"FIRE SPRINKLER SYSTEM"

Field of the Invention

The present invention relates to a fire sprinkler system for domestic buildings and to various components of such a fire sprinkler system. The invention is intended particularly but not exclusively for use in domestic dwellings such as homes.

Background to the Invention

Fire sprinkler systems have long been installed in most commercial and industrial buildings as an important element of fire protection systems, together with smoke and heat detectors, fire alarms, fire escapes, fire hydrants and fire extinguishers. In fact, in many jurisdictions, commercial and industrial buildings are required by law to have fire sprinkler systems installed. Many domestic dwellings are now also being fitted with smoke and heat detectors and fire alarms. However surprisingly few, if any, domestic dwellings are fitted with fire sprinkler systems. There are various reasons for this, cost being only one of the factors that has militated against their more widespread use. Another factor is the difficulty of ensuring that a sufficient volume and pressure of water is always available to a domestic fire sprinkler system. This is a problem as domestic dwellings cannot be connected to the high pressure fire department water supply, and therefore must be supplied from the ordinary mains water supply.

The invention was developed with a view to providing a domestic fire sprinkler system that is suitable for connection to an ordinary mains water supply.

References to prior art in this specification are provided for illustrative purposes only and are not to be taken as an admission that such prior art is part of the common general knowledge in Australia or elsewhere.

Summary of the Invention

According to one aspect of the present invention there is provided a fire sprinkler system for connection to a mains water supply in a domestic dwelling or other building, the system comprising:

a plurality of sprinklers adapted to be mounted in a ceiling of the building;

a fire system water supply line for supplying water to said plurality of sprinklers; and,

a sprinkler priority valve, adapted to be mounted in close proximity to a water supply authority water meter, for diverting the bulk of the water from the mains water supply to the fire system water supply line whereby, in use, sufficient water is available at an adequate volume and pressure to feed the sprinkler system in the event that a sprinkler is activated.

In one embodiment said sprinkler priority valve comprises a diverter chamber having a water inlet for receiving water from the mains water supply, a first outlet for directing water to the fire system water supply line, and a second outlet for directing water to a domestic water supply line, and wherein in the event that a sprinkler is activated said diverter chamber diverts the bulk of the water from the second outlet to the first outlet.

In another embodiment said sprinkler priority valve further comprises a solenoid activated shutoff valve for closing the second outlet in the event that a sprinkler is activated, so that all of the water from the water inlet is diverted to the first outlet.

In a further embodiment said diverter chamber in the sprinkler priority valve comprises a slidable piston which is movable between a first position in which the first outlet is closed and a second position in which the first outlet is open.

The fire sprinkler system may further comprise a non-return valve in the fire system water supply line, the non-return valve having a built-in flow sensor for detecting the flow of water through the valve and generating a sensing signal in response to the detection.

Preferably the fire sprinkler system further comprises a stop cock for temporarily isolating the fire sprinkler system from the mains water supply.

The stop cock preferably comprises:

an inlet for connection to the mains water supply;

an first outlet for connection to the fire sprinkler system, the first outlet having a wall to block the flow of water from the mains water supply to the fire sprinkler system; and,

a bleed valve for flushing the mains water supply of dust and other contaminants prior to connection to the fire sprinkler system.

According to another aspect of the present invention there is provided an adjustable sprinkler tee connector for connecting a sprinkler to a fire system water supply line provided in the roof space of a domestic dwelling or other building, the connector comprising:

a tee piece for connecting the sprinkler to the fire system water supply line; and,

an interchangeable extension piece adapted to connect the sprinkler to the tee piece whereby , in use, the sprinkler can be mounted flush in the ceiling of the building by using an appropriate length extension piece.

Preferably a vertical portion of the tee piece is provided with an external thread on which a lock nut is received for locking the tee piece in an aperture of a support bracket.

According to a further aspect of the present invention there is provided a sprinkler mounting system for mounting a plurality of fire sprinklers in the ceiling of a domestic dwelling or other building, the sprinkler mounting system comprising:

an elongate support bracket, adapted to be fastened to the ceiling joists in the ceiling of the building for supporting a fire system water supply pipe therein,

said support bracket being formed with a plurality of apertures at spaced locations for receiving a sprinkler connector tee piece therein; and,

a plurality of pipe clips, adapted to clip onto the support bracket, for retaining the fire system water supply pipe in the support bracket.

