since the pipes which are arranged essentially horizontally do not have to be provided with vertical connections in order to be able to be fitted with an air valve. In addition, the air valve gives the advantage that for example a roof area may be kept clean since the air valves connected to the waste water system of the building may be attached to the wall instead of the roof, and hence the roof space may be utilized for other purposes. Further, the construction in itself allows the air to move more freely in comparison with for example the air valve disclosed in EP 0 867 569 in which the main air flow has to change direction in an angle of 180 degrees when the air valve is in the second state allowing surrounding air to enter the air valve. With the construction according to this embodiment, the main air flow has to change direction in an angle less than 180 degrees, which improves the flow capacity of the air valve. Hence, for a certain required flow of air when the air valve is in the second state, the dimensions of the valve may be kept low, saving space and material costs.

Embodiment 20 is a waste water piping system according to embodiment 19 wherein predetermined angle (gamma) is in a range of 45-135 degrees. Embodiment 21 is a waste water piping system according to embodiment 19 wherein predetermined angle (gamma) is in a range of 80-100 degrees.

Embodiment 22 is an air valve according to any preceding embodiment, wherein a cross-section of the air valve output (120) forms a first virtual flat plane (A) so that, when the air valve (1) is in the second state, said ambient air flows in an average flow direction substantially perpendicular to the first virtual flat plane (A); and the valve seat (140) defines a second virtual flat plane (B), and wherein the first virtual flat plane (A) is arranged at a first angle (a) in relation to the second virtual flat plane (B) so that the first virtual flat plane (A) is not parallel with the second virtual flat plane (B).

Further examples of air valves are disclosed as examples El to E14 below:

Example El. An air valve (1) for equalizing waste water pipe under-pressures while preventing odours from escaping the waste water piping system comprising: a valve housing (100) having: a housing body (105); an air valve input (110) ; an air valve output (120) for connection to a partly air filled waste water pipe (22), such as a sewage pipe, that may include a liquid trap seal; wherein said housing body (105) is positioned between the air valve input (110) and the air valve output (120), said housing body (105) forming a channel for fluidly connecting the air valve input (110) with the air valve output (120); wherein the valve housing (100) further comprises: a channel part (180) attached to the air valve input (110); a valve seat (140) arranged at said air valve input (110), surrounding an entry from the first channel part (180) to said housing body (105); and a movable valve member (131) movably arranged inside the housing body (105), said movable valve member (131) having; a valve member surface (133) facing the channel part (180) and the valve seat (140), and wherein the air valve (1), in operation, is capable of switching between a first state and a second state dependent on a pressure difference (ΔΡ) between an ambient first pressure level (PI), and a waste water piping system second pressure level (P2), wherein the movable valve member (131) is adapted to rest sealingly against the valve seat (140) when the air valve (1) is in the first state so as to prevent said odours from leaving the housing body (105), and wherein the movable member (131) is adapted to be positioned in the housing body (105) away from the valve seat (140) when the air valve (1) is in the second state, permitting ambient air to enter the housing body (105) so as to equalize waste water pipe under-pressure when said pressure difference (ΔΡ) exceeds the predetermined threshold value, wherein a cross-section of the air valve output (120) forms a first virtual flat plane (A) so that, when the air valve (1) is in the second state, said ambient air flows in an average flow direction substantially perpendicular to the first virtual flat plane (A); and the valve seat (140) defines a second virtual flat plane (B), and wherein the first virtual flat plane (A) is arranged at a first angle (a) in relation to the second virtual flat plane (B), wherein the first angle (a) is defined as the angle starting from the second virtual flat plane (B) and turning in a counter clockwise direction until reaching the first virtual plane A, wherein the first angle (a) has a value in the range from 45 to 135 degrees. Thus, whereas the air valve of EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a non-vertical waste water pipe. The air valve according to the above inventive embodiment improves the flow capacity of the valve.

