This invention relates to flow regulation in a fluid flow system such as, for example, a fire protection and cooling system for buildings.

Many valves of different types are known for use in fluid flow regulation in fluid flow systems of many different types. In our co-pending Application No. EP 1443277 which was published on 4th August 2004, a number of different valves are described for utilisation for a particular purpose. A pair of release valves are provided which act to allow or prevent water flowing out of the system when a fire is detected to extinguish the fire. Further, cooling control valves are also provided which control the flow of fluid through the cooling pipes of the cooling system. A flow metering/automatic shut-off valve is also described which monitors the flow of water from the fire sprinkler system to a cooling water supply. The valve has two main functions insofar as it monitors and acts on the water supply to ensure that the flow does not exceed a predetermined value. The valve also detects a downstream piping failure and the associated drop in water pressure downstream from it which will therefore enable the valve to fail to a closed position to prevent water damage to building components due to the leak and to prevent loss of system pressure in the upstream piping system.

It is with the latter type of valve that the present invention is concerned. Known automatic shut-off valves used for the above mentioned purpose are usually very complicated in design and construction and therefore can be expensive to a degree sufficient to reduce the likelihood of customers purchasing the valve, or system, due to its cost. The present invention seeks to overcome this problem by providing a simple and inexpensive automatic shut-off valve which involves no reduction in the effectiveness of the valve as compared to known valves for the same use.

In accordance with the present invention, there is provided a fluid flow regulator and automatic flow shut off valve comprising: a valve body having an internal fluid passage chamber and one or more peripheral outlet orifices; a valve head having a fluid inlet orifice at one end and moveable axially relative to the valve body from a fully closed position to a fully open position, thereby correspondingly blocking or unblocking the or each peripheral outlet orifice; a biasing device operable to bias the valve head to move axially towards the fully open position; and a shut off member provided within the fluid passage chamber which blocks passage of fluid from the inlet orifice to the or each outlet orifice when the valve head has moved by a predetermined fraction towards the closed position from the fully open position.

With this arrangement, it is possible to provide a flow regulation device with an automatic shut-off of particularly simple construction and therefore less cost than known valves used for this purpose.

The predetermined fraction may be any suitable fraction towards the fully closed position, In a preferred embodiment, the predetermined fraction may be anywhere between say 40% and 100%. Preferably, the shut off member comprises an axial projection from either the valve body or the valve head. If the shut off member projects from the valve body, it is preferably adapted to abut against the surface valve head surrounding the inlet orifice. If the shut off member projects from the valve head, it preferably projects from the surface of the valve head surrounding the inlet orifice. In this manner, when moved to a shut off position, the shut off member prevents fluid passing from the inlet to the outlets via the chamber.

The distal end of the shut off member may be adapted to provide a seal. In one embodiment, this may be achieved by providing a resilient flexible material around and/or projecting from the distal end of the shut off member.

The shut off member may be a solid projection or may comprise a substantially tubular projection.

Preferably the flow metering characteristics of the valve are related to the size of the orifice through the valve head. Preferably, the or each peripheral orifice may be specially profiled, in operation, to reduce the flow area in accordance with an increase in pressure. This can thus increase the pressure drop across the device whilst retaining a constant flow. The valve head may comprise: an outer portion adapted to engage with the valve body and the biasing device; and a removable plate defining the orifice. In this manner, by exchanging one removable plate having a first sized orifice for another removable plate having a second different sized orifice the controlled flow rate through the valve may be simply and inexpensively varied.

Preferably the biasing means comprises a resilient spring, which may be of helical form. Most preferably the biasing device is provided around the outside of the shut off member. Preferably a seal is provided between the valve body and the valve head to prevent fluid leakage from the body. The seal may comprise a skirt of elastomeric material.

