GB2573341A

GB2573341A - Plumbing device

Info

Publication number: GB2573341A
Application number: GB1807399.9A
Authority: GB
Inventors: Winston Armstrong Russell
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-05-04
Filing date: 2018-05-04
Publication date: 2019-11-06
Also published as: GB201807399D0

Abstract

The connector 10 has an inlet 12, a main body 14 and an outlet 16, the body being open sided forming a tundish providing an air gap 20 between the inlet and outlet, through which water can fall in use, the connector including a flow straightener 22 to direct flow from the inlet to the body. The flow straightener may be a series of ribs 22 circumferentially located around the inside of the preferably tubular inlet, and axially extending along the path of water flow in use. The ribs may extend into the air gap from the edge of the inlet, and be integrally formed with the inlet. The body may have circumferential chamber wall 38 with a shelving floor 40 dividing it into upper and lower chambers, with a spring biased one-way valve in the floor between the chambers held by valve guide 45/44, to preventing any backflow. Arms 38 may extend between the chamber wall 38 and inlet 12. The flow straightener may minimise spraying or splashing of hot water in use.

Description

TITLE OF THE INVENTION

PLUMBING DEVICE

BACKGROUND OF THE INVENTION

The present invention relates to a plumbing device which allows a pressure and/or temperature relief valve for a fresh water system to be connected to a waste pipe or soil stack without the risk of back contamination or odours.

An example of the use of a relief valve is with an unvented domestic hot water storage system (UVHWSS) or unvented hot water heater (UVHWH). Such a system typically has a temperature and/or pressure relief valve connected to a discharge pipe. The regulations for connection of the discharge pipe to a waste water system are strict because of the risk of back contamination from the pathogenic water in the waste water system to the fresh water in the storage system. Typically, the regulations require a tundish to provide a visible point of discharge and an air gap (to provide backflow prevention) and the outflow from the tundish to be connected in a particular way to discharge above an external ground floor gulley. Such a connection requires careful engineering and is expensive to install.

For boiler applications, backflow contamination is typically not an issue but the visibility of a point of discharge from a boiler remains relevant.

In order to connect a vent valve to a sewer, i.e. at a soil stack within a building, arrangements need to be made to provide an odour trap to prevent any foul gases from the soil stack from entering the domestic location. On most domestic installations, a water trap would be used to prevent escape of gases and odours from the soil stack. Typically, a water trap comprises a bent tube in which water is trapped. A water trap allows passage of liquid and suspended solids but not gases. Generally speaking, a water trap is not suitable for use with a tundish connected to a pressure relief valve (PRV) as it will become ineffective through drying out. A water trap is also relatively bulky and is not suitable for use in all locations.

The applicant’s own prior patent applications GB2522634 and GB2541476 disclose a plumbing connector with a non-return valve so as to provide a dry trap tundish. Whilst such products mitigate the above described technical challenges, ongoing development work has revealed that further improvement to the products disclosed in the applicant’s prior patent applications is possible. The present disclosure concerns such developments.

One problem is that the introduction of valve components and a support structure introduces an obstruction to fluid flow. Accordingly such components can reduce the maximum possible flow rate through the connector.

Since (side) openings are provided in the tundish to provide the requisite air gap, this also creates a risk of scalding due to any discharge of water at elevated temperatures through the openings.

It is an aim of the invention to provide a connector for a water system that resolves or mitigates one or more of the above-identified issues.

BRIEF SUMMARY OF THE INVENTION

According to the invention, there is provided a connector for a water system, the connector comprising an inlet connector, a connector body and an outlet connector arranged in sequence, wherein the connector body is open-sided so as to form an open air gap between the inlet and outlet through which water can fall in use, the connector comprising one or more flow straightener arranged to direct flow from the inlet into the connector body.

The one or more flow straightener may be located at the inlet connector. The one or more flow straightener may depend from the inlet connector.

The one or more flow straightener may be integrally formed with the inlet connector.

The inlet connector may comprise a peripheral wall defining a flow passage (e.g. an inlet opening) though the inlet connector. The one or more flow straightener may extend into the flow passage and/or inlet opening. The one or more flow straightener may extend into the flow passage in a substantially radial direction,

e.g. part way into the flow passage.

The one or more flow straightener may have a height (e.g. radial) dimension that is less than half the width of the flow passage (e.g. less than the flow passage radius). The height dimension of the/each flow straightener may be less than, or equal to, one third, one quarter, or one fifth of the width of the flow passage or its radius.