Preferably the support bracket is channel-shaped, so that the side walls of the channel-shaped support bracket prevent the fire system water supply pipe from being displaced laterally in a horizontal direction when a surge of water is suddenly released through the pipe.

According to a still further aspect of the present invention there is provided an anti-tamper stop tap security system for securing a water supply authority stop tap from being tampered with so as to render ineffective a fire system for a domestic dwelling or other building, the stop tap securing system comprising:

a lockable cover adapted to completely cover at least the water supply authority stop tap adjacent to a water supply authority water meter for the building; and

a key that can be used by water supply authority personnel to access the cover whereby, in use, unauthorised access to the stop tap is inhibited and the likelihood of the fire system for the building being rendered ineffective is minimised.

Buildings other than domestic dwellings in which the fire sprinkler system of the present invention may be employed include offices, centres and commercial buildings that are located in residential areas, light commercial areas or light industrial areas, and which cannot be connected to the high pressure fire department water supply, and therefore must be supplied from the ordinary mains water supply.

The phrase "mains water supply" as used in the specification and claims is intended to include the supply of water provided by a local or government authority, as generally provided in residential or light commercial areas.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Likewise the word "preferably" or variations such as "preferred", will be understood to imply that a stated integer or group of integers is desirable but not essential to the working of the invention.

Brief Description of the Drawings

The nature of the invention will be better understood from the following detailed description of several specific embodiments of the fire sprinkler system and associated components, given by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic diagram of a domestic dwelling showing one embodiment of a fire sprinkler system in accordance with the present invention;

Figure 2 is a partial section view of a first embodiment of a sprinkler priority valve that may be employed in a fire sprinkler system according to the invention;

Figure 3 illustrates a second embodiment of a sprinkler priority valve that may be employed in a fire sprinkler system according to the invention, shown in situ;

Figure 4 illustrates a variation of location of the sprinkler priority valve of Figure 3;

Figures 5 (a), (b) and (c) illustrate a preferred embodiment of a sprinkler mounting system and sprinkler connector employed in the fire sprinkler system of the present invention;

Figures 6 (a), (b) and (c) illustrate a possible embodiment of a control cabinet for the fire sprinkler system of the present invention;

Figure 7 is an exploded section view through a sprinkler connector similar to that illustrated in Figure 5;

Figure 8 illustrates a third embodiment of a sprinkler priority valve that may be employed in a fire sprinkler system according to the invention;

Figure 9 illustrates the sprinkler priority valve of Figure 8 in the sprinkler system operating position;

Figure 10 is a section view through a preferred embodiment of a stopcock that may be employed in the fire sprinkler system of the present invention;

Figure 11 is an exploded view of the stopcock illustrated in Figure 10; and

Figure 12 illustrates the stopcock of Figure 10 located in situ.

Detailed Description of Preferred Embodiments

A preferred embodiment of the fire sprinkler system 10 according to the invention, as shown in Figure 1 of the drawings, comprises a plurality of sprinklers 12 adapted to be mounted in the ceiling of a building 14, in this case a domestic dwelling, shown in plan view. The sprinklers 12 are of conventional design and are typically activated when the temperature in a room below exceeds a predetermined maximum. The sprinklers 12 are preferably all connected to a closed loop 16 of a fire system water supply provided in the roof space of the domestic dwelling 14. The closed loop 16 is supplied with water by a fire system water supply line 18, and remains fully charged with pressurised water at all times. Hence if any one of the sprinklers

12 is activated water is immediately available at the required pressure to be sprayed over an area with a defined radius in the room below.

The fire system water supply line 18 is completely independent from a domestic water supply line 20 for supplying water to domestic appliances, such as a washing machine, dishwasher and hot water system, as well as internal taps, showers and toilets. The fire system water supply line 18 runs parallel to the domestic water supply line 20 to the front of the property to a

point near where the water supply authority water meter 22 connects the domestic water supply line 20 to a mains water supply 24. A sprinkler priority valve 26, (see Figures 2 to 4) adapted to be mounted in close proximity to the water supply authority water meter 22, is designed to divert the bulk of the water, in use, from the mains water supply 24 to the fire system water supply line 18 in the event that a sprinkler 12 is activated. In this manner, sufficient water is available at an adequate volume and pressure to feed the sprinkler system 10 should one of the sprinklers 12 be activated.

