AU750034B2 - Anti-water hammer device - Google Patents

Description

EDITORIAL NOTE NO. 67101101 This specification does not contain a page numbered 1.

2 Anti Water Hammer Device FIELD OF THE INVENTION The present invention relates to a device for reducing water hammer in pipes carrying water.

BACKGROUND OF THE INVENTION The problem of water hammer in pipes carrying water is well known. The sudden stopping or ceasing of a water flow through the rapid closing of a valve causes a steep fronted pressure wave to move through the pipe. This results in pipe vibrations and associated noise.

The use of solenoid valves in domestic washing machines causes a particularly acute demonstration of the problem although water hammer can occur throughout a water supply system wherever a long flow pipe exists.

The vibration and noise that characterises water hammer is not merely a nuisance to the householder but can influence the longevity and functioning of any of the 1: 5 components of a water supply affected by the hammer. It is therefore desirable that water hammer is avoided or that the effects of water hammer are reduced.

The apparatus of the present invention provides a means of reducing the physical S. impact of a water hammer causing pressure front on plumbing pipes SUMMARY OF THE INVENTION 20 Therefore, according to the invention there is provided apparatus adapted for in line connection to a pipeline carrying fluid, said apparatus including a flexible connector located within a housing, said flexible connector having an inner bladder having resilient walls and an outer flexible casing of braided material and wherein fluid passing through the flexible connector travels through a non-linear path.

The apparatus of the present invention therefore provides two independently f-kictioning mechanism for the reduction of pressure in a wave front associated with 3 water hammer in pipes, namely, the walls of the flexible connector and the path for the fluid in the connector within the housing.

Preferably, the flexible connector is attached at opposing ends thereof to the housing and wherein the length of the connector is greater than the length of the housing thereby ensuring that fluid in the connector travels through a non-linear path.

Preferably, the braided material consists of braided metallic strands.

Preferably, the flexible connector attached to the housing at opposing inlet and outlet ends by means of threaded inlet and outlet connectors that are secured in a wall of the housing and to which the flexible connector is connected. In such a case, the threaded inlet and outlet connectors are each secured in position with respect to the housing by means of a pair of locking nuts, a respective locking nut being located internally and externally of the housing.

In a preferred embodiment of the invention, the apparatus further includes a pressure •limiting valve within the housing and in line with the flexible connector, the pressure 15 limiting valve being located upstream of the flexible connector. Pressure limiting valves that operate at pressures up to 2000 KPa have been found to be convenient.

Preferably, the housing is a 100mm diameter PVC sewer pipe. Further, the housing is preferably closed at either end by caps serving to allow access to the interior of the housing so that the apparatus can be assembled and disassembled as required.

20 It is also possible for the housing to includes a conical sleeve filled with a sealant material that covers the externally located parts of the apparatus thereby preventing any unwanted material finding its way into the interior of the housing and/or the housing may include a section of closed cell foam plastics material serving as a pressure compensator.

\DESCRIPTION OF DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate a preferred embodiment of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the 4 Figure 1 illustrates a first cross-sectional view of an apparatus in accordance the present invention; and Figure 2 illustrates a second cross-sectional view of the apparatus of figurel showing the assembly in greater detail.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings illustrate an apparatus 10 adapted for in line connection into a pipeline 12 carrying fluid. It is envisages that the paratus 10 would in general use be connected to a domestic mains water supply upstream of any outlet points for household use. Thus, the apparatus can be installed at any point on the residence side of a domestic water meter.

The apparatus 10 includes a fluid inlet connector 14 including, in this example, a pressure-limiting valve 16 arranged for connection in the pipeline 12, and a flexible connector 18. A fluid outlet connector 20 is located downstream of the flexible connector 18. It can thus be seen that the flexible connector 18 forms, in situ, a section oooo 15 of the pipeline 12 running between the fluid inlet connector 14 and the fluid outlet connector 20. The fluid inlet, 14 flexible connector 18 and fluid outlet connector 20 are S housed in an outer housing 22. The housing 22 serves generally as a means to protect o. •the flexible connector 18 from the surrounding environment and also as a means to readily identify the apparatus of the invention after installation. The housing is sealed by and allows the apparatus 10 of the invention to be installed in any position in a pipeline considered convenient or desirable. For example, the apparatus 10 con be installed in section of pipe running horizontally, vertically or at any angle therebetween, and above or below ground as circumstances require.

Each of the fluid inlet connector 14 and fluid outlet connector 20 take the form of a threaded brass running nipple secured to respective outer ends of the housing 22.

*00 C The position of the fluid inlet connector 14 with respect to the housing 22 is secured by means of a pair lock nuts 24 and associated washers 26 located one internally within the housing and a second lock nut 24 and washer 26 located externally of the housing 22. The fluid outlet connector 20 at an opposite end of the housing 22 is similarly secured to the housing by a further pair of lock nuts 24 and washers 26.