The one or more flow straightener may comprise a rib, ridge or partial wall.

The one or more flow straightener may be elongate in form and may extend in an axial direction, e.g. in a direction parallel to a central axis of the inlet connector or the connector as a whole.

A plurality of flow straighteners may be provided. Three, four, five, six, seven or more flow straighteners may be provided. Eight flow straighteners may be provided.

The flow straighteners may extend in a parallel direction, e.g. a direction of flow along or from the inlet connector. The flow straighteners may extend towards the outlet connector.

The plurality of flow straighteners may be angularly spaced apart. The flow straighteners may or may not be equally spaced apart. The plurality of flow straighteners may be provided as an annular or circumferential array, e.g. a symmetric array about a central axis.

The connector body may comprise an internal floor formation between the inlet connector and outlet connector, e.g. beneath the open air gap defined by the open-sided connector body. The floor formation may divide the interior of the connector body into upper and lower internal chamber portions.

An opening, e.g. a valve opening may be formed in the internal floor formation.

The inlet connector may be supported above the connector body and/or the open upper chamber by one or more arms.

The one or more flow straightener may depend from the inlet connector towards the connector body, e.g. in the direction of the floor formation or the opening therein.

The one or more flow straightener may have a distal or free end, e.g. beneath the inlet connector. The inlet connector may have opposing upper and lower rims, the internal flow passage of the inlet connector extending between said upper and lower rims. The one or more flow straightener may depend down from the lower rim.

The one or more flow straightener may be tapered towards a free end thereof. The one or more flow straightener may taper towards a tip. The tip may be rounded.

The one or more flow straightener may take the form of a prong or beak.

An inner edge or free/distal end of the or each flow straightener may lie within a radial distance of a central axis of the connector that is less than or equal to a radius of the opening in the floor formation and/or an outlet connector opening. The majority or all of each flow straightener may lie within said radial distance of the central axis.

The connector body and/or a lower chamber thereof may be closable by a nonreturn valve which is arranged to open at a pre-selected pressure, e.g. according to a predetermined weight of water acting thereon. The flow straightener may extend towards the non-return valve.

The connector may comprise a non-return valve within the connector body. The non-return valve may be supported by one or more strut. The non-return valve may comprise a valve stem and/or a spring.

The connector body may comprise a shelving floor defining upper and lower chamber portions inside the chamber body. The flow straighteners may direct the flow to an opening in the floor, e.g. an upper chamber outlet.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described by way of example only, with reference to the Figures, in which:

Figure 1 is a three-dimensional view of a connector according to an example of the present invention;

Figure 2 is a plan view of the connector of Figure 1;

Figure 3A is a front view of the connector of Figure 1;

Figure 3B is a side view of the connector of Figure 1; and, Figure 3C is a longitudinal section view of the connector of Figure 3B through a plane A-A.

DETAILED DESCRIPTION

The invention has arisen from studying the fluid flow through connectors of the type disclosed in prior patent applications GB2522634 and GB2541476. However the findings can be more widely applied to other tundish devices, regardless of whether or not they have a non-return halve housed therein.

A first example of a connector is indicated generally at 10 as shown in Figure 1. Connector 10 has an inlet connector 12, a central connector body portion 14 and an outlet connector 16,

Inlet connector 12 is supported above the body portion 14 by a pair of diametrically opposed arms 18 such that a vertical/air gap 20 is formed between the inlet 12 and the body portion 14. Arms 18 are arranged so that the gap 20 is of a height sufficient to provide an air brake to drain, e.g. suitable for connection to a soil or foul drain in potable water applications. In alternative examples of the connector, there could be provided a single arm 18 or more than two arms 18 of width/shape sufficient to provide the requisite air gap, and to permit viewing of any liquid discharge through the connector, whilst also being of sufficient strength to support the spaced relationship between the inlet connector 12 and body portion 14.

This disclosure concerns the manner in which liquid flows from the inlet through the air gap and into/through the body portion 14 to the flow outlet through outlet connector 16.

The inlet connector comprises flow straightener formations 22 with the aim of creating a desired flow regime through the connector in use. In particular, it has been found that splashing and other, seemingly minor, misdirections of flow from the inlet through the air gap 20 can have a relatively large impact on the flow regime and the achievable flow rate. In the example of Figure 1, the impacting of flow on the valve and support features (to be described below) in the connector interior causes stagnation points in the flow at the point of impact and diversion of the flow laterally by way of flowing around the obstruction or else by splashing.