A wall-mounted control cabinet 28 (see also Figure 6) may be provided in the domestic dwelling for housing an electronic control module and/or a stop tap for the fire system water supply line 18. Electrical cables 30 operatively connect the control module to electrically operated components of the fire sprinkler system 10.

One of the main problems with domestic fire sprinkler systems is the availability of enough water at a specific pressure to feed one or more sprinklers 12 for a sustained period at a sufficient flow rate. Any water drawn off from the cold water supply to a house has traditionally been a minimum of one meter from the water meter 22 (this is a requirement of the water supply authorities). This requirement necessitates draw off after the water meter 22, which by virtue of its operation restricts the flow of available water by as much as 15%. Most house water supply connections are 20mm diameter pipe further restricting the flow rate of available water. In view of diminishing water reserves available for domestic consumption, new legislation is proposed to install limiting valves restricting the pressure to 500KPa in the domestic water supply line 20. It is also proposed to install 20mm dual non-return valves after the water meter 22, which will further restrict the flow rate of water. All of these requirements will significantly reduce the flow rate of water available for supplying a fire sprinkler system.

The present invention overcomes these problems by drawing off the water supply to the fire system water supply line 18 at a point in close proximity to the water supply authority water meter 22, which is typically near the boundary of the property and close to the mains water supply. Preferably, the

water supply to the fire system water supply line 18 is drawn off at a point immediately adjacent to the water meter 22 (see Figures 3 and 4). The provision of the sprinkler priority valve 26, mounted in close proximity to the water supply authority water meter 22, ensures that the bulk of the water is diverted, in use, from the mains water supply 24 to the fire system water supply line 18. Preferably, all the water usage in the house such as a dishwater, washing machine, garden reticulation, pool cleaning/filling, hot water supply, etc is shut off as soon as the fire sprinkler system is activated.

Figure 2 illustrates a simple mechanical embodiment 36 of a sprinkler priority valve 26 that may be employed in the fire sprinkler system of the present invention. The sprinkler priority valve 36 comprises a diverter chamber 38 having a water inlet 40 for receiving water from the mains water supply, a first outlet 42 for directing water to the fire system water supply line, and a second outlet 44 for directing water to a domestic water supply line. In the diverter chamber 38 there is provided a diverter wall element 46 which extends upwardly into the chamber in a smooth curve for directing the flow of water from the inlet 40 over the mouth of the second outlet 44 towards the first outlet 42. A curved copper pipe 48 is joined to the second outlet 44 and extends to a dual check valve 50, which is in turn connected to the fire system water supply line 18 (not shown in Figure 2). Dual check valve 50 prevents the back flow of water from the fire sprinkler system back into the domestic water supply. This is important as the water in the fire sprinkler system may be sitting in the fire system water supply line 18, and in the closed loop 16 in the roof space of the house, for long periods of time, and is a potential breeding ground for micro-organisms; it therefore must not be allowed to contaminate the domestic water supply.

In the event that a sprinkler is activated the diverter chamber 38 diverts the bulk of the water from the water inlet 40 to the first outlet 42. In fact the diverter wall element 46 is preferably designed to create a venturi effect in the diverter chamber 38, so that any water in the second outlet 44 is also sucked into the first outlet 42. In this way, the maximum volume of available water is diverted to the fire system water supply line 18 to be available for feeding the sprinklers 12. One advantage of the mechanical sprinkler priority valve 36 is

that it is entirely passive in operation and does not require any electrical or mechanical actuators. During normal domestic water usage, since the fire system water supply line 18 and the closed loop 16 is fully charged with water, all the water from inlet 40 flows around the diverter wall element 46 through the second outlet 44 to the domestic water supply line. During normal domestic water usage water cannot flow through the first outlet 42 and curved pipe 48 because it is already filled with water, and the water in the fire system supply line 18 cannot flow back into the priority valve 36 because of the check valve 50.