It is noted that the prior art air valve of EP 0 867 569 has two ring-shaped, horizontal sealing ridges between which ambient air can flow vertically upwards when the prior art air valve is in its open state, and a vertically positioned pipe connector for passing that ambient air vertically downwards when the prior art air valve is in its open state to the substantially vertical waste water pipe. Thus, whereas the air valve of EP 0 867 569 requires the air flow to make a 180 degree change of flow direction when the air valve is in the open state, and whereas the air valve of EP 0 867 569 is adapted for mounting at the upper end of a substantially vertical waste water pipe, the air valve according to this aspect of the invention reduces the required change of flow direction, and it also enables mounting of the inventive air valve at a non-vertical waste water pipe.

In effect, it is noted that whereas the prior art air valve disclosed in EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a substantially horizontal waste water pipe, when the first angle (a) is about 90 degrees.

By varying the angle (a), an optimal construction of the air valve in relation to the waste water pipe to which it is to be connected may be achieved, creating an air valve with an optimal air flow. Hence, for a certain required flow of air when the air valve is in the second state, the dimensions of the valve may be kept low, saving space and material costs.

This solution has the advantageous effect of ensuring the integrity of liquid trap seals in the waste water piping system by equalizing under-pressure that may arise in the waste water pipe thereby also preventing odours from escaping via the liquid trap seal. This is because, when the pressure in the pipe is lower than the ambient pressure, the air valve will allow ambient air to enter so as to equalize the under-pressure, thus preventing the liquid in the liquid trap seal from being sucked away therefrom. If the liquid were sucked away from the liquid trap seal then air and sewer gases from the waste water pipe would be allowed to pass freely into the room where the liquid trap seal was installed. Moreover, when the air valve output is fitted to an end portion of a waste pipe, the air valve may prevent odours and/or warm and moist air from flowing out from the end portion of the waste pipe. Thus, the provision of such an air valve even makes it possible to terminate such a waste pipe indoors while preventing odours from escaping the waste pipe. The provision of such an air valve also makes it possible to terminate outdoors e.g. in the vicinity of an outdoor entertainment area, such as e.g a balcony or a roof terrace, while preventing odours from affecting the air quality of the outdoor entertainment area.

Additionally, the above defined air valve has an advantageously robust design enabling the movable valve member to rest sealingly against the valve seat when the air valve is in the first state so as to prevent said odours from leaving the housing body. Thus, whereas, the air valve of EP 0 867 569 requires at least two valve-seat rings, the above defined air valve enables a simplified design which may require only one valve seat. A reduction from two valve seats to one valve seat may constitute a significant reduction in the physical dimensions of the corresponding sealing area, thus increasing the reliability of the air valve sealing capacity and reducing the risk of leakage. The pressure difference (ΔΡ) between an ambient pressure level (PI), and a waste water piping system pressure level (P2) constitutes the predetermined threshold under-pressure value at which waste water pipe under-pressures is equalized. When the air valve is operably mounted so that the movable valve member is movable in a vertical direction, the predetermined threshold under-pressure value may be an under-pressure value

corresponding to the weight of the movable valve member (131). In effect, the force required to open the valve may depend on the weight of the movable valve member and on the surface areas of the movable valve member subjected to the ambient pressure level (PI), and the waste water piping system pressure level (P2), respectively. According to embodiments of the air valve, the predetermined threshold under-pressure value may be selected to be a lower pressure value than the under-pressure value required for sucking liquid away from the liquid trap seal. Thus, the predetermined threshold under-pressure value may be selected dependent on the physical dimensions of a liquid trap seal coupled to the water pipe system (5) and the predetermined threshold under-pressure value may be selected dependent on the density of the relevant liquid. The liquid in the liquid trap seal may be e.g. water.