The pressure limiting valve 16 is located inline with the fluid inlet connector 14 and upstream of the flexible connector 18. The pressure limiting valve 16 is adapted so as to be able to take inlet pressures of up to 2000 KPa and operates up to 80 C. The valve 16 is of a commercially available type and includes an inlet closable by a piston operated on a spring (mechanism not shown). The pressure limiting valve has a fixed outlet pressure of 500 KPa.

In the embodiment shown a reducing socket 28 is located between an outlet side of the pressure limiting valve 16 and an inlet side of the flexible connector 18. The flexible connector 18 is a tube like member and includes an inner lining in the form of a rubber bladder and an outer, braided casing 30. The braided casing 30 is formed of interwoven metallic strands.

A further reducing connector 34 connects the flexible connector 18 to the fluid outlet connector As shown in figure 1, the flexible connector 18 is in fact longer than the housing 22.

S.46. Thus, in order for the fluid inlet connector 14 and the fluid outlet connector 20 to be secured in the housing 22 it is necessary that the flexible connector 18 is slightly ese..

compressed, or at least that connector 18 does not lie in a straight line but adopts a S slightly wavelike formation as shown in the drawings. Water, or fluid travelling through the apparatus 10 is therefore forced to travel in a path that deviates slightly from the direction of the pipeline 12.

Thus, any water entering the through the fluid inlet connector 14 first encounters the ••pressure limiting valve 16. The valve 16 does not function does not function as a precise pressure regulator but is sufficiently able to limit any overpressure in the o system. Fluid then encounters the flexible connector 18 and any remaining excess pressure is absorbed by the bladder and the braided outer casing 30. In the flexible connector 18 the fluid travel through a non-linear path established as a result of the compression of the flexible connector in the housing. At the fluid outlet connector any pressure front is dissipated such that the possibility of water hammer in the pipe 12 is substantially reduced.

The housing 22 is a 100 mm diameter PVC sewer pipe. This is closed at either end by caps 36. The caps 36 serve to allow access to the interior of the housing 22 so that the apparatus can be assembled and disassembled as required. It can also be seen that a 6 conical sleeve 38 filled with a sealant material 40 covers the externally located parts of the fluid inlet connector 14 and fluid outlet connector 20. The sealant 40 serves to prevent any unwanted material such as soil or moisture from finding its way into the interior of the housing 22. The housing further includes a section of closed cell foam plastics material 42 serving as a pressure compensator.

Although the invention has been described with reference to use of the apparatus of the present invention in domestic situation it should be realised that the invention is of more general applicability to the flow of fluids through pipes and the invention may find application in industrial or commercial uses.

Other modifications may be made to the present invention without departing from the scope of the invention. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

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Claims (12)

1. An apparatus adapted for in line connection to a pipeline carrying fluid, said apparatus including a flexible connector located within a housing, said flexible connector having an inner bladder having resilient walls and an outer flexible casing of braided material and wherein fluid passing through the flexible connector travels through a non-linear path.

2. An apparatus according to claim 1, in which the flexible connector is attached at opposing ends thereof to the housing and wherein the length of the connector is greater than the length of the housing thereby ensuring that fluid in the connector travels through a non-linear path.

3. An apparatus according to claim 1 or claim 2, in which the braided material consists of braided metallic strands.

4. An apparatus according to any one of the preceding claims, in which the flexible connector attached to the housing at opposing inlet and outlet ends by means of 15 threaded inlet and outlet connectors that are secured in a wall of the housing and to which the flexible connector is connected.

An apparatus according to claim 4, wherein the threaded inlet and outlet connectors are each secured in position with respect to the housing by means of a pair of locking nuts, a respective locking nut being located internally and externally of the housing.

6. An apparatus according to any one of the preceding claims, in which the apparatus further includes a pressure limiting valve within the housing and in line with the flexible connector, the pressure limiting valve being located upstream of the flexible connector.

7. An apparatus according to claim 6, in which the pressure limiting valves operates at pressures up to 2000 KPa.

8. An apparatus according to any one of the preceding claims, wherein the housing is ,100 mm diameter PVC sewer pipe. 8

9. An apparatus according to any one of the preceding claims, wherein the housing is closed at either end by caps serving to allow access to the interior of the housing so that the apparatus can be assembled and disassembled as required.

An apparatus according to any one of the preceding claims, wherein the housing additionally includes a conical sleeve filled with a sealant material that covers the externally located parts of the apparatus thereby preventing any unwanted material finding its way into the interior of the housing.

11. An apparatus according to any one of the preceding claims, in which the housing further includes a section of closed cell foam plastics material serving as a pressure compensator.

12. An apparatus as defined in claim 1, substantially as hereinbefore described and as illustrated in the accompanying drawings. Dated this 16th day of May 2002 Malcolm Charles Robertson and Yvonne Coral Robertson i By their Patent Attorneys Lesicar Perrin .oo