WO2011029134A1

WO2011029134A1 - Liquid trap assembly

Info

Publication number: WO2011029134A1
Application number: PCT/AU2010/001147
Authority: WO
Inventors: Ian Alexander Mackay
Original assignee: Polyfresh Holdings Pty Ltd
Priority date: 2009-09-10
Filing date: 2010-09-07
Publication date: 2011-03-17

Abstract

A liquid trap assembly typically a waste trap assembly (10) which is connected to a drain pipe (13), the trap assembly (10) having a liquid or water seal (18) therein through which waste liquid can flow in use and a one-way valve (29) which provides communication in one direction between the upstream side of the water seal (18) and drain pipe (13), the valve (29) preventing communication in the opposite direction to prevent odours escaping from the drain pipe (13).

Description

LIQUID TRAP ASSEMBLY

Technical Field

This invention relates to a liquid trap assembly for connection to or use in association with a drain pipe. This invention in a particular but not exclusive aspect relates to a waste trap assembly for use with a floor drain found in the typical building such as a house or multi-story building. It will therefore be convenient to describe the invention with reference to this application. It is to be clearly understood however that the trap assembly could also be used in an industrial environment and for draining liquids other than water.

Background Art

It is common to position a water seal in a drain pipe downstream of a drain opening of a drain. The purpose of the water seal is to block vermin, odour and germs from flowing in a reverse direction up through the drain and into the domestic air space above the drain. Such germs and odour can be unattractive and/or harmful to persons living in the domestic environment above the drain. A water seal is sometimes also known as a water trap and these two terms will be used interchangeably in the specification.

Known water seals consist of an S-bend, U-bend or P-trap in the drain pipe downstream of the drain opening. These different seals trap waste water in a loop of pipe such that the water acts as a lock or seal. That is, it acts as a barrier to gaseous flow in a reverse direction from the drain pipe up into the domestic air space above the drain. It is this barrier of water which performs the key sealing function and is the essence of the water seal or water trap.

These water seals are prone to blockage and do not permit easy access to the U- bend to remove material causing the blockage. Often access can only be gained to the blockage by removing a section of drain pipe downstream of the drain opening, eg the U bend. Yet further when the water seal or water trap is located between floors of a multistory building, the ceiling lining often has to be cut open to gain access to the blocked pipe. These water seals are also unwieldy and occupy a large amount of space.

A further shortcoming of existing water seals in drain pipes is that if an item of jewellery such as a finger ring inadvertently disappears down the drain opening it is difficult to retrieve and may even be lost.

One alternative to physically clearing a blockage in a U-pipe or S-pipe is to pour chemicals into the drain. However this is costly and potentially harmful to the environment and therefore is regarded as undesirable.

Yet a further disadvantage of drain pipes in buildings in particular multi-story buildings is that an air lock can form within the drain pipe when water is drained through the pipe due to the back pressure caused by water flowing through the pipe. This can affect efficient draining of water through the drain. Usually this can be overcome by providing an external venting system to the building which is connected to the drains at each level of a building. External venting systems of this type add substantially to the cost of a plumbing in a building. In addition, venting systems of this type are now not permitted in many local government jurisdictions.

It would be advantageous if a liquid trap could be devised which at least in part overcame one or more of the above disadvantages or which at least provided an alternative to the known art.

Summary of the Invention

According to a first preferred aspect, the present invention provides a liquid trap assembly, said trap assembly having a liquid seal therein through which waste liquid flows in use and means permitting flow of air or gas in a first direction from the upstream side to the downstream side of, to bypass said water seal.

Most preferably air or gas is prevented from flowing in a second direction opposite the first direction.

The trap assembly typically is adapted to be associated with a drain pipe of a drain. By permitting air to flow in from the upstream side to the downstream side of the water seal, a back pressure is not created allowing rapid draining of liquid through the drain. Further by preventing air or gas to flow in the opposite direction, odours cannot escape past the water seal.