According to embodiments of the air valve, the predetermined threshold under-pressure value may be selected to be 150 Pascal. Providing air valve wherein the predetermined threshold under-pressure value is 150 Pascal may be suitable when the under-pressure value required for sucking liquid away from the liquid trap seal is substantially higher than 150 Pascal, such as in a range from 200 Pascal to 600 Pascal. Thus, for example, when the underpressure value required for sucking liquid away from the liquid trap seal is 500 Pa, and the predetermined threshold under-pressure value is 150 Pascal, there will advantageously be a safety margin of 350 Pa.

This solution has the advantageous effect of enabling this air valve to be mounted on a substantially horizontal waste water pipe which provides for a robust and space efficient mounting of the air valve. With this air valve, no extra connections or extra piping or bends have to be mounted to an essentially horizontal waste water pipe, and hence, both material and installation time is saved.

Thus, whereas the air valve disclosed in EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a substantially horizontal waste water pipe.

Whereas the prior art air valve of EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the outdoors mounting of the prior art air valve would require either a vertical waste pipe exiting through the roof of the building or the addition of a substantially 90 degree bend of a substantially horizontal waste pipe to obtain the required substantially vertical waste water pipe. By contrast, since the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a substantially horizontal waste water pipe, it enables mounting of the inventive air valve directly on a substantially horizontal waste water pipe that may be allowed to exit the building through a vertical side wall of the building.

In this manner the inventive air valve may be mounted at a substantially horizontal waste water pipe and, for physical stability, the body of the air valve may be attached to the vertical side wall of the building. Hence, a very robust construction is achieved.

Thus, when constructing a building comprising a waste water pipe system, material can be saved since the pipes which are arranged essentially horizontally do not have to be provided with vertical connections in order to be able to be fitted with an air valve. In addition, the air valve gives the advantage that for example a roof area may be kept clean since the air valves connected to the waste water system of the building may be attached to the wall instead of the roof, and hence the roof space may be utilized for other purposes.

Example E2. The air valve according to Example El, wherein the first angle (a) is in a range from 85-100 degrees.

This solution has the advantageous effect of enabling this air valve to be mounted on a substantially horizontal waste water pipe which provides for a robust and space efficient mounting of the air valve. With this air valve, no extra connections or extra piping or bends have to be mounted to an essentially horizontal waste water pipe, and hence, both material and installation time is saved.

Thus, whereas the air valve disclosed in EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a substantially horizontal waste water pipe.

Whereas the prior art air valve of EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the outdoors mounting of the prior art air valve would require either a vertical waste pipe exiting through the roof of the building or the addition of a substantially 90 degree bend of a substantially horizontal waste pipe to obtain the required substantially vertical waste water pipe. By contrast, since the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a substantially horizontal waste water pipe, it enables mounting of the inventive air valve directly on a substantially horizontal waste water pipe that may be allowed to exit the building through a vertical side wall of the building.

Example E3. The air valve according to any perceeding Example E, wherein the first angle (a) is substantially perpendicular. This solution has the advantageous effect of enabling this air valve to be mounted on a substantially horizontal waste water pipe which provides for a robust and space efficient mounting of the air valve. With this air valve, no extra connections or extra piping or bends have to be mounted to an essentially horizontal waste water pipe, and hence, both material and installation time is saved. Thus, whereas the air valve disclosed in EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a substantially horizontal waste water pipe.

Whereas the prior art air valve of EP 0 867 569 requires mounting at the upper end of a substantially vertical waste water pipe, the outdoors mounting of the prior art air valve would require either a vertical waste pipe exiting through the roof of the building or the addition of a substantially 90 degree bend of a substantially horizontal waste pipe to obtain the required substantially vertical waste water pipe. By contrast, since the air valve according to this aspect of the invention advantageously enables mounting of the inventive air valve at a substantially horizontal waste water pipe, it enables mounting of the inventive air valve directly on a substantially horizontal waste water pipe that may be allowed to exit the building through a vertical side wall of the building.

