FIELD OF THE INVENTION

The present invention relates to a plumbing tundish, which facilitates removal of discharge, from a pressure relief valve, associated with a fresh water system, to waste whilst eliminating the risk of backflow contamination of the fresh water system

BACKGROUND TO THE INVENTION

A tundish is a device that can be used to visualise a fault in for example an unvented domestic hot water storage system or an unvented hot water heater. Such systems are typically supplied with a pressure relief valve (PRV) or temperature relief valve (TRV) to allow them to vent when pressure or temperature within the system reaches a predetermined level.

When the water within the hot water storage system or water heater is heated, steam is created, which results in increased pressure within the system. At a predetermined pressure, for example 5 bar, the function of the PRV is triggered such that it opens to relieve the pressure within the system. The relief is due to the expulsion of the steam from the system via the PRV. The steam condenses on the end of the PRV and the resulting water drips into a tundish that is connected to the PRV.

The inlet end of a tundish device is connected to the outlet side of the PRV and any discharge from the PRV drips or flows into the tundish.

The outlet end of the tundish is arranged to discharge any water to waste. Backflow from waste is prevented by an air gap provided near the top of the tundish; the air gap also assists with visualising any discharge via the PRV. It will be appreciated that any backflow is undesirable because the system to which the tundish is connected typically contains fresh, clean water and backflow could contaminate the water being supplied from the tank if not prevented.

A known tundish incorporates an air gap in the upper portion of the body which allows fluid flow through the tundish but prevents back flow of fluids and additionally incorporates a one-way valve, which is operable to prevent backflow of fluid and of odours from the outlet side of the tundish.

It is desirable to provide an improved plumbing device, which incorporates the function and operation of a tundish. SUMMARY OF THE INVENTION

Accordingly, the present invention provides a plumbing device comprising a hollow tubular body, wherein the body comprises a first hollow connector and a second hollow connector, wherein the first and second hollow connectors are detachably connected to each other, wherein when connected the first and second hollow connectors form a tundish device, wherein the first connector comprises an air gap, which is defined by a plurality of elongated windows, arranged in at least two rows comprising a grid arrangement, which is configured by a plurality of substantially horizontal and a plurality of substantially vertical members, wherein points of intersection of the substantially horizontal and the substantially vertical members, define corners of each window.

The elongated form of the windows and the arrangement of the grid cumulatively provides a relatively large air break and provides a visual indicator if/when something is wrong with the system in which the device is installed. The arrangement of the grid formation IS SUCh that fingers cannot access the flow area defined by the tubular body; this is particularly important when discharge fluid passing through the tundish device is steam or hot water and there is a risk of scalding.

The grid and window arrangement provide a relatively large volume air gap/air break to prevent backflow and facilitate observation of any fluid flow through the tubular body.

The grid may comprise at least one substantially horizontal member and a plurality of substantially vertical members distributed along the horizontal member, thereby defining the plurality of intersection points and the plurality of windows arranged in at least two rows. The first and second hollow connectors may each comprise an inlet end and an outlet end, wherein the inlet end of the second hollow connector facilitates connection of the second hollow connector to the outlet end of the first hollow connector and the inlet end of the second hollow connector facilitates receiving a non-return valve device within the second hollow connector and wherein the inlet end of the first hollow connector provides the inlet end of the assembled tundish device and the outlet end of the second hollow connector provides the outlet end of the assembled tundish device.

The inlet end of the second hollow connector may comprise a rim upon which a collar of a non-return valve device rests upon insertion into the second hollow connector and wherein connection of the first hollow connector to the second hollow connector interact to secure the collar of the valve device between the first and second hollow connection and the valve device within the second hollow connector.

The collar may include a lip configured to be received on the rim of the second connector prior to assembly of the first and second hollow connectors. Assembling the first and second hollow connectors to produce an assembled tundish device is operable to retain the non-return valve device within the second hollow connector, wherein the first connector may be operable to push the lip against the rim thereby sandwiching the lip between the first and second hollow connectors. Connection of the first hollow connector to the second hollow connector may secure the valve device within the tubular body and may secure the collar against the rim of the second hollow connector.