Preferably valve means control the flow of air or gas in the first and second directions as above. The valve means suitably comprises one way valve means which allows air to enter the drain pipe but which prevents odour or gases escape from the drain pipe through the waste trap assembly. Preferably cover or shield means are provided over the valve means. Preferably the cover or shield means allows for communication of the valve means with the atmosphere externally of the waste trap assembly but protects or shields the valve means from waste liquid entering the drain. Preferably the valve means is shielded by the cover or shield means. According to another aspect, the present invention provides a waste trap assembly comprising:

a liquid reservoir;

a weir for maintaining a level of liquid in the reservoir;

a cover member over said weir and adapted to extend below the level of said weir into liquid in said reservoir whereby to define a liquid seal in said waste trap assembly.

In use, if water flows into the waste trap assembly, it is first directed into a pool of water formed in the reservoir before flowing under the cover member and over the weir and out away from the assembly usually into a drain pipe. The vertical distance between the weir and an inlet opening or openings in the cover member ensures that there will always be a body of water in the trap assembly which defines a water lock or water seal provided that a reasonably regular supply of water is passed through the waste trap assembly.

In one preferred form, valve means is associated with the trap assembly which allows for air to flow downwardly through the trap assembly when a back pressure is created in the waste trap assembly due to water flowing through the trap assembly. The valve means is such as to allow air to flow from the upstream side of the trap assembly in the general direction of water flow through the trap assembly but not in the opposite direction such that odour or gas is prevented from passing upwardly from a drain pipe through the waste trap assembly.

Preferably the valve means is provided on or in the cover member. The valve means suitably comprises a one-way valve. The valve may be any form of one-way valve such as a flap valve, spring loaded valve or other form of one-way valve. The valve suitably is arranged centrally of the cover member but may be arranged at another location on the cover member. The cover member may include one or more such valves.

Preferably means are provided to shield the valve means from water entering the waste trap assembly and to maintain communication of the valve means with the atmosphere upstream of the trap assembly and water seal. Preferably the shield means comprises a further cover member located over the first cover member to shield the valve means from liquid flowing into the waste trap assembly. Preferably the further cover member allows air communication between the valve means and the region upstream of the liquid seal. The cover member may surround the valve means and may have one or more openings therein to allow air communication between the valve means and upstream side of the water seal. Alternatively the cover member may be supported above the first cover member.

Suitably the weir is defined by a wall which extends upwardly from a lower side of the reservoir. Suitably the wall comprises a wall of the reservoir suitably an inner wall of the reservoir. Suitably the wall comprises a substantially annular or tubular wall which surrounds and defines a water flow outlet passage from the waste trap assembly. Suitably the reservoir has at least a bottom wall and the annular or tubular wall extends upwardly from the bottom wall and defines an inner side wall of the reservoir. Preferably the reservoir also includes an outer side wall which extends upwardly from the bottom wall and above the inner side wall. Water passing into the trap assembly thus flows into the reservoir and over the upper end of the inner side wall for flow into the outlet passage.

Preferably the reservoir is broadly circular in cross section. The reservoir may be defined by a floor waste socket which is connectable to a drain pipe and which is usually set with the floor of a building. An aperture or slotted grid or grate may be provided at the upper end of the socket and is usually substantially flush with the floor in which the floor waste socket is mounted. The grid or grate may be of any configuration and may have any drainage openings as is known in the art and may be detachably engaged with the waste socket by any suitably arrangement such as by means of lugs which cooperate with slots or grooves in the socket.

As an alternative, the reservoir is adapted to extend into a floor waste socket with the outer wall of the reservoir located adjacent to or juxtaposed with the inner wall of the socket. In this embodiment, the grid or grating may be provided at the upper end of the outer wall of the reservoir and is suitably detachably engaged therewith. Suitably the upper end of the outer wall includes an annular rib which is adapted to locate within an annular groove in the grid or grating. Advantageously the floor waste socket includes a flange which extends radially outwardly proud of the outer side wall of the reservoir to form a flange which in use rests on a support surface surrounding the socket.