In a more advanced system, the simple mechanical priority valve may be replaced with an electromechanical sprinkler priority valve 56, such as that illustrated in Figures 3 and 4. The sprinkler priority valve 56 comprises a diverter chamber (not visible) having a water inlet 58 for receiving water from the mains water supply, a first outlet 60 for directing water to the fire system water supply line, and a second outlet 62 for directing water to a domestic water supply line. It also includes a solenoid activated shutoff valve 64 for closing the second outlet 62 in the event that a sprinkler is activated, so that bulk of the water from the water inlet 58 is diverted to the first outlet 60. The solenoid activated shutoff valve 64 is under the control of the control module in the control cabinet 28 via the electrical cable 30.

In this embodiment, the fire sprinkler system for a domestic dwelling also comprises a non-return valve 66 with built-in flow sensor for detecting the flow of water through the valve and generating a sensing signal in response to the detection. In use, when a sprinkler in the system is activated by the presence of excessive heat in a particular room in the domestic dwelling 14, the flow sensor in the non-return valve 66 sends a sensing signal to the control module in the control cabinet 28 to indicate the flow of water through the fire system water supply line 18. The control module then immediately activates the solenoid activated shutoff valve 64 to shutoff the supply of water to the main house water supply, so that all the water from the mains water supply is available to the fire sprinkler system.

With fire systems it is always important that the supply of water cannot be interrupted inadvertently or through vandalism. A potential weak point in the domestic fire system 10 is the location of the connection to the mains water supply at the boundary of the house property (typically alongside the pedestrian pathway) where it is easily accessed by members of the public. In order to substantially eliminate the possibility of vandalism an anti-tamper stop tap security system 68 is provided for securing the water supply authority stop tap 70 from being tampered with. The stop tap security system 68 comprises a lockable cover 72 adapted to completely cover at least the water supply authority stop tap 70 adjacent to the water meter 22 for the domestic dwelling. The lockable cover 70 is typically made from metal and in this embodiment is sufficiently large to cover both the stop tap 70 and the sprinkler priority valve 56. A special key (not shown), which can be used by water supply authority personnel, is provided to access the cover 72 whereby, in use, unauthorised access to the stop tap 70 is inhibited and the likelihood of vandalism resulting in the fire system for the domestic dwelling being rendered ineffective is minimised.

The system illustrated in Figure 4 is similar to that of Figure 3, except that the sprinkler priority valve 56 is in a different position. In the system of Figure 3 the priority valve 56 is on the street side of the water meter 22 and hence any water drawn from the mains supply for the fire system need not be paid for by the owner of the domestic dwelling. However some water authorities may prefer that the water drawn from the mains supply for the fire system should be paid for by the owner, in which case the sprinkler priority valve 56 must be moved to the house side of the water meter 22 as shown in Figure 4. In this case the lockable cover 70 of the anti-tamper stop tap security system 68 may be enlarged to cover the water meter 22 as well, or alternatively it may be reduced in size to cover the stop tap 70 only, as illustrated in Figure 4. In other respects the system of Figure 4 is similar to that of Figure 3 and hence the like parts have been identified with the same reference numerals and will not be described again.

With any fire sprinkler system a great deal of attention is given to the pipe fixing/clamping for the fire system supply lines and the fixing of the sprinkler

heads so as to hold them securely in place and directed at a potential fire in the event that sprinklers are activated. If the pipes and sprinkler heads are not securely fixed in position, they may well be displaced due to the reaction forces generated when high pressure water is suddenly released from one or more of the sprinklers. For this reason a sprinkler mounting system 80 is preferably provided for securely mounting a plurality of fire sprinklers 12 in the ceiling of a domestic dwelling 14. The sprinkler mounting system 80 illustrated in Figures 5 (a), (b) and (c) comprises an elongate support bracket 82, adapted to be fastened to the ceiling joists 84 in the ceiling of the domestic dwelling 14 for supporting the fire system water supply pipe 18 therein.

