WO2012110784A1

WO2012110784A1 - Air break

Info

Publication number: WO2012110784A1
Application number: PCT/GB2012/050274
Authority: WO
Inventors: Richard DENBURY; David Beale
Original assignee: Wallgate Limited
Priority date: 2011-02-18
Filing date: 2012-02-08
Publication date: 2012-08-23
Also published as: GB201102881D0

Abstract

An air break is disclosed comprising a water inlet for connection to a water supply, a water outlet for connection to a wafer outlet pipe, at least one air inlet situated between the water inlet and the water outlet, and an outlet flow restrictor. Preferably, the outlet flow restrictor comprises a tapered inset situated, in use, in the water outlet or water outlet pipe. The air break preferably further comprises a shroud adapted to cover the air inlet(s). The air break of the invention advantageously prevents back flow in water systems, in particular, portable water systems.

Description

AIR BREAK

The present invention relates to air breaks. In particular, the present invention relates to air breaks for use in water supply pipes, especially potable water supply pipes.

The water supplied to sanitary ware is often potable water. If such potable water is supplied to sanitary ware such as W.C.s then it is very important that backfiow of water from the sanitary ware to the (potable) water supply does not occur.

In domestic water systems there are air gaps above the water level in a cistern which prevent backfiow into the supply. However, in communal water systems and, in particular, in institutions (such as secure institutions, for example prisons), water supply to sanitary ware is often direct (albeit through valves) without the use of an individual cistern for each item of sanitary ware.

British Standard BS EN 14453:2005 relates to devices to prevent backfiow of potable water.

GB-A-2 ,433,885 discloses a shower assembly for use in a medical environment. However, in this system the water supply is not direct from above and so is relatively iow pressure. This document also does not apply to sanitary Ware such as sinks or WCs where too much water flow and/or aeration is inconvenient.

There is, therefore, a need to provide a system to prevent backfiow which is generally applicable in water systems and which overcomes the problems of the prior art.

It is an aim of the present invention to address this need.

The present invention according provides an air break comprising, a water inlet for connection to a water supply, a water outlet for connection to a water outlet pipe, at least one air inlet situated between the water inlet and the water outlet, and an outlet flow restrictor.

Usually the air break is adapted so that the water supply is situated above the water inlet, in use. Preferably, the outlet flow restrictor comprises a tapered insert that is situated, in use, in the water outlet or water outlet pipe, Usually, the tapered insert tapers out from the air inlet side (or the water inlet side) of the air break to the water outlet side (i.e. is relatively narrow at the air inlet side and relatively wide at the water outlet side) in order to smoothly restrict the flow of the water and/or air drawn in from the air inlet(s) and thereby reduce flow and/or aeration of the water. This is advantageous because it reduces splash in the sanitary ware that is to be connected to the water outlet pipe. Most preferably, the tapered insert (or at least a portion of the tapered insert) is substantially conical.

The air break will usually be adapted to fit a water supply pipe having a smaller diameter than the water outlet pipe.

Preferably, the restrictor is of a size such that the flow of water through the water outlet pipe is restricted to 1 to 3 litres/second, preferably 1.5 to 2.0 litres/second.

The air break will usually comprise at least three air inlets, which are preferably evenly distributed around the body of the air break. Therefore, there will usually be 4, 5, 6 or 7 air inlets or more. Generally, where the diameter of the restrictor is wider (thereby restricting water flow more) the more air inlets there are. It is advantageous if the diameter of one or more of the air inlets is adapted to provide sufficient air flow into the air break- If more air flow is required, the diameter of the air inlet or one or more air inlets may be increased.

Preferably, the water inlet comprises a nozzle having a tapered portion. This is advantageous because it reduces the turbulence of flow of the water into the air break, which reduces spray of water out of the air iniet(s). Consequently, the tapered portion will usually narrow from the water supply side to the at least one air inlet or the air inlet side. Generally, the nozzle aperture is of a suitable diameter or size to enable the flow rate of water to be sufficient.

The air break according to the invention will usually further comprise a shroud adapted to cover the air inlet(s). This is advantageous because it reduces debris blocking the air inlet(s) and can direct downwards any water which comes out of the air inlets.

By way of an example, embodiments of the invention will now be described with reference to the accompany drawings in which:

Figure 1 illustrates the air break according to the invention in a water supply line,

Figure 2 illustrates the air break body, and

Figure 3 illustrates the restrictor and its component parts.

Figures 1 (a), (b) and (c) illustrate an air break 2 according to the invention situated, in use, and connected to a water supply pipe 6 at the inlet of the air break 2 and a water outlet pipe 12 connected to the outlet of the air break 2. The outlet pipe 12 wi!l, usually, be connected to an item of sanitary ware (e.g. a WC or other device).