Connection of the first hollow connector to the second hollow connector may be mechanical fastening, wherein the outlet end of the first hollow connector is mechanically fastened to the inlet end of the second hollow connector.

The mechanical fastening may be by threaded connection. Alternatively, the outlet end of the first hollow connector and the inlet end of the second hollow connector may include a bayonet connection or a snap-fit connection.

The valve device may comprise a duckbill valve extending down from the collar into the second hollow connector, wherein the duckbill valve comprises an elongated hollow body, which includes an open first end, an open hollow section extending from the open first end, a flattened section extending from the open hollow section to a normally closed second end, wherein the flattened section and the normally closed second end are operable to allow one-way downstream fluid flow in a direction from the open first end to the normally closed second end and to prevent upstream backflow fluid and backflow odours from a direction downstream of the second closed end towards the open first end.

A tundish device comprising detachable first and second hollow connectors according to an embodiment of the present invention provides a versatile tundish device where the device can be used with or without a valve. For example, in a location where back odours are not a concern a valve may not be necessary and the assembled tundish device can be used as a simple straight tundish. In a location, where back odours, for example sewer smells, are a concern the tundish device can be fitted with a valve which allows flow through the device from inlet to outlet, but prevents back flow from outlet to inlet.

The ability to assemble a tundish device of two connectable hollow connectors also provides versatility in changing either or each of the connectors where the end fitting of the inlet end of the first hollow connector and the outlet end of the second hollow connector may be larger or smaller than conventional.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 illustrates a schematic representation of an assembled tundish device according to an embodiment of the present invention;

Figure 2 illustrates a schematic representation of a cross-sectional view of the tundish device of figure 1 including a non-return valve located inside the tundish;

Figure 3a illustrates a front view of a duck-bill type non-return valve as used with an embodiment of the present invention; and Figure 3b illustrates a side view of the duck-bill valve of figure 3a showing the normally closed arrangement.

DESCRIPTION Referring to figure 1 and figure 2, the illustrated tundish 10 comprises a hollow tubular body 12 (see figure 2) formed of an upper connector 14 and a lower connector 16. The upper connector 14 provides the inlet to the tundish 10 and the lower connector 16 provides the outlet from the tundish 10. The tundish 10 is typically installed in a vertical orientation as illustrated. Therefore, references to the illustrated parts as upper and lower parts is based on the orientation, as illustrated, and as intended for installation.

In the illustrated example, an inlet end 15 of the upper connector 14 includes an external threaded connector 18, which facilitates connection of the assembled tundish 10 to a suitable pressure relief valve or temperature relief valve (not illustrated). The lower connector 16 also includes an external threaded connector 20 at the outlet end 21 , where the threaded connector 20 facilitates connection of the assembled tundish 10 to a suitable waste system (not illustrated).

The assembled tundish 10 requires connection of the upper connector 14 to the lower connector 16. In the illustrated example, the connection of the upper and lower connectors 14, 16 is by threaded connection, where the upper connector 14 includes an outlet end 22 comprising an internal thread and the lower connector 16 comprises an inlet end 26 (see figure 2) comprising an external thread. When assembling the tundish 10, the inlet end 26 of the lower connector 16 is received in the outlet end 22 of the upper connector 14.

Alternative arrangements of connecting the upper and lower connectors may include a bayonet connection (not illustrated), a snap fit connection (not illustrated) etc.

The upper connector 14 includes an air break 30 proximate the inlet end 15. The air break 30 includes a grid arrangement 32, which, in the illustrated embodiment, includes vertical members 34 and horizontal members 36 arranged to define windows 35 between the intersection points of the vertical and horizontal members 34, 36.

The grid arrangement 32 provides an efficient air break 30 which prevents a backflow of fluid and enables a visual check for discharge from the system to which the tundish assembly 10 is connected.

The windows 35 provide ventilation, which creates an effective air gap or air break and the spacing defined by the grid arrangement is small enough to prevent access to the inside of the body 12, for example by fingers, whilst the tundish 10 is assembled. This is particularly important when the tundish 10 is connected to a boiler or hot water system, where it will be appreciated that any discharge may be scalding hot.

