AU2008253591A1

AU2008253591A1 - Fittings for water storage tank

Info

Publication number: AU2008253591A1
Application number: AU2008253591A
Authority: AU
Inventors: Terry Mcdermott; Luciano Papi; Neil Wallace
Original assignee: BlueScope Steel Ltd
Current assignee: BlueScope Steel Ltd
Priority date: 2007-05-18
Filing date: 2008-05-19
Publication date: 2008-11-27
Also published as: CN101743363A; MX2009012457A; US20100147845A1; BRPI0811729A2; TW200902803A; CA2687470A1; WO2008141374A1

Description

WO 2008/141374 PCT/AU2008/000700 FITTINGS FOR WATER STORAGE TANK FIELD OF THE INVENTION 5 The present invention relates to fittings for a water storage tank for use, by way of example, for catchment and storage of water in domestic and rural settings. 10 The primary purpose of the fittings of the present invention is to transfer water into and out of the water storage tank. 15 The term "water" as used herein is understood in the broadest sense to include stormwater, rainwater, sewage, effluent and combinations thereof unless otherwise specified. 20 BACKGROUND OF THE INVENTIION Tanks are commonly used for collecting rainwater runoff from roofs in domestic and rural settings via downpipes for storage of the water to supplement mains 25 water supply and other freshwater sources. In many localities, it is a requirement for new dwellings under construction or extensions to existing dwellings to include a water storage tank. 30 Conventionally, such water storage tanks have a rounded profile and are bulky, the diameter of tanks being largely dependent on the water holding capacity. Such tanks are sealed to provide an interior volume for the reception and storage of water, and include steel tanks 35 and tanks fabricated from plastics materials. The tanks have fittings in the form of: inlets for passage of water into the tanks; outlets for passage of water from the WO 2008/141374 PCT/AU2008/000700 -2 tanks; and overflow outlets. International application PCT/AU2007/000479 entitled "Water Storage Tank" lodged on 27 April 2007 in 5 the name of the applicant and published as International publication WO 2007/124530 describes and claims an invention of another type of water storage tank that comprises an outer shell that defines an interior of the tank and at least one water catchment bag located in the 10 tank interior. By using the bag or bags to collect and store water, the outer shell of the tank need not be sealed for retention of water. Moreover, the bag or bags may be arranged in a standing, self-supporting position within the outer shell of the tank to thereby provide 15 their own structural support independently of the shell when the bag or bags are filled with water in use. This allows the outer shell of the tank to be relatively thin walled with a concomitant saving in the cost of materials used for its fabrication. Such tanks also have fittings 20 in the form of: inlets for passage of water into the tanks; outlets for passage of water from the tanks; and overflow outlets. The disclosure in the above-mentioned 25 International application is incorporated herein by cross reference. SUMMARY OF THE INVENTION 30 The fittings of the present invention are purpose designed for water storage tanks of the type described and claimed in the above-mentioned International application that have at least one internal water catchment bag, preferably a self-supporting bag, located in the interior 35 of an outer shell. The purpose-built structure of the fittings of WO 2008/141374 PCT/AU2008/000700 -3 the present invention distinguishes the fittings from fittings for conventional water tanks. The fittings of the present invention comprise 5 three separate sub-systems for the above type of water storage tank, namely: (a) an inlet sub-system for allowing the passage of water into the tank; 10 (b) an outlet sub-system for allowing the passage of water from the tank; and (c) an overflow outlet sub-system for allowing 15 the passage of water from the tank. The present invention relates to the above mentioned fittings separately. 20 The present invention also relates to a water storage tank that comprises an outer shell that defines an interior of the tank, at least one water catchment bag located in the tank interior, and any one or more than one of the above-mentioned fittings connected as required to 25 the outer shell and the bag or bags. Preferably the bag is a self-supporting bag formed from a polymeric material. 30 Preferably the tank shell has side walls and end walls and the bag is fabricated from flexible sheet material that is impervious to passage of water or other liquid and the bag has a structure such that when the bag is installed within the tank shell and filled with liquid, 35 the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.