Figure 1(b), illustrating a magnified portion of Figure 1(a) at A, shows that the air break 2 comprises an air break body 16 and that the water supply pipe 6 is engaged with the inlet of the air break 2 and firmly fixed using compression nut 14. Shroud 4 is situated on the air break 2 in order to direct downwards any water which is released through air inlet holes 18 (referring to Figure 1c). Shroud 4 is designed to snap-fit on the air break body 16.

Figure 1c illustrates a section on B B of Figure 1b. Figure 1c shows that the water supply pipe 6 is Inserted into the inlet portion of the air break 2 and sealed in place using olive ring 20 and, as previously discussed, compression nut 14. Water will flow through water supply pipe 6 and into the air break 2 through funnel portion 24 which acts to improve the laminar flow of the water and reduce turbulence. This is particularly important because below funnel portion 24 in the main cavity 25 of the air break body 16 are air inlet holes 18 which are open to ambient pressure. Water will not flow out of the air holes in normal operation but only if a back flow of water reaches the air holes. If this does occur, shroud 4 directs downwards any water. Shroud 4 also reduces blockage of the air inlet holes 18 by deposits. The air break 2, ensures there is an air gap between the bottom of the supply pipe 6 around the funnel portion 24 of the air break 2 and around the start of the outlet pipe 12 situated on the outlet side of the air break. Because the air inlet holes 18 communicate with the air, the result is that the air break 2 prevents back flow or siphoning action if there is suction above vaive 10 in the water supply line. This is important because the water supplied through pipe 6 is often potable water and it is important that water which is intended for e.g. a WC, does not flow back into the potable water supply,

Restrictor cone 9 fixed to restrictor body 7 and inserted into the outlet portion of the air break 2 acts to reduce the flow of water, reduce the amount of turbulence and reduce the amount of air incorporated in the water supply through supply pipe after passing through the air break 2. This is particularly important if the water outlet pipe 12 is to lead to a sanitary device such as WC or sink because it reduces the amount of aeration In the water supplied to that device and hence the amount of spray in the device. The water outlet pipe 12 is seaiingiy connected within the air break body by use of "0" ring 22.

Figure 2 illustrates the air break body in more detail, Figure 2a is a schematic of the body with Figure 2b being a section on B - B of Figure 2a. Figure 2 shows the funnel portion 24 leading into the main cavity 25 of the air break body 16. In the main cavity 25, air inlet holes 18 tead to atmosphere. "0" ring seat 23 is situated towards the bottom of the air break body in order to incorporate an "0" ring. As illustrated in magnified portion A the edges of the air break body 16 are generally chamfered.

Figure 3 illustrates the restrictor in more detail. Restrictor 26 comprises a restrictor body 7 and a restrictor cone 9. Restrictor cone 9 is fixed into the restrictor body 7 using the dowel pins 8, The holes through which the dowel pins pass in both the restrictor body 7 and the restrictor cone 9 are off-set one to the other so that pins may pass over one another without clashing within the restrictor body 7. The restrictor body, once assembled, is inserted into the bottom portion of the air break body in order to sit within the water outlet pipe 12 in use. The restrictor 26 may, of course, be constructed in other ways, for example by injection moulding. 2 Air break

4 Shroud

6 Water supply pipe 7 Restrictor body 8 Dowel pin

9 Restrictor cone 10 Flush valve 12 Outlet pipe 14 Compression nut 16 Air break body 18 Air inlet hole(s) 20 Olive ring

22 'Ο' ring

23 Ό' ring seat 24 Funnel portion 25 Main cavity 26 Restrictor

Claims

CLAIMS 1. An air break comprising,

a water inlet for connection to a water supply,

a water outlet for connection to a water outlet pipe,

at least one air inlet situated between the water inlet and the water outlet and

an outlet flow restrictor.

2. An air break as claimed in claim 1, wherein the water supply is situated above the water inlet, in use.

3. An air break as claimed in either claim 1 or claim 2, wherein the outlet flow restrictor comprises a tapered insert situated, in use, in the water outlet or water outlet pipe.

4. An air break as claimed in claim 3, wherein the tapered insert tapers out from the air inlet side of the air break to the water outlet side.

5. An air break as claimed in either claim 3 or claim 4, wherein at least a portion of the tapered insert is substantially conical,

6. An air break as claimed in any one of the preceding claims adapted to fit a water supply pipe having a smaller diameter than the water outlet pipe.

7. An air break as claimed in any one of the preceding claims, comprising at least three air inlets.

8. An air break as claimed in any one of the preceding claims, wherein the water inlet comprises a nozzle having a tapered portion.

9. An air break as claimed in claim 8, wherein the tapered portion narrows from the water supply side to the air inlet side.

10. An air break as claimed in any one of the preceding claims further comprising a shroud adapted to cover the air inlet(s).