Example E4. The air valve according to any of Example E1-E3, wherein said channel part (180) comprises a channel part wall, said channel part wall extending in a direction substantially perpendicular to the plane (B) of the valve seat (140) so as to form said channel part (180), and wherein a distance (L) from the plane (B) of the valve seat (140), along a normal to the plane (B), to an end of the channel part wall defines a channel part length (L) of said channel part (180); and wherein the valve seat (140) encloses said air valve input (110), said air valve input (110) having an inlet cross-sectional area; and wherein the channel part length (L) is longer than 20% of the square root of the inlet cross- sectional area, and the channel part length (L) is shorter than 80% of the square root of the inlet cross-sectional area.

Example E5. The air valve according to any of Example E1-E3, wherein said channel part (180) comprises a channel part wall, said channel part wall extending in a direction substantially perpendicular to the plane (B) of the valve seat (140) so as to form said channel part (180), and wherein a distance (L) from the plane (B) of the valve seat (140), along a normal to the plane (B), to an end of the channel part wall defines a channel part length (L) of said channel part (180); and wherein said the valve seat (140) is ring shaped so as to enclose said air valve input (110), said ring shaped valve seat (140) having a valve seat radius; and wherein the channel part length (L) is longer than 30% of said valve seat radius, and the channel part length (L) is shorter than 70% of said valve seat radius. By providing a channel part attached to the air valve input, where said channel part has a certain length in relation to the air valve inlet cross-sectional area, tests have shown that an optimal flow of ambient air from the environment, in which the air valve is mounted, when the air valve is in a second state, may be received. Hence, for a certain required flow of air when the air valve is in the second state, the dimensions of the valve may be kept low by adapting the length of the channel part, saving space and material costs.

Example E6. The air valve (1) according to any of Example E 1-E5 wherein said channel part (180) has a funnel shaped opening (135). A funnel shaped opening of the channel part further improves the flow of ambient air from the environment into the housing body and further into the waste water piping system, when the air valve is in a second state. Hence, for a certain required flow of air from the environment into the waste water piping, when the air valve is in the second state, the dimensions of the valve may be kept low by shaping the channel part as a funnel, saving space and material costs.

Example E7. The air valve (1) according to any of Example E1-E6, wherein said channel part (180) has an inner surface (190), and wherein said movable valve member (131) comprises a head part (142) and a protruding element (143), which head part (142) is movably arranged inside the housing body (105) and which protruding element (143) is slidably arranged in a supporting structure (155), which supporting structure (155) is arranged in the channel part (180), wherein the supporting structure (155) is positioned within the channel part (180) by means of at least three supporting members (195) attached to the inner surface (190) of the channel part (180).

By using at least three supporting members for supporting and guiding the movable valve member as the states of the air valve changes, an optimal flow of air from the environment into the air valve when the air valve is in the second state is received and a robust construction of the air valve is achieved, due to the construction of the air valve parts. By using at least three supporting members for supporting and guiding the movable valve member as the states of the air valve changes, a robust and stable construction is achieved and at the same time, a minimal disturbance to the air flow due to the constructional elements placed in the flow of air from the environment into the air valve when the air valve is in the second state, is achieved. By using three supporting members in order to position the supporting structure in the channel part, an optimal flow of ambient air from the environment in which the air valve is mounted when the air valve is in a second state may be received and at the same time, a robust construction of the air valve is achieved. Hence, according to this aspect, for a certain required flow of air when the air valve is in the second state, the dimensions of the valve may be kept low, saving space and material costs. In addition, by using three supporting members, a robust construction of the air valve is received, wherein the positioning structure is kept in its position, supporting the valve member in an adequate manner. By orienting the supporting members in a certain way, the flow of ambient air from the environment in which the air valve is mounted when the air valve is in a second state may be received. By orienting one of the three supporting members in a direction E, a good flow of air through the air valve is achieved.

Example E8. The air valve (1) according to any of Example El-7 wherein one of the supporting members (195) is arranged in a direction (C), wherein the direction (C) is in a direction perpendicular to the first flat plane (A), wherein the supporting member (195) extends from the supporting structure (155) towards the air valve output (120).