The support bracket 82 of this embodiment is made from pressed steel and is channel-shaped, as can be seen most clearly in Figure 5 (c). It is formed with a plurality of apertures 86 therein at spaced locations, for receiving a sprinkler connector tee piece 94 therein. The channel-shaped support bracket 82 preferably also has a plurality of fixing holes 88 provided therein at spaced intervals for fixing the support bracket 82 to the ceiling joists 84 by suitable fasteners such as nails, staples or screws.

The sprinkler mounting system 80 further comprises a plurality of pipe clips 90, adapted to clip onto the support bracket 82, for retaining the fire system water supply line 18 in the support bracket. The pipe clips 90 clip onto the sides of the channel-shaped support bracket 82 and prevent the fire system water supply pipe 18 from lifting vertically out of the bracket. The side walls of the channel-shaped support bracket 82 prevent the fire system water supply pipe 18 from being displaced laterally in a horizontal direction when a surge of water is suddenly released through the pipe. The manner in which the sprinkler heads 12 are fixed to the support bracket 82 is also carefully designed to suit the domestic environment and to facilitate easy installation.

Each sprinkler 12 is preferably provided with an adjustable sprinkler tee connector 92 for connecting the sprinkler to the closed loop 16 of the fire system water supply line 18 provided in the roof space of the domestic dwelling 14. The connector comprises a tee piece 94 for connecting the sprinkler 12 to the fire system water supply line 18. As can be seen most

clearly in Figure 7, the tee piece 94 has external threads 95 at each end of the horizontal portion of the tee, for receiving threaded connectors 96 for securely connecting each end of the tee piece 94 to the supply pipe 18. The vertical portion of the tee is also provided with an external thread 97 on which a lock nut 98 is received for locking the tee piece 94 in one of the apertures 86 of the support bracket 82. It is also provided with an annular lip 99, which abuts the perimeter of the aperture 86, in the support bracket 82, behind the lock nut 98.

Preferably the sprinkler tee connector 12 is provided with an interchangeable extension piece 100 adapted to connect the sprinkler 12 to the tee piece 94.

The extension piece 100 has an internal thread at a top end thereof adapted to screw onto the external thread 97 of the vertical portion of the tee, and an internal thread at the other end adapted to receive a standard sprinkler head

12 therein. The extension piece 100 is preferably provided in a variety of lengths (100a and 100b) designed to bridge the gap between the support bracket 82 fastened to the ceiling joists 84 and the actual ceiling 102. In this manner the sprinkler 12 can be mounted flush in the ceiling 102 of the domestic dwelling 14 by using the appropriate length extension piece 100, as shown in Figures 5 (a) and (c), depending on the height of the ceiling joists 84.

Figure 6 illustrates a possible embodiment of the control cabinet 28, which is typically housed inside the domestic dwelling 14. The control cabinet 28 may house the electronic control module 110 as well a back-up battery 112. Optionally the cabinet 28 may also house the stop tap for the fire system water supply line 18 and other plumbing components of the fire sprinkler system. The control module 110 may be programmed so that when a sprinkler is activated a fire alarm is also activated, as well as a red strobe light on the outside of the domestic dwelling, and any other security and alarm features that may optionally be included in the fire system. For example, the control module 110 may also be programmed to automatically place a call to the local fire brigade service and to the mobile phone of the owner of the domestic dwelling. Preferably the fire system also includes a plurality of smoke detectors (not shown) operatively connected to the control module

110, which may be designed to trigger the alarm a predetermined time period before a sprinkler is activated.

Figures 8 and 9 illustrate a third embodiment of a sprinkler priority valve 116 that may be employed in the fire sprinkler system of the present invention. The sprinkler priority valve 116 is adapted to be mounted in close proximity to a water supply authority water meter, in a similar position to the valve 56 illustrated in Figures 3 and 4, for diverting the bulk of the water from a mains water supply to the fire system water supply line in the event that a sprinkler is activated. In this embodiment the sprinkler priority valve 116 comprises a diverter chamber having a water inlet 122 meter for receiving water from the mains water supply, a first outlet 120 for directing water to the domestic system water supply line, and a second outlet 118 for directing water to a fire system water supply line. The diverter chamber further comprises a slidable piston 124 which is movable between a first position, as shown in Figure 9, in which the first outlet 1 18 is closed and a second position, as shown in Figure 8, in which the first outlet 118 is open. The piston 124 is formed with two portions of different internal diameter, a first portion 126a of reduced diameter and a second portion 126b of increased diameter. The first portion 126a has an internal check valve 130 which is normally held in the closed position by a spring 131 , preventing the flow of water through the piston 124 from the second portion 126b to the first portion 126a to outlet 118. An aperture 128 is provided in the side wall of the second portion 126b of the piston 124, which is adapted to align with the first outlet 120 in the second position of the piston, as shown in Figure 9.