The grid or grating may be seated on a shoulder at the upper end of the socket. Alternatively the grid or grating may have an outer frustoconical surface which is adapted to mate with a corresponding surface at the upper end of the socket. This will ensure substantial sealing between the grid or grating and socket to prevent odours or germs from the drain pipe escaping between the grid or grating and socket. The first cover member suitably is located coaxially with the inner wall of the reservoir. The first cover member suitably includes a top wall and a side wall, suitably an annular or cylindrical side wall, which extends downwardly from the top wall. The side wall suitably seats on the bottom wall of the reservoir and is secured thereto such as by adhesives or welding. Suitably the inlet opening or openings in the first cover member are provided in the side wall, the one or more openings being located lower than the upper end of the inner annular or tubular reservoir wall which defines the weir. Preferably the openings comprise two substantially diametrically opposed openings in the side wall of the first cover member.

The top wall of the first cover member may be of a domed or externally convex configuration to direct liquid to the side of the cover member. Suitably the top wall is provided with a central opening for receiving the valve means. The side wall of the cover member may project above the top wall thereof for a purpose described further below.

Preferably the further cover member includes a top wall which is also domed or externally convex to direct liquid away from the valve member. The cover member may also include a side wall, suitably an annular side wall, which extends downwardly from the top wall. The side wall of the further cover member suitably seats on the top wall of the first cover member. Suitably the side wall of the further cover member is located adjacent the upper protecting portion of the side wall of the first cover member, the projecting portion of the side wall serving to locate the side wall of the further cover member. Suitably the lower end of the side wall of the further cover member is secured such as by adhesives or welding to the top wall and/or protecting portion of the side wall of the first cover member. Suitably one or more openings are provided in the side wall of the further cover member to provide communication between the upstream side of the liquid seal and the valve carried by the first cover member.

In another embodiment, the top wall may be supported above the top wall of the first cover member by a series of spaced posts such that communication of the valve means with the atmosphere is permitted.

Suitably the components of the waste trap assembly are formed of a plastics composition which has a surface which has anti-viral or anti-bacterial properties.

Suitably the components of the trap assembly are either integrally moulded of the aforementioned plastics composition or one or more of the components of the trap assembly may be moulded of the aforementioned plastics composition and permanently attached to the remaining components. Suitably the plastics composition comprises a thermo-setting plastics or resin.

The anti-viral or anti-bacterial properties may be achieved by incorporating in the plastics an anti-viral or anti-bacterial material. Such a material may comprise an inorganic derivative containing silver. In use, silver ions migrate to the surface of the component and are released to suppress microbial growth.

In a preferred form, parts of the trap assembly form a single article which may be integrally moulded or formed.

In another aspect, the waste trap assembly suitably includes means adapted to expand when exposed to heat so as to prevent or reduce the passage of smoke and/or flames past the waste trap assembly.

The heat expandable means preferably is located beneath the reservoir. Preferably the heat expandable means comprises an intumescent material. The intumescent material may be provided in housing beneath the reservoir. The housing suitably has side walls to contain the intumescent material. The side walls may be formed such as to permit radial outward expansion of the intumescent material when exposed to heat. The side walls of the housing may thus be relatively thin or weakened walls.

The intumescent material alternatively may be attached to the underside of the reservoir and thus may expand radially with minimal constraint when exposed to heat.

Typically the intumesent material is provided in an annular configuration for location at or attachment to the underside of the reservoir.

Identifying means may be provided on or incorporated in each trap assembly to identify the trap. The identifying means may include or comprise an RFID tag or the like. The RFID or the like may be incorporated in the plastics of the trap assembly.

Brief Description of the Drawings

Reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention and wherein:

Fig. 1 is an isometric view of a waste trap assembly in accordance with a first embodiment of the invention with grid detached for use as a bathroom or other floor drain outlet;

Fig. 2 is an exploded isometric view of the trap assembly of Fig. 1;

Fig. 3 is a cross sectional view of the trap assembly of Fig. 1; Fig. 4 is a cross sectional view of a waste trap assembly according to a second embodiment of the invention;

Fig. 5 is a cross sectional view of portion of a further trap assembly corresponding to the region X of Fig. 4;

Fig. 6 is a cross sectional view of a waste trap assembly according to a further embodiment of the invention; and

Fig. 7 is a cross sectional perspective view of a waste trade according to another embodiment of the invention which is similar to the embodiment of FIGS. 1 to 3.