Preferably, the valve is adapted to be utilised in a combined fire protection and cooling system for a building. The invention will now be described further by way of example only and with reference to the single figure of the drawing:

Referring now to Fig. 1 there is shown a valve 10 for regulating the flow of fluid through a fire protection and cooling system for buildings. The valve 10 comprises a valve body 11 and a valve head 12 moveable axially within the valve body 11. Movement of the valve head 12 within the valve body 11 results in the blocking or unblocking of one or more peripheral orifices 15, thus partially or fully closing or opening the valve 10. The peripheral outlet orifices are specially profiled to give a linear flow characteristic against varying pressure. The valve head 12 is biased towards an open position relative to the valve body 11 by a resilient biasing spring 13. In normal steady state operation the valve head 12 and body 11, are biased away from each other under the action of the spring 13 into a fully open position.

An elastomeric skirt 9 is provided between valve body 11 and valve head 12. The elastomeric skirt 9 acts as a seal preventing fluid passing through the gap between valve body 11 and valve head 12.

Valve head 12 has comprises an outer portion which engages with the valve body 11 and a removable plate 19. The removable plate has an opening 20 provided therein which defines an inlet orifice for the valve 10. An 'O' ring seal 18 is provided between the removable plate 19 and the valve head 12 to prevent leakage into the chamber. The removable plate 19 is interchangeable with other removable plates 19 providing different sized openings thus allowing different flow rates to be controlled through the valve 10. The inlet orifice 20 sets the fiowrate whilst the specially profiled peripheral orifices 15 provide the linear control of the rate itself. The biasing spring 13 extends between the valve head 12 and valve body 1 1 around shut off member 14 projecting axially from the valve body 11. The member 14 is adapted in use to abut a valve seat 16 provided by removable plate 19 around opening 20 when the valve head has moved a predetermined fraction from fully open to fully closed. In this manner, member 14 can restrict flow through inlet orifice 20. For example, in one embodiment, the member 14 may abut the valve seat 16 when the valve is 40% closed. Of course, the arrangement of the valve seat 16 and valve body 11 can be arranged such that the member 14 abuts the valve seat 16 when the valve 10 is closed to any desired proportion as desired or as appropriate. The member 14 may be provided with a seal 17 around its distal end. The seal

17 is typically formed of a resilient flexible material and thus acts to prevent leakage of fluid from valve 10. The seal 17 is may optionally be omitted, In such cases, some leakage of fluid will occur. This can actually assist in certain circumstances in rendering the resetting of the valve 10 after closure more easy to undertake. When mounted in a pipe carrying fluid, for example, water, the fluid flow through the valve is in the direction of arrows A, B and C. In response to a loss of pressure downstream from the valve 10, the valve 10 closes. This is achieved by the valve head 12 being drawn towards the valve body 11 against the biasing of the spring 13. If the pressure loss is sufficient, the shut off member 14 abuts the valve seat 16 shutting off flow through the valve completely. By arranging the dimensions of the shut off member 14 and the seat 16, as well as the valve body 1 1 and head 12, it is possible for the valve 10 to maintain a steady flow in normal operation and, in response to detection of sufficient loss of pressure, to shut off thereby preventing damage to downstream components. For example, in a typical configuration, by appropriate configuration of the items mentioned, it is possible for the valve to be shut off in response to a movement of anywhere between 40% and 100% of the distance between the fully open and fully closed positions.

It can be seen that the valve of the invention, as described above, is very simple in constructions consisting essentially of a very small number of parts. This means that the manufacturing of the valve is very much simpler and the cost of the finished item will be considerably less expensive than those known valves for the purpose for the invention is intended.

In use, valve 10 of the invention can be disposed in the pipe network of, for example, fire protection and cooling system for a building of the type described in the above mentioned co-pending Application No. EP 1443277 published on 4 August

2004. Thus and for example, the valve 10 of the invention can be provided in a cooling water supply shown leaving the combined fire sprinkler/cooling system as described in the above mentioned specification or the valve can be utilised in any other position as desired or as appropriate where fluid flow regulation is required.

In such an embodiment, the valve 10 may be set up to operate under any suitable range of pressures and/or flow rates, Typically, in such systems, the valve 10 may be adapted to operate in a pressure range between say lOKpa and 600Kpa. It is of course clear to the skilled man that adjustments to this specification would and could be made for use in other systems.

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiment which is described by way of example only.