These flow phenomena have been found to affect the flow field upstream at the inlet. That is to say, since liquid is incompressible, the changes in flow velocity and pressure are communicated upstream through a continuous stream of liquid flowing through the air gap 20. It has been found that, by controlling the flow field/regime through the inlet and improved flow performance through the connector body can be achieved, even when obstructions in the connector body are present.

Turning to Figures 2 and 3, it can be seen that the inlet connector 12 has an internal flow passage defined by the internal surface 24 or bore through the inlet connector. The flow passage is curved/circular in section in this example.

The inlet connector 12 thus defines a relatively short flow conduit for connection to an adjacent pipe in use. It has been found that this short conduit and the connection to an adjacent pipe upstream can create turbulence in the flow field, i.e. as well as the influence of any downstream obstructions. Any turbulence in the flow field (i.e. any departure from a uniform laminar flow field) can reduce the maximum flow achievable through the connector and can increase the likelihood of the flow spreading laterally upon exiting the inlet connector, through the air gap 20.

An annular array of flow straighteners 22 is provided at the inlet connector. In this example, eight flow straighteners are provided at angular spacings around the internal surface 24 of the inlet connector flow passage. The flow straighteners are equally spaced in this example. Different numbers and/or spacings of the flow straighteners could be considered for other embodiments.

The flow straighteners take the form of partial walls or ribs extending part-way into the flow passage. The flow straighteners have a height dimension, i.e. in a radial direction with respect to a longitudinal or central axis 26, i.e. contained within the plane A-A, shown in Figure 3B, that is less than half of the width/diameter of the flow passage. In this manner, the flow straighteners do not span the entire width, or else meet with an opposing flow straightener on the other side of the flow passage. Instead the flow straighteners extend only part way into the flow passage to leave a central open section of the flow passage in which the flow straighteners are not present.

In this example, each flow straightener extends between one quarter and one fifth across the flow passage width/diameter or approximately one quarter of the way into the flow passage in a radial direction. Different heights of the flow straightener walls may be considered.

The flow straighteners are elongate in form in the direction of the axis 26, e.g. the global flow direction through the connector.

The flow straighteners take the form of relatively thin and planar/straight walls, i.e. having a width dimension that is significantly smaller than its length. The width dimension is smaller than the height dimension also. Additionally or alternatively, the width dimension is smaller than the spacing between the flow straighteners (e.g. in a circumferential direction).

As best shown in Figure 3C, the flow straighteners have a first/proximal end 28 located within, or at the outlet of, the inlet connector 12 and a second/distal end 30 located externally of the flow passage 24 through the inlet connector 12. In this regard the inlet connector 12 has an outlet opening defined by a lower rim/edge 32 and the flow straighteners protrude beyond said outlet rim 32. The distal end 30 of each flow straightener is thus a free end depending into the air gap 20 and/or downwardly from the inlet connector.

The flow passage through the inlet connector may narrow or taper slightly in the vicinity of the flow straighteners, e.g. towards the rim 32.

The flow straighteners 22 are tapered towards the distal ends 30 and may be angled or curved/rounded in form so as to define tips at the free ends thereof. The flow-straighteners may be generally claw-like or prong-like in profile.

The proximal ends 28 of the flow straighteners 22 may be flat and/or perpendicular to the axis 26.

The inlet connector 24 takes the form of a generally annular body having an upper rim 34 at the upper edge thereof, opposite to the rim 32. The inlet connector 12 in this example comprises one or more step 36 defining adjoining sections of differing internal and/or external diameter between the upper 34 and lower 32 rims. In this specific example, two steps 36 are provided.

The inlet connector in this example is a push-fit type connector, e.g. a universal push-fit connector for different diameter pipes. However in other examples, the inlet connector need not have steps therein and could take the form of a simple annular wall, e.g. having a connector formation, such as a screw thread, thereon for attachment to a conventional pipe, tap connector or other pipe fitting.

The connector body 14 comprises a circumferential chamber wall 38 and a shelving chamber floor 40, which define the shape of an open chamber within the body. The chamber is referred to in the context of this example as an upper chamber. The upper chamber has an open mouth for receiving liquid from the inlet.

The chamber wall 38 supports the one or more arms 18, which depend from an upper edge of the wall 38. Chamber floor 40 forms upper chamber floor opening 42 such that upper chamber floor 40 has an inverted truncated conical shape and such that the upper chamber floor 40 has a funnel shape for directing liquid to the upper chamber floor opening 42.