.Detailed Description of the Preferred Embodiment

Referring to the drawings and firstly to Figs. 1 to 3, there is illustrated a waste trap assembly 10 in accordance with an embodiment of the invention which is typically used in a bathroom floor drain or other floor drain or bathroom shower floor drain. The waste trap assembly 10 includes in this embodiment a waste outlet socket 11 which is adapted to be set with the floor 12 of a building such as a concrete floor and which is coupled to a drain pipe 13 in a conventional manner. The outlet socket 11 of the waste trap assembly 10 defines a water container or reservoir 14 which includes an outer cylindrical wall 15, an annular bottom wall 16 and an inner annular wall 17 so as to define between the inner and annular walls 17 and 15, an annular water chamber 18. The inner annular wall 17 surrounds and defines a waste outlet passage 19 which communicates with the drain pipe 13. The upper edge 20 of the wall 17 defines a weir over which water flows as described further below. The socket 11 also includes an outer flange 21 which extends outwardly from the outer side wall 15 which seats in use on a shoulder 22 in the floor. The upper flange 21 is aligned with the floor 12 surrounding the trap assembly 10 to be substantially flush with the upper surface of the floor slab 12.

A first cover member 23 is located coaxially relative to the walls 15 and 17 and includes a domed top wall 24 and an annular or cylindrical side wall 25 which extends downwardly from the top wall 24 and seats on the bottom wall 16 to be joined and be connected thereto by adhesives or welding. Two opposite rectangular openings 26 are defined in the side wall 25 with the upper edges 27 thereof being located below the upper edge 20 of the side wall 17 to thereby define a water trap or seal. The water level is typically up to 20 mm or more above the edges 27 of the openings 16. The openings 26 may be other than of a rectangular configuration for example they may be circular and may be any suitable size or may be of any number to ensure substantially unrestricted passage of water through the trap assembly 10.

A central opening 28 is provided in the domed top wall 24 of the cover member 23 and a one-way valve 29 is sealingly secured within the opening 28, the valve 29 permitting the flow of air downwardly past the cover member 23 but preventing air flow in the opposite direction. The side wall 25 of the cover member 23 also extends or projects slightly upwardly beyond the top wall 24 as at 30.

The embodiment of Figs. 1 to 3 also includes a second cover member 31 which includes a top wall 32 of a domed configuration and a cylindrical side wall 33 which extends downwardly from the top wall 32. The side wall 33 is of slightly smaller diameter that the side wall 25 such that it may seat on the top wall 24 of the cover member 23 adjacent the projecting portion 30 of the side wall 25 which locates the side wall 33. The side wall 33 may be secured to the top wall 24 and/or projecting wall portion 30 by adhesives or welding. Two opposite rectangular openings 34 are defined in the side wall 33 at the lower edge of the side wall 33 for the passage of air as described further below. The openings 34 may also be other than of a rectangular configuration for example they may be circular and typically are relatively small so that water is prevented from reaching the valve 29. A typical size is 2 to 4 mm. There also may be any number of openings 34 as required.

An apertured grid or grate 35 is fixedly or detachably mounted on the top of the socket 12 seating on a shoulder 36 therein. The grid or grate 34 is typically substantially flush with the floor of the shower or bathroom and may as shown in Fig. 1 have lugs 37 which locate in slots 38 in the interior of the socket 11 to detachably secure the grid or grate 35 to the socket 11 by rotation thereof relative to the socket 11. The grid or grate 35 when engaged with the socket 11 is circumferentially surrounded by the flange 21.