WO 2008/141374 PCT/AU2008/000700 -4 Preferably the tank shell is elongated with parallel side walls and curved end walls and a lid, and with the length of the side walls being greater than the 5 spacing between the side walls. Preferably the bag comprises a series of interconnected tubular cells extending from a base of the tank to the top of the side walls and end walls, the 10 configuration of the bag in its uninstalled state being such that when the bag is installed within the tank shell and is filled with water or other liquid, the cells at the respective ends of the bag engage the adjacent end wall of the tank shell and are deformed into a non-cylindrical 15 shape, and the or each cell intermediate the end cells is deformed into an elongate shape transversely of the side walls of the tank, the or each intermediate cell having part-cylindrical end walls which are positioned in relation to the side walls of the tank shell when in the 20 installed state whereby the side walls of the tank shell are not subject to substantial, if any, water or other liquid pressure tending to distort the side walls. Preferably the lid of the tank shell is a 25 removable lid having an opening therein and the inlet sub system is connected to the bag or to one of the bags and is coupled to the lid and arranged to extend through the opening in the lid. 30 Preferably the inlet sub-system has one of its components welded or otherwise connected to the bag Preferably the overflow outlet sub-system has one of its components welded or otherwise connected to the 35 bag. Preferably the outer shell includes at least one WO 2008/141374 PCT/AU2008/000700 -5 opening in a lower section of the shell and the outlet sub-system is connected to the bag or to one of the bags and is coupled to the shell and arranged to extend through the opening in the shell. 5 Preferably the outlet sub-system has one of its components welded or otherwise connected to the bag. Preferably the outer shell includes at least one 10 opening in an upper section of the shell and the overflow sub-system is connected to the bag or to one of the bags and is coupled to the shell and arranged to extend through the opening in the shell. 15 Preferably the overflow sub-system has one of its components welded or otherwise connected to the bag. The water storage tank fittings of the present invention are distinguished from conventional fittings by 20 virtue of any one or more than one of the functions of: (a) locating a water catchment bag or bags relative to an outer shell of a water storage tank; 25 (b) restraining the bag or bags from moving within the outer shell; and (c) preventing leaks in the bag/shell interfaces; and 30 while ensuring the transfer of water into and out of the tank. Furthermore, each of the fittings of the present 35 invention has features over and above conventional fittings as will become more apparent from the following description.