In this example, the opening 42 has a depth, e.g. formed by a rim/lip formation in the floor 40, thereby defining a middle chamber at the bottom of the upper chamber. The middle chamber may be considered part of the upper chamber.

Upper chamber wall 38 has inwardly projecting arms, in the form of struts/ribs 44, which support valve guide 45, typically aligned with the central axis 26, e.g. between the inlet flow passage 24 and the opening 42, in the interior of the upper chamber. One, two, three or more ribs 44 could be used.

Upper chamber wall 38 is generally annular in form so as to define the upper chamber as an open-ended drum. The rib(s) 44 depend into the interior space within the wall 38.

A lift valve is provided for closing the opening 42 in the shelving floor 40.

The lift valve has the following components: a valve stem 46, a valve member/disc 48, a valve spring 50 and a valve spring clip/retainer 52. The valve stem 46 is arranged to run through valve guide 45. At an upper part of the valve stem 46 above the valve guide 45, valve spring 50 is arranged on the valve stem 46 and secured to an upper end of the valve stem 46 by valve spring clip 52. At a lower end of the valve stem 46, the valve disc 48 is secured by a valve disc fixing. Valve disc 48 is formed from a resilient material such as a plastics or rubber material, for example EPDM rubber. In an alternative embodiment, the valve spring 50 may be replaced by a suitable resilient member as would be known to a person of skill in the art.

The tubular middle chamber 42 has a lower opening/rim which forms a valve seat for valve disc member 48 and which lower opening is normally closed by valve member 48, which is biased by the valve spring 50 into that position. The valve spring 50 is arranged to open the lift valve at a pre-selected pressure on the valve member 48. A suitable pre-selected pressure may be that determined by when the tubular middle chamber is full of liquid.

A lower chamber 54 has a ceiling formed by the shelving floor 40 of the upper chamber, a tubular lower chamber wall 56 and a shelving or tapered lower chamber floor 58. The ceiling comprises the opening 42 which is normally closed by valve 48.

Lower chamber floor 58 narrows to form an opening for connector outlet 60 such that lower chamber floor 58 has an inverted truncated conical shape and such that the lower chamber floor has a funnel shape for directing liquid to outlet 60. The outlet 60 is thus smaller in width/diameter than the width/diameter of the lower chamber 54 or its tubular wall portion 56.

The upper and lower chambers may be of the same lateral, width or diameter, dimension.

Outlet 60 has a tubular shape and may have an outer thread for engaging with a tap connector (or other pipe fitting). Other connector fittings could be provided at the outlet as required. Furthermore, the outlet 60 and/or lower chamber geometry could be modified to provide for different flow regimes and/or flow rates as desired.

The diameter of valve disc/member 48 and/or opening 42 may be less than that for outlet 60 such that the valve spring 50 and/or valve disc 48 may be replaced by removing valve spring clip 52, allowing the lift valve to drop through outlet 60 and out of the connector 10 so that one or more of the components of lift valve may be replaced.

Each of the inlet 12, the opening 42 and outlet 60 may be aligned with the central axis 26. The inlet and opening flow passage 24 are aligned such that water from the inlet flows downwards towards and through the opening 42. The flow passage 24 and opening 42 may be of the same/similar width.

The flow straighteners 22, and/or the distal ends 30 thereof, may be contained within the radial/width envelope of the opening 42 and/or outlet opening 60.

When connected for use, a flow, e.g. a leakage flow, enters the connector 10 through the inlet 12 and collects as a small pool in the middle chamber region at opening 42. When sufficient weight is applied to the valve member 48, the resilient bias of the spring 50 will be overcome and the spring will be deformed/compressed as the valve member 48 and stem 46 move downward. Thus the valve will open and the water can pass through the valve into the lower chamber 54 and through the connector outlet 60.

A viewer can see the water flowing into the upper chamber from the inlet 12 via the gap 20 if present at the time of operation. The gap 20 provides an open window.

Depending on the flow entering the connector 10, a sufficient pool of water may take a shorter or longer time to collect for valve operation. At very low flow rates droplets may be seen dripping from one or more tip of the flow straighteners.

At high flow rates, the presence of the flow straighteners helps ensure a desired (e.g. laminar) flow regime exiting the inlet into the air gap. This can serve to reduce the impact of any downstream obstruction caused by the valve components on the flow regime at the inlet, thereby reducing restriction on flow rate.