In use and when water is collected by the waste trap assembly 10, water flows in the direction indicated by the arrows marked A past the grid or grate 35 into the annular chamber 18 where it forms a pool as indicated in Fig. 3. The depth of water in the pool is determined by the weir formed by the upper end 20 of the wall 17. This forms the water seal or water trap with the annular chamber 18 as the upper edges 27 of the openings 26 are submerged in the pool of water within the chamber 18. This acts to provide a barrier to gaseous flow upwardly through the waste trap assembly 10 and into the space above the assembly 10.

The one-way valve 29 allows air to enter into the drain pipe 13 from upstream of the trap assembly 10 and water seal thereof in the direction marked by the arrows B through the grid or grate 35 and through the openings 34 to thus avoid a vacuum forming within the pipe 13 which would hinder drainage. The one-way valve 29 however will prevent odour or gases passing upwardly in the opposite direction and thus smells, odours and germs remain trapped within the drain pipe 13 downstream of the trap assembly 12. Water flowing into the waste trap assembly 10 however will be deflected away from the valve 29 by the domed top wall 32 of the cover member 31 which provides a shield to the valve 29.

In the embodiment of Fig. 4, the waste trap assembly 37 is of similar configuration to the waste trap assembly 12 and like components have been given like numerals. In this case however the outlet socket 38 is a separate component and the trap assembly 37 is adapted to be received coaxially in the socket 38. The outer cylindrical wall 15 of the trap assembly 37 in this case is engaged at its upper end with a grid or grate 39 by means of an outer annular rib 40 which in this case is detachable engaged with an annular groove 41 in the grid or grate 39. In addition, the grid or grate 39 has an outer frusctoconcial surface 42 which is adapted to mate with a corresponding frustoconical surface 43 in the upper end of the socket 38. This will substantially seal the outer edge of the grid or grate 39 to the socket 38 which will prevent or substantially minimise gaseous flow upwardly and externally of the trap assembly 37 between the socket 38 and wall 15 of the trap assembly. Sealing may be enhanced by the addition of suitable sealing material between the surfaces 42 and 43.

Fig. 5 illustrates portion of an alternative trap assembly 44 which is of a similar configuration to the trap assembly 37 of Fig. 4. In this case however the grid or grate 45 seats on a shoulder 46 at the upper end of the socket 47. The wall 15 of the trap assembly 44 engages with the grid or grate 45 in a similar manner to that described above. In addition, a sealing material may be provided between the shoulder 36 and grid or grate 45 to prevent escape of odours from between the wall 15 and socket 47.

The waste trap assembly 48 of Fig. 6 is in the same configuration as the trap assembly of Figs. 1 to 3 except that it does not include the valve 29 or second cover member 31. Further the first cover member 23 in this case does not include a valve 29 or opening 28 and is thus in a similar configuration to the further cover member 31. The trap assembly 48 functions substantially in the same manner as the trap of Fig. 6 with waste liquid flowing in the direction C through the trap assembly and water seal defined in the reservoir 18 except that no vacuum relief is provided. The form of waste trap assembly of Fig. 6 may also be used in the configuration of Figs. 4 or 5.

The components of the trap assemblies described above are preferably formed of a plastics composition and most preferably of a plastics composition which has a surface which has exhibits anti-viral or anti-bacterial activity and the respective components of the trap assembly are moulded of the aforementioned plastics composition and permanently attached to the remaining components. The plastics composition typically comprises a thermo-setting plastics or resin.

The anti-viral activity may be achieved by incorporating in the plastics composition an inorganic derivative containing silver with silver ions migrating to the surface of the waste assembly to be released to suppress microbial growth.

From time to time when it is desirable to clean out the chamber 18, the grate or grid 39 or 45 with attached waste trap assembly 37 of Figs. 4 and 5 can easily be lifted upwardly out of the socket 38. This enables the water trap or water seal formed by the chamber 18 to be cleaned out and valuable items, eg. finger rings, to be recovered from the chamber 18 if appropriate. The waste trap assembly 38 can then easily and efficiently be returned to the socket 36.