In use, the sprinkler priority valve 116 operates by virtue of a pressure differential that is created within the diverter chamber when a sprinkler is activated, that causes the piston 124 to slide from the first position (first outlet 118 normally closed) to the second position (first outlet 1 18 open). When a sprinkler 12 is activated in the event of a fire, a pressure drop on the side of the diverter chamber near the first outlet 118, caused by the activation of the fire sprinkler, allows the piston 124 to compress spring 129 and move to that end of the diverter chamber. The movement of position 124 shuts off the supply of water to outlet 120. The water pressure builds up in the second

portion 126b until spring 131 can no longer hold back check valve 130. Check valve 130 then opens as shown in Figure 8 and the water flows through the second portion 126b and first portion 126a of the piston 124 to the first outlet 118. In this manner sprinkler priority valve 116 ensures that all the water from the mains water supply is made available to the fire sprinkler system.

If the fire sprinkler system is to be installed during construction of the building, it may be desirable to isolate the system from the mains water supply so as to prevent contamination of water in the fire system supply line with dust or other particles. Such contaminants can block the sprinkler heads and seriously compromise the efficacy of the system. Figures 10 to 12 illustrate a preferred embodiment of a stop cock 130 for isolating the fire sprinkler system from the mains water supply. Stop cock 130 comprises a first inlet 132 for connection to a mains water supply 24 (see Figure 12). A first "outlet" 134 for connection to the fire system water supply line 18 is provided in line with the first inlet 132. Water cannot in fact pass through "outlet" 134 as there is a wall 136 blocking this outlet, as shown in Figure 10. A bleed outlet 138 is provided on one side of the stop cock 130, with a bleed valve 140 provided therein for opening and closing the bleed outlet 138. When valve 140 is open water can flow from the mains water supply through the first inlet and out through the bleed outlet to bleed line 142.

In use, during construction of the building, the sprinkler priority valve is not installed until later. In its place the stop cock 130 is installed between the mains water supply 24 and the fire system water supply line 18, as shown in Figure 12. The stop cock 130 thus ensures that no dust or other contaminants can enter the fire system water supply line 18 since the wall 136 in the stop cock 130 completely blocks the flow of water into the water supply line 18. When construction is completed and it is time to commission the fire sprinkler system, the mains water supply 24 can be flushed of dust particles by opening bleed valve 140. Water carrying any dust particles or other contaminants can be flushed out through the bleed line 142. The stop cock 130 is then removed by cutting the water supply line 18 and mains supply 24 at the lines A-A'. The sprinkler priority valve according to the invention is then installed in its place.

Now that preferred embodiments of the fire sprinkler system for a domestic building and associated components of the system have been described in detail, it will be apparent that it provides a number of advantages, including the following:

(i) The system will ensure that an adequate supply of water at the required pressure is always available to the sprinklers for a sustained period and at a sufficient rate.

(ii) The system satisfies water authority requirements and is suitably isolated from the domestic water supply so as to prevent back flow contamination.

(iii) The sprinkler mounting system provides a secure means of mounting the sprinklers in the ceiling of the domestic building.

(iv) The anti-tamper stop tap security system inhibits unauthorised or inadvertent disconnection of the fire system from the mains water supply.

(v) The system is relatively inexpensive and easy to install; the costs being comparable to a domestic air-conditioning system.

It will be readily apparent to persons skilled in the relevant arts that various modifications and improvements may be made to the foregoing embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention. For example, the sprinkler priority valve may incorporate a combination of the mechanical and electromechanical elements of the described embodiments. Therefore, it will be appreciated that the scope of the invention is not limited to the specific embodiments described and is to be determined from the appended claims.