According to one aspect, tests have shown that an optimal flow of ambient air from the environment in which the air valve is mounted when the air valve is in a second state may be achieved by placing one of the three supporting members in a direction (C), extending from the supporting member towards the air valve output, wherein the direction (C) is in a direction perpendicular to a virtual plane (A) defined by the orientation of the air valve output (120).

Example E9. The air valve (1) according to any of Example E1-E8 wherein an adapter part (200) is attached to the valve output (120), wherein said adapter part (200) is arranged to be attached to a waste water pipe (5).

This solution provides for an optimal flow of ambient air from the environment in which the air valve is mounted when the air valve is in a second state. This solution provides for a robust mounting of the air valve. The air valve is hence mounted in a robust way directly onto the wall of the building comprising the waste water pipe to which the air valve is attached. This construction provides for a sustainable and robust mounting of the air valve. I n addition, the mounted air valve provides for an appealing design of the air valve which does not disturb the environment. Example E10. The air valve according to any of Example E1-R9, wherein the predetermined threshold value may be selected to be a lower pressure value than that required for sucking liquid away from the liquid trap seal.

This solution has the advantageous effect of ensuring the integrity of liquid trap seals in the waste water piping system by equalizing under-pressure that may arise in the waste water pipe thereby also preventing odours from escaping via the liquid trap seal. This is because, when the pressure in the pipe is lower than the ambient pressure, the air valve will allow ambient air to enter so as to equalize the under-pressure, thus preventing the liquid in the liquid trap seal from being sucked away therefrom. If the liquid were sucked away from the liquid trap seal then air and sewer gases from the waste water pipe would be allowed to pass freely into the room where the liquid trap seal was installed.

Example Ell. The air valve (1) according to any of Example E1-E10 wherein the

predetermined threshold value is a value corresponding to the weight of the movable valve member (131). When the air valve is operably mounted so that the movable valve member is movable in a vertical direction, the predetermined threshold under-pressure value may be an underpressure value corresponding to the weight of the movable valve member (131). In effect, the force required to open the valve may depend on the weight of the movable valve member and on the surface areas of the movable valve member subjected to the ambient pressure level (PI), and the waste water piping system pressure level (P2), respectively. According to embodiments of the air valve, the predetermined threshold under-pressure value may be selected to be a lower pressure value than the under-pressure value required for sucking liquid away from the liquid trap seal. Thus, the predetermined threshold underpressure value may be selected dependent on the physical dimensions of a liquid trap seal coupled to the water pipe system (5) and the predetermined threshold under-pressure value may be selected dependent on the density of the relevant liquid. The liquid in the liquid trap seal may be e.g. water.

Example E12. The air valve (1) according to any of El-Ell wherein the predetermined threshold value is lower than 150 Pascal. According to embodiments of the air valve, the predetermined threshold under-pressure value may be selected to be 150 Pascal, or lower than 150 Pascal. Providing air valve wherein the predetermined threshold under-pressure value is 150 Pascal, or lower than 150 Pascal, may be suitable when the under-pressure value required for sucking liquid away from the liquid trap seal is substantially higher than 150 Pascal, such as in a range from 200 Pascal to 600 Pascal. Thus, for example, when the under-pressure value required for sucking liquid away from the liquid trap seal is 500 Pa, and the predetermined threshold underpressure value is 150 Pascal, there will advantageously be a safety margin of 350 Pa.

This solution has the advantageous effect of enabling this air valve to be mounted on a substantially horizontal waste water pipe which provides for a robust and space efficient mounting of the air valve. With this air valve, no extra connections or extra piping or bends have to be mounted to an essentially horizontal waste water pipe, and hence, both material and installation time is saved.

Example E13. The air valve (1) according to any of Example E1-E7 wherein the

predetermined threshold value is lower than 250 Pascal.

Example E14. A waste water piping system comprising: said waste water pipe (22) and the air valve (1) according to any of the preceeding Examples E1-E13 so as to equalize waste water pipe under-pressures.