Referring now to Fig. 7, there is illustrated a further embodiment of waste trap assembly 51 which is similar to the embodiments of Figs. 1 to 3 and in which like components to the embodiment of Figs. 1 to 3 have been given like numerals. The waste trap assembly 51 includes an outer housing or socket 11 located within a drain pipe 13 located within a floor 12 and which includes an inner hollow member of an inverted funnel-like configuration which has a tubular wall 17 which joins through a frustoconical portion 52, the bottom wall 16 of the housing 11. The inner annular wall 17 surrounds and defines the waste outlet passage 19 which communicates with the drain pipe 13.

A cover member 23 is located coaxially relative to the walls 15 and 17 and includes a domed top wall 24 and an annular or cylindrical side wall 25 which extends downwardly from the top wall 24 and seats on the bottom wall 16 to be joined and be connected thereto by adhesives or welding. Two opposite rectangular openings 26 are defined in the side wall 25 with the upper edges 27 thereof being located below the upper edge 20 of the side wall 17 to thereby define a water trap or seal.

A one-way valve 29 is provided in the top wall 24 of the cover member 23 which permits the flow of air downwardly past the cover member 23 downstream of the water seal but prevents air flow in the opposite direction. .

A further cover member or cap 31 is mounted centrally to the top wall 24 of the cover member 23 by a series of spaced posts 53 which extends downwardly from the top wall 32. The cover member or cap 31 being located above the valve 29 prevents water entering the waste assembly 51 hitting the valve 29 with the curved or dome top surface 32 of the cover member or cap 31 directing water away from the valve 29 and to the side of the cover member 23 whilst air can enter the valve 29 through the regions 54 between the posts 53.

As with the previous embodiments an apertured grid or grate 35 is fixedly or detachably mounted on the top of the socket 11, the grid or grate 35 typically being substantially flush with the floor of the shower or bathroom.

Waste water entering the grid or grate 35 enters the housing 11, flows through the openings 26 and over the top end of the wall 17 which defines a weir and then to the waste line or pipe 13. Water entering the housing 11 forms a water seal as the openings 26 are lower than the top of the wall 17. The one way valve 29 permits air from the area above the grid or grate 35 to pass into the pipe 13 through the outlet 19 thus preventing an air lock whilst the valve 29 will prevent odours from escaping from the pipe 13 to the area above the grid or grate 35.

For fire protection purposes, each of the above described waste trap assemblies may include means adapted to expand when exposed to heat so as to prevent or reduce the passage of smoke and/or flames past the waste trap assembly. Such means suitably is in the form of an intumescent material 49 provided in an annular form as shown in dotted outline in Fig. 3, the material 49 being attached to the bottom wall 16 of the reservoir 14 for example by fasteners e.g. suitably clips or adhesives. When exposed to heat from fire, the material 49 will radially expand inwardly to block the drain passage 19 and therefore prevent propagation of fire and prevent passage of smoke or gas through the drain pipe 13. A similar arrangement may be used with the waste trap assemblies of Figs. 4, 5 and 6.

Each trap assembly may carry an RFID tag or other identifying device 50 (see

Fig. 3) which may be incorporated in the plastics of one of the components of the waste trap assembly 10. This enables the waste trap assemblies to be monitored for security purposes as required. The trap assembly as described above may be used as the primary waste assembly in a drain to provide a water or liquid seal in a drain line or may be used as a supplemental waste assembly in a drain to provide an additional water or liquid seal. The principles of the waste assembly described above may be incorporated in any form of waste assembly or trap such as a mini-trap, a bottle trap or a partition trap.

The terms "comprising" or "comprises" as used throughout the specification are taken to specify the presence of the stated features, integers and components referred to but not preclude the presence or addition of one or more other feature/s, integer/s, component/s or group thereof.

It will of course be realised that while the above has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as defined in the appended claims.

Claims

1. A liquid trap assembly having a liquid seal therein through which waste liquid can flow in use and means permitting flow of air or gas in a first direction from the upstream side to the downstream side of, to bypass said water seal.

2. A liquid trap assembly as claimed in claim 1 wherein air or gas is prevented from flowing in a second direction opposite the first direction.