It will be appreciated by the skilled person that the flow straighteners described herein could be used for different types of valve present in the connector body. For example duckbill, trap door or skirt valve arrangements could be used in place of the lift valve shown in the figures. Alternatively, the flow straighteners could be used where no valve is present, e.g. in a more conventional tundish connector product. The impact/splashing of flow on the shelving floor of a tundish, and its effect on flow rate/regime at the inlet, may be ameliorated by way of the flow straighteners described herein.

Furthermore it may be desirable to mount other components in the tundish, such as a flow sensor, moisture sensor, temperature sensor or similar. It may be desirable to mount any such component on a strut or other support formation such that it is in the flow path between the inlet and outlet of the connector. The flow straightener of the present invention may therefore be used to help accommodate other potential flow obstructions in addition to, or instead of, a non-return valve.

The flow straighteners may be integrally formed with the inlet or attached thereto,

e.g. as a separate ring component of the inlet.

Different parts of the tundish connector may be formed separately and attached/bonded together, e.g. as threaded parts, using adhesive or else welded,

e.g. friction welded, together. The inlet connector and arms 18 may be formed as a unitary component, e.g. with the flow straighteners. That unitary component may include an upper rim portion of the chamber wall. One or more further components may comprise a middle chamber wall section, e.g. including the shelving floor 40, and/or a lower chamber wall section including the outlet 60.

An advantage of the flow straightener(s) according to various aspects of the invention is that the flow straightener(s) does not encroach into the air gap height of the connector. That is to say, in order to achieve a type AA rating or meet the requirements for the connector to provide an air brake to drain then consideration 10 must be given to the height of the air gap, e.g. with reference to an overspill level of the connector. If the flow straightener effectively reduced the air gap height, then a larger device envelope would be needed to meet the necessary requirements. However the embodiments described herein can meet said requirements without requiring the air gap to be enlarged to accommodate the flow 15 straightener(s).

Claims

1. A connector for a water system, the connector comprising:

an inlet connector, a connector body and an outlet connector arranged in sequence, wherein the connector body is open-sided so as to form a tundish having an open air gap between the inlet and outlet connectors through which water can fall in use, the connector comprising one or more flow straightener arranged to direct flow from the inlet into the connector body.

2. A connector according to claim 1, wherein the inlet connector comprises an inlet flow passage and the one or more flow straightener is located at the inlet flow passage.

3. A connector according to claim 2, wherein the flow straightener extends into and/or along the inlet flow passage.

4. A connector according to claim 2 or 3, wherein the one or more flow straightener takes the form of a wall having a height that is less than a half or a third of the width of the flow passage through the inlet connector.

5. A connector according to any one of claims 2, 3 or 4, wherein the one or more flow straightener is elongate in form and extends in an axial direction with respect to an axis of the flow passage.

6. A connector according to any preceding claim, wherein the one or more flow straightener depends form the inlet connector into the open air gap and has a distal end between the inlet connector and the connector body.

7. A connector according to any preceding claim, wherein the one or more flow straightener is integrally formed with the inlet connector.

8. A connector according to any preceding claim, wherein the one or more flow straightener comprises a rib or prong.

9. A connector according to any preceding claim, comprising a plurality of the flow straighteners.

10. A connector according to claim 9, comprising six or more flow straighteners.

11. A connector according to claim 9 or 10, wherein the plurality of flow straighteners are angularly spaced about a central axis of the connector or the inlet connector thereof.

12. A connector according to claim 9, 10 or 11, wherein the flow straighteners are provided as an annular or circumferential array.

13. A connector according to any preceding claim, wherein the connector body comprises a shelving floor formation between the inlet connector and the outlet connector.

14. A connector according to claim 13, wherein the shelving floor formation divides the interior of the connector body into upper and lower internal chamber portions.

15. A connector according to any preceding claim, comprising a valve located between the inlet connector and outlet connector.

16. A connector according to claim 15, wherein the valve comprises a valve member spanning a valve opening and the flow straighteners extend towards the valve opening.

17. A connector according to any preceding claim comprising a stem, strut or support member located in the flow path between the inlet connector and outlet connector, e.g. depending into the flow path from the connector body.

18. A connector according to any preceding claim, wherein the outlet connector comprises an outlet opening and the flow straighteners extend towards the outlet opening.

19. A connector according to any preceding claim, wherein the inlet connector is supported above the connector body by one or more arms.

20. A connector according to any preceding claim, wherein the one or more flow straightener is tapered towards an end thereof.

21. A connector according to any preceding claim, wherein the one or more flow straightener lies within a radial distance of a central axis of the connector that

5 is less than or equal to a radius of an outlet opening in the outlet connector.