EP3049584B1

EP3049584B1 - Odour trap with check valve and air admittance valve

Info

Publication number: EP3049584B1
Application number: EP14787015.8A
Authority: EP
Inventors: James Edward Mcalpine
Original assignee: McAlpine and Co Ltd
Current assignee: McAlpine and Co Ltd
Priority date: 2013-09-25
Filing date: 2014-09-22
Publication date: 2020-12-02
Anticipated expiration: 2034-09-22
Also published as: EP3049584A1; GB201317021D0; US20160230375A1; RU2016115747A; NZ718465A; RU2668333C2; HUE052974T2; ES2837973T3; AU2014326411A1; PL3049584T3; AU2014326411B2; GB2534516B; RU2016115747A3; WO2015044650A1; SG11201602327PA; GB2534516A; CA2925358A1; AU2014326411A2

Description

Field of the Invention

This invention relates to a trap for a waste outlet.

Background to the Invention

Water seal traps are widely used throughout the world in plumbing installations for buildings. A water trap is generally positioned between the outlet of a sink, basin, bath, shower etc., and the soil pipe to prevent odours, rodents and other undesirable entities which may be present in the soil pipe from entering the building through the outlet.
Various different types of trap exist and one well known and widely used trap is the bottle trap. Bottle traps are particularly popular because of their compact nature.
However, bottle traps have drawbacks. For example, where there are a large number of installations on the same plumbing system, a negative pressure differential can exist between the inlet side of the bottle trap and the outlet side.
If this pressure differential is large enough, the water forming the trap can get sucked away, exposing the environment surrounding the trap inlet to the contents of the soil pipe.
This problem has been partially alleviated by use of a one-way flow valve in the valve inlet, the one way flow valve providing a barrier between the trap inlet and the trap outlet in the event of the trap seal being sucked away. Whilst this barrier has proven to be successful at preventing the ingress of insects and the like, the one-way flow valve has been known to allow the ingress of odours.
US3707986 describes a one-way diaphragm for use in combination with the drain of a sink, where the diaphragm includes a plurality of axially extending, radially oriented, double thickness flanges which are corrugated throughout substantially their entire length. The lower end of each of the flanges is split such that water draining from the sink can flow. The diaphragm is made of resilient material so that the flanges are normally closed and provide a seal at their lower end to prevent backflow of any gases, fluids and foams into the sink.
EP 1 059 391 describes a valve for preventing a total or partial vacuum that sometimes occurs in sewage piping. Normally the valve is installed close to the anti-siphon trap that accompany sewage piping. This valve guarantees the hydraulic seal of the traps, as well as preventing unpleasant odours from reaching the outside. EP 1059 391 A2 describes a bottle trap in accordance with the preamble of claim 1.

Summary of the Invention

According to the present invention there is provided a bottle trap for a waste outlet as recited in claim 1.
In at least one embodiment of the present invention, there is provided a trap which, when connected to a soil stack, allows air into the trap outlet to relieve a negative pressure differential across the one-way pressure valve, that is when the pressure within the soil stack is less than the environmental pressure at the valve inlet. Generally, for a trap, this environmental pressure will also be the pressure at the trap inlet. This arrangement therefore ensures the pressure differential does not reach a sufficient level to generate a force sufficient to suck the water seal out of the trap and into the soil stack. In the event of a positive pressure differential of sufficient magnitude, however, the water seal is prevented from being pushed through the trap inlet by the inlet one-way flow valve.
For the avoidance of doubt, the phase "negative pressure differential" in this context means a pressure differential which would apply a pulling force to the water seal in a trap, which, in use, is such that the water seal experiences a force which, if the pressure differential reaches a sufficient magnitude, is strong enough to cause the water seal to flow through the trap outlet.
Mounting the one-way outlet pressure valve to the outlet neck ensures the one-way outlet pressure valve is located where the negative pressure differential which may exist between the trap inlet and trap outlet be strongest.
The presence of the air pocket ensures that should the trap backup and water enter the pressure valve outlet, the presence of an air pocket in the void prevents the backup water or waste in the bottle trap from contaminating the seal member and preventing the pressure valve member from shutting properly.

Brief Description of the Drawings

An embodiment of the present invention will now be described with reference to the accompanying drawings in which:

Figure 1 is a side view of a bottle trap for a waste outlet according to an embodiment of the present invention;
Figure 2 is a section view of the bottle trap of Figure 1 in an outlet pressure valve closed configuration;
Figure 3 is a section view through line A-A shown on Figure 2;
Figure 4 is a section of the bottle trap of Figure 1 shown in an outlet pressure valve open position;