Referring to figures 2, 3a and 3b, the tundish assembly 10 includes a non-return valve 38. In the illustrated example the non-return valve comprises a duck-bill valve, but it will be appreciated that other valve types may be used.

The non-return valve 38 is mounted within the body of the tundish 10 via the inlet end 26 of the lower connector 16.

In the illustrated example, the non-return valve 38 is mounted within the lower connector 16. The non-return valve 18 is carried in a collar 40. The collar 40 comprises a lip 42 at the upper end. The lip 42 is configured to rest on a rim 44 at the upper inlet end 26 of the lower connector 16 to locate the non-return valve 38 within the tubular body 12.

The arrangement of the lip 42 and the rim 44 facilitates retaining the non-return valve 38 within the tubular body 12, wherein assembling the upper and lower connectors 14, 16 compresses the lip 42 between an inner surface or shoulder (not illustrated) provided on the inside of the outlet end 22 of the upper connector 14 and the rim 44 of the lower connector 16.

The outer surface of the collar 40 may be ribbed 43 to create an interference fit when it is inserted in the lower connector 16. Alternatively, or in addition the collar may comprise a seal (not illustrated), such as an O-ring seal on the outer surface of the collar 40 such that sealing contact is created between the exterior of the collar 40 and the interior of the lower connector 16 during assembly.

It will be appreciated that the non-return valve acts to prevent backflow of fluid and odours from the outlet end 21 to inlet end 15 of the assembled tundish 10. Referring to figures 3a and 3b, in the illustrated example, the duck bill valve 38 includes a collar 40 and a valve member 50. The valve member 50 is manufactured from rubber or a synthetic elastomer. The upper portion of the valve member (the inlet side) is held open by a substantially cylindrical member 52 and the outlet end 54 is shaped and formed to be flattened. When fluid or pressure acts on the valve member 50 from the inlet side, the pressure acts to open the outlet end of the valve member 50 to allow fluid or gas to pass through the valve member 50. When pressure is removed, the outlet end 54 of the valve member 50 returns to the flattened, closed configuration and remains closed, particularly if pressure from the outlet end 54 acts on the valve member 50. In the illustrated example, the shape of the substantially cylindrical support at the inlet end of the valve member prevents the valve member 50 from inverting when subject to pressure from the outlet side 54 of the valve member 50. In the illustrated example, the substantially cylindrical support comprises two diametrically opposite V-grooves 52 substantially the height of the cylindrical support. The voids created by the grooves define the substantially cylindrical support as two diametrically opposed curved inverted V-members which hold open the upper body of the valve member 50. The support arrangement is such that in the event of back pressure the inverted V- members oppose inversion of the valve member 50. In the illustrated example, the closed end 54 of the valve member 54 includes a kinked section 60 such that backflow pressure or fluid will tend to fold the valve member 50 about itself rather than open the valve member 50. The inverted V-members act to limit folding of the valve member 50 in this situation also.

The provision of a two-piece tubular body is such that the tundish 10 can be maintained and the non-return valve 38 can be replaced if faulty or is of insufficient flow rate to allow full discharge.

The main function of the non-return valve 38 in the tundish assembly is to prevent backflow of odours, for example from the waste conduit located downstream of the tundish assembly 10. Accordingly, a tundish assembly 10, according to an embodiment of the present invention, is versatile in that the upper and lower connectors 14, 16 can be substituted with similar upper and lower connectors to accommodate available space in the installation system or dissimilar connector dimensions upstream and downstream of the device.

It will be appreciated, the tundish assembly 19, according to an embodiment of the present invention, can be used with or without a valve member 38 or with an alternative valve member to that described above. For example, a diaphragm valve or a spring- loaded valve member could be inserted. Expected flow conditions may dictate what type of valve is best suited to the tundish assembly 10. The modular arrangement of the tundish assembly 10, according to an embodiment of the present invention is such that a maintainable product is provided rather than a consumable product.

Whilst specific embodiments of the present invention have been described above, it will be appreciated that departures from the described embodiments may still fall within the scope of the present invention.