3. A liquid trap assembly as claimed in claim 2 and including valve means for controlling the flow of air in said first and second directions.

4. A liquid trap assembly as claimed in claim 3 wherein said valve means comprises one way valve means.

5. A liquid trap assembly as claimed in claim 4 and including cover or shield means over the valve means, said cover or shield means allowing for communication of the valve means with the upstream side of said water seal and protecting or shielding said valve means from waste liquid entering said trap assembly.

6. A waste trap assembly comprising:

a liquid reservoir;

a weir for maintaining a level of liquid in the reservoir;

7. A waste trap assembly as claimed in claim 6 wherein valve means are provided on or in the cover member.

8. A waste trap assembly as claimed in claim 7 wherein said valve means comprises a one-way valve.

9. A waste trap assembly as claimed in claim 8 wherein said valve is arranged centrally of the cover member.

10. A waste trap assembly as claimed in any one of claims 7 to 9 and including means for shielding the valve means from liquid entering the waste trap assembly and to maintain communication of the valve means with the upstream side of said liquid seal.

11. A waste trap assembly as claimed in claim 10 wherein said shield means comprises a further cover member located above the first cover member.

12. A waste trap assembly as claimed in claim 11 wherein said further cover member has one or more openings therein to allow communication between the valve means and the upstream side of said liquid seal.

13. A waste trap assembly as claimed in claim 11 wherein said further cover member is supported at a spacing above the first cover member.

14. A waste trap assembly as claimed in any one of claims 11 to 13 wherein the upper side of said further cover member is convexly curved externally.

15. A waste trap assembly as claimed in any one of claims 7 to 14 wherein said weir is defined by an inner wall which extends upwardly from a lower side of the reservoir.

16. A waste trap assembly as claimed in claim 15 wherein said inner wall comprises a substantially annular or tubular wall which surrounds and defines a liquid flow outlet passage from the waste trap assembly.

17. A waste trap assembly as claimed in claim 16 wherein said reservoir has at least a bottom wall and wherein the annular or tubular wall extends upwardly from or is joined to the bottom wall and defines an inner side wall of the reservoir.

18. A waste trap assembly as claimed in claim 17 wherein said reservoir includes an outer side wall which extend upwardly from the bottom wall and above the inner side wall.

19. A waste trap assembly as claimed in claim 17 or claim 18 wherein said first cover member is located coaxially with the inner wall of the reservoir and includes a top wall and a side wall extends downwardly from the top wall and surrounding the inner wall, said sidewall having one or more openings therein.

20. A waste trap assembly as claimed in claim 19 wherein said top wall is of a domed or externally convex configuration. 21. A waste assembly as claimed in claim 20 wherein said top wall is provided with a central opening for receiving the valve means.

20. A waste trap assembly as claimed in claim 20 and wherein an apertured or slotted grid or grate is provided at the upper end of the top wall.

21. A waste trap assembly as claimed in claim 20 wherein the upper end of the outer wall includes an annular rib which is adapted to locate within an annular groove in the grid or grating.

22. A waste trap assembly as claimed in claim 20 or claim 21 an including a floor waste socket which receives said reservoir, said socket having a flange which extends radially outwardly proud of the outer side wall of the reservoir to form a flange which in use rests on a support surface surrounding the socket.

23. A waste trap assembly as claimed in claim 22 wherein said grid or grating has an outer frustoconical surface which is adapted to mate with a corresponding surface at the upper end of the socket.

24. A waste trap assembly as claimed in any one of claims 6 to 23 and means associated with said waste trap assembly and adapted to radially expand when exposed to heat so as to prevent or reduce the passage of smoke and/or flames past the trap assembly.

25. A trap assembly as claimed in claim 24 wherein said heat expandable means is located beneath the reservoir.

26. A trap assembly as claimed in any one of the preceding claims and including identifying means may be provided on or incorporated in each trap assembly to identify the trap.

27. A waste trap assembly as claimed in claim 26 wherein said identifying means includes or comprises an RFID tag or the like.