Detailed Description of the Drawings

Reference is first made to Figure 1, a side view of a bottle trap, generally indicated by reference numeral 10 for a waste outlet (not shown) and, Figure 2, a section of the bottle trap of Figure 1 shown in an outlet pressure valve 24 closed position.
The bottle trap 10 comprises a trap body 12, defining a trap inlet 14 and a trap outlet 16. The body further includes an insert 18 for creating a convoluted flow path 20 between the trap inlet 14 and the trap outlet 16, such that a water seal 22, in use, exists between the trap inlet 14 and the trap outlet 16. The bottle trap 10 further comprises an inlet one way flow valve 23 located adjacent the trap inlet 14 and an outlet one way pressure valve 24 located on a neck 26 connecting the valve outlet 16 to the trap upper body 28.
The trap body 12 comprises an upper portion 28 and a lower portion 30, the lower portion being threadedly connected to the upper portion 28 by means of a threaded connection 32.
The inlet one way flow valve 23 comprises a polymer diaphragm valve adapted to permit the flow of fluid from the trap inlet 14 to the trap outlet. 16.
The one way outlet pressure valve 24, comprises a pressure valve inlet 34, a pressure valve outlet 36 and a pressure valve member 38. The pressure valve inlet 34 and the pressure valve outlet 36 are connected by a flow path 40. The pressure valve member 38 rests on the pressure valve member support 42, a pressure valve member lower surface 44 forming a seal with a support upper surface 46.
The seal between the pressure valve member 38 and the pressure valve member support 44 is maintained, in the absence of a pressure differential, by gravity, gravity pulling on the pressure valve member 38 to pull it down to engagement with the pressure valve member support 44.
If a pressure differential is present across the pressure valve member 38, the pressure valve member 38 will, in the case where the pressure in the trap 16 in the region indicated by "X" adjacent the trap outlet 16 is lower than the external environment, indicated by "Y" which is the environmental pressure present at the trap inlet 14 and the pressure valve inlet 34, lift away from the pressure valve member support 42, allowing air to flow through the passageway 40. This is shown more clearly in Figure 4, a section view of the bottle trap of Figure 1 shown in a pressure valve 24 open position.
If the pressure differential across the pressure valve member 38 is a positive pressure differential, that is the pressure at region "X" is greater than the external environment "Y" then the pressure valve member 24 is pressed into engagement with the pressure valve member support 42. This prevents noxious fumes from escaping from the soil pipe (not shown) which will be connected to the trap outlet 16. The pressure such a situation applies to push the water seal towards the inlet 14 is resisted by the one way inlet flow valve 23 which prevents the flow of fluid from the trap body 12 out of the trap inlet 14.
Relieving the negative pressure differential prevents a pulling force being applied to the water seal 22, preventing it being sucked from the flow path 20 and down the soil pipe. This ensures the water seal is maintained preventing ingress of noxious fumes and the like from the soil pipe through the convoluted flow path 20 and out of the trap inlet 14.
As can be seen from Figures 1, 2 and 4, the pressure valve inlet 24 and the pressure valve outlet 36 lie on different vertical planes. That is to say the direction of flow through the pressure valve inlet 34 and the direction of flow through the pressure valve outlet 36 are parallel but displaced apart.
This permits the inlet 34 and the outlet to 36 be arranged in a more complex formation and allows for the inlet 34 to have a gravity driven pressure valve member 38 but be located above the trap outlet 16. Locating the pressure valve member 38 above the trap outlet 16 reduces the possibility of flow in the trap 10 which is flowing out of the trap outlet 16 from contaminating the pressure valve member 38. This possibility is further reduced by the inclusion of a void immediately above the pressure valve member 38. The void provides a region in which air can be trapped providing a barrier between the pressure valve outlet 36 and the pressure valve inlet 34, such that if the soil pipe blocks and the trap 10 fills with fluid, the fluid will not be able to displace the air within the pressure valve passageway and flow over onto the pressure valve member 38.
Various modifications and improvements can be made to the above described embodiments without departing from the scope of the invention as defined in the appended claims.

Claims

A bottle trap (10) for a waste outlet, the bottle trap comprising:
a trap body (12) defining a trap inlet (14) and a trap outlet (16),

wherein the trap body (12) comprises an upper portion (28) and a lower portion 30, the lower portion being threadedly connected to the upper portion (28) by means of a threaded connection (32 and includes an insert (18), arranged relative to the inlet (14) and outlet (16) such that flow through the trap (10) is defined by a convoluted flow path (20) between the inlet (14) and the outlet (16) such that, when in use, a water seal (22) exists between the trap inlet (14) and the trap outlet (16),

a one-way outlet pressure valve (24) located on a neck connecting the trap outlet (16) to an upper portion (28) of the trap body (12), wherein the one-way outlet pressure valve (24) comprises a pressure valve inlet (34) and a pressure valve outlet (36) and a pressure valve member (38), wherein the pressure valve inlet (34) and a pressure valve outlet (36) lie on different vertical planes and are connected by a flow path (40), wherein the direction of flow through the pressure valve inlet (34) and the direction of flow through the pressure valve outlet (36) are parallel but displaced apart;

wherein the pressure valve member (38) rests on a pressure valve member support (42), and includes a void above the pressure valve member (38), wherein the void defines an air pocket, which provides a barrier between the pressure valve outlet (36) and the pressure valve inlet (34);

wherein a pressure valve member lower surface (44) forms a seal with an upper surface (46) of the pressure valve member support (42), wherein the seal between the pressure valve member (38) and the pressure valve member support (44) is maintained, in the absence of a pressure differential, by gravity, gravity pulling on the pressure valve member (38) to pull it down to engagement with the pressure valve member support (44); and wherein, when in use, in the presence of a negative pressure differential across the one-way outlet pressure valve (24), the one-way outlet pressure valve (24) is operable to open to allow air to pass through the one-way outlet pressure valve, wherein the pressure valve member (38) lifts away from the pressure valve member support (42), to relieve the pressure differential but in the presence of a positive pressure differential across the one-way outlet pressure valve (24), the one-way outlet pressure valve (24) is operable to close to prevent air passing through the outlet one-way pressure valve (24), wherein the pressure valve member (38) is pressed into engagement with the pressure valve member support (42);

characterised in that;

a polymer diaphragm one-way flow valve (23) provided by a duck bill valve is located within the trap body adjacent the trap inlet (14), wherein the duck bill valve (23) is housed within the insert, wherein the lower end of the duck bill valve (23) is immersed in the water providing the water seal (22), wherein the diaphragm one-way flow valve (23) permits flow of fluid from the trap inlet (14) to the trap outlet (16) but prevents flow from the trap outlet (16) to the trap inlet (14).