WO 2008/141374 PCT/AU2008/000700 -6 A. The inlet sub-system. The inlet sub-system is adapted to transfer water 5 from outside a water storage tank into the tank. For example, the water may be rainwater harvested from roofs of houses or sheds via downpipes. The inlet sub-system comprises a plurality of 10 components. Typically, the inlet sub-system comprises the following five individual components that fit together to form the assembled sub-system, as described below: 15 (a) A weld ring that can be positioned inside an outer shell of a water storage tank and affixed to a top of a water catchment bag located in the outer shell by fusing the weld ring, typically via a heat or an 20 ultrasonic or another suitable fusion technique, to the bag. Typically, the weld ring is made from a polyethylene and is welded to the bag of the same or similar material specification. Typically the weld ring comprises an annular flange that has a flat surface for welding to the 25 bag and a vertical shank with spaced-apart bayonet fixings that are adapted to connect the weld-ring to a mating part of a retaining ring described hereinafter that is positioned outside the tank shell. Fusing the weld ring to the bag assists in the prevention of water leakage and 30 positively assists in restraining the bag from collapsing when empty or partially full. (b) A retaining ring that has complimentary bayonet fixings to those of the weld ring to allow the 35 retaining ring and the weld ring to be quickly and efficiently coupled together. The retaining ring has an annular flange that contacts an outside surface of a top WO 2008/141374 PCT/AU2008/000700 -7 lid of the tank and a cylindrical sleeve that extends from the flange through an opening in the tank lid. The cylindrical sleeve terminates in an inwardly and upwardly extending lip that defines a channel for receiving a light 5 guard of the inlet fitting, as described hereinafter. The bayonet fittings are provided in a transition between the flange and the sleeve. The arrangement is such that engagement of the bayonet fittings of the weld ring and the retaining ring clamps the tank lid between the weld 10 ring and the retaining ring. The retaining ring also has holes that allow further fixings (screws or canoe clips or Christmas tree fixings or scrivets) to engage the tank lid to ensure a semi-permanent engagement of the weld ring, tank lid, and retaining ring. The retaining ring is 15 typically made from an ultraviolet-stabilised polypropylene. (c) An inlet/strainer that can be connected to the retaining ring via mating bayonet quick release 20 fixings on the inlet/strainer and the retaining ring. The inlet/strainer has a suitable mesh, typically made from stainless steel wire, moulded into the component to comply with the current and intended regulations for the prevention of vermin and mosquitoes entering the tank and 25 vector proofing as well as providing a filtration system for preventing leaves and other debris from entering the tank. When coupled to the retaining ring, the mesh extends across the opening in the tank lid. The inlet/strainer comprises a tamperproof/childproof function 30 that is intended to prevent decoupling from the retaining ring by a child but does allow fast decoupling from the water storage tank by an adult for maintenance purposes, for example, to remove debris from the filter mesh. Typically, the body of the inlet/strainer is constructed 35 from an ultraviolet-stabilised polypropylene. (d) A generally circular light guard that is WO 2008/141374 PCT/AU2008/000700 -8 separate to the retaining ring but is formed to be housed within and mounted to the retaining ring and is retained in position by the inlet/strainer being positioned above the light guard. The light guard comprises an outer 5 peripheral flange that can be positioned to extend into the above-described channel in the retaining ring. The light guard is formed to extend across the opening in the tank lid and to allow passage of water but restricts the passage of ultraviolet light into the tank (i.e. inside 10 the bag or bags of the tank) This component is typically made from an ultraviolet-stabilised polypropylene. (e) A compression gasket that prevents leakage of water from inside the bag or bags of the tank through 15 the inlet system connections to the cavity between the outside of the bag and the inside of the outer shell under the conditions of backwash. This typically is constructed using moulded Seblex (Registered Trade Mark) polyolefin elastomer. 20 The entire inlet sub-system design facilitates the assembly of the bag or bags within the outer shell to the outer shell with innovative orientation of components, quick connect/locking features of mating components and 25 multifunctional features such as allowing the passage of water but restricting the ingress of ultraviolet light and also providing for the optional fitment of a proprietary off the self filter bag. 30 Typically, there are two inlets per tank, preferably located at each end of the tank and preferably connected to the bags at the ends of the tank - in a tank comprising a plurality of bags - or to the end compartments in a single bag configuration in a tank. 35 Additionally, the inlet sub-system is so designed that, by the simple elimination of the above-described WO 2008/141374 PCT/AU2008/000700 -9 weld ring and the compression gasket, the remaining components can be utilised as an inlet sub-system on a conventional tank without modification to the remaining components or assembly process or procedure. 5 Additionally, the inlet sub-system is so designed that it can be used in combination with a submerged pump system. 10 B. The outlet sub-system. The outlet sub-system typically transfers water from inside the tank to outside the tank for the purpose of using the stored water or other liquid contents in the 15 tank. The outlet sub-system comprises a plurality of components. 20 Typically, the outlet sub-system comprises five individual components that fit together to form the assembled sub-system, as described below: (a) A main outlet body having a weld ring 25 typically constructed from a polyethylene that is over moulded to a spigot or shaft that is typically a cast and/or machined zinc alloy. The spigot/shaft can also be manufactured from other metallic materials or other fire resistant non-metallic materials. The spigot/shaft 30 defines a support for the weld ring. The polyethylene weld ring is fusion-welded to the bag, typically of the same material specification as the weld ring. When positioned in relation to a tank, the metallic spigot protrudes through the tank shell and is threaded to allow 35 the attachment of a plug or tap or other plumbing fittings that allows water flow from within the tank to outside the tank to be controlled or directed. The over-moulded zinc WO 2008/141374 PCT/AU2008/000700 - 10 alloy spigot/shaft body also has, as part of its design, a mechanical key engagement to assist in the prevention of the relative rotational movement of weld ring (which has a mating mechanical key engagement with the shaft) to 5 spigot/shaft whilst under a torsional load. The weld ring assists in the prevention of water leaks from the bag to the outer shell and in combination with other components in the outlet sub-system prevents the bag from twisting when the fittings are under torque by the actions of 10 plumbers fitting external apparatus onto the outlet spigot/shaft. The weld ring has a "dog" clutch feature that comprises a plurality of dogs that can engage with a "dog" clutch feature of an internal adaptor plate described hereinafter to prevent rotation when either the 15 fitting is tightened from the external protruding spigot/shaft or plumbing fittings are attached to the externally projecting spigot/shaft of the outlet. (b) An internal adaptor plate that is adapted 20 to orientate the outlet body within the tank shell and is formed to contact the inside of the tank shell. Specifically, in situations in which the tank shell is made from profiled (such as corrugated) panels, the internal adaptor plate has a mating wave-type profile that 25 conforms to the internal corrugations of the tank shell. This feature makes it possible to self orientate the vertical location of the internal adaptor plate to the tank shell via the wave-type profile (corrugations) of the tank shell inner surface. The internal adapter plate also 30 has a mating "dog" clutch feature, i.e. a series of openings to receive and engage the dogs of the mating weld ring. Typically, this component is manufactured from a polypropylene. The inner surface of the internal adaptor plate, i.e. the surface that faces inwardly when the 35 internal adaptor plate is positioned in a tank shell, also transitions gently to the inner surface of the tank inner shell such that the bag flows over the face of the WO 2008/141374 PCT/AU2008/000700 - 11 component not to induce stress into the bag under hydrostatic load conditions. (c) An external adaptor plate is formed with a 5 profile, such as a wave-type profile in the case of a corrugated tank shell, to mate to the outer profile of the tank shell and to provide a transition from the profile to a flat bearing surface that enables a lock nut described hereinafter to engage against and tighten the entire 10 outlet assembly. In situations in which the tank shell is made from profiled (such as corrugated) panels, the external adaptor plate is formed so that the profile in plan view is such that it is a common component that suits all sweeps of the tank range. This is further facilitated 15 by the next described component, i.e. a compressible gasket, which is formed to assist in compensating for differences in the fixed sweep of the external adaptor plate and the various sweeps of the water tank range. Typically, the external adaptor is manufactured from a 20 zinc alloy for the purposes of fire resistance. It can also be manufactured from other metallic or non-metallic fire resistant materials. (d) A lock nut, which is typically a left 25 handed thread matching that of the shaft body, that is adapted to engage the spigot/shaft of the main outlet body. The engagement makes it possible to force the external and the internal adaptor plates against outer and inner surfaces respectively of the tank shell. For the 30 same reasons as the spigot/shaft and the external adaptor, typically this component is manufactured from a zinc alloy but is not restricted to such a material choice where other metallic or non-metallic materials with fire resistance characteristics could also be suitable for this 35 application. (e) A compressible gasket is used in WO 2008/141374 PCT/AU2008/000700 - 12 conjunction with the external adaptor plate to make a smooth transition from a common profile in plan view of the above-mentioned external adaptor plate and the outer surface of the tank shell. Typically, this component is 5 constructed from moulded silicon. Typically, there are two outlet sub-systems, one at each end of the tank down towards the bottom of the tank, preferably connected to each of the end bags in a 10 plurality bag construction or at the end cells of the bag. Additionally, the outlet sub-system is so designed that the components can be utilised as an outlet sub-system on a conventional tank with the simple addition 15 of two compression gaskets, one between the weld ring and internal adaptor and the other between the internal adaptor and the tank shell and with little change to the assembly process or procedure. 20 C. The overflow sub-system The overflow sub-system transfers water (or other liquid as deemed suitable) from inside the water storage tank to the outside of the tank under a full tank capacity 25 situation and is designed to prevent the water from backwashing out of the inlet sub-system. It can be allowed to vent to atmosphere. However, in an urban situation it is more typically plumbed into a storm water system to allow the excess water superfluous to the tank stored 30 volume to escape to the storm water drainage system. The overflow sub-system comprises a plurality of components. 35 Typically the overflow sub-system comprises five individual components that fit together to form the assembled sub-system, as described below: WO 2008/141374 PCT/AU2008/000700 - 13 (a) A weld ring that is fusion welded to the end bag or bags positioned in a tank shell. The material is typically a polyethylene. The weld ring comprises an 5 oval flange that provides a flat weld surface and a sleeve that extends from an inner edge of the flange. The flange also provides a surface on which a compression gasket described hereinafter seals the weld ring to the body of the overflow sub-system described hereinafter. The sleeve 10 is designed to be a female type engagement such that the overflow body male engagement fits inside the spout of the weld ring. (b) An overflow body that has an oval sleeve 15 with outwardly operable snap lock fittings is designed to engage with the sleeve of the weld ring. The dimensions, including the lengths of the sleeves are selected so that the sleeve of the weld ring can extend into the sleeve of the overflow body and the snap lock fittings of the 20 overflow body can engage the flange of the weld ring and etain the two components together. The assembly of the two components together also relies on the compressive characteristics of the compression seal gasket described hereinafter to preload the snap lock fittings. The 25 overflow body has a cross sectional transition from oval to round that provides for the same cross sectional area from inner to outer shape (oval to round) and provides for additional volume retention inside that tank by virtue of the bottom invert of the overflow body being substantially 30 higher on the inside of the tank than the bottom invert of the overflow body on the outside of the tank. It is noted that alternative forms of the overflow body have transitions that mate with other shapes of pipes (stormwater), for example rectangular. When positioned in 35 relation to a tank, the overflow body transitions from inside the tank shell to the outside of the outer shell by passing through the shell surface and has a number, WO 2008/141374 PCT/AU2008/000700 - 14 typically four, screw bosses that engage on the inner surface of the outer shell regardless of the sweep of the tank. This is achieved by a combination of sweep detail in the plan view of the overflow body and the location and 5 dimensional depth of the screw bosses that allow the positive location of the bosses on the inner surface of the tank shell at all times independent of the sweep of the tank. The overflow is typically constructed from an ultraviolet-stabilised poly vinyl chloride (PVC), which 10 allows it to be connected to standard external plumbing accessories by solvent welding. The inner surface of the overflow body also transitions gently to the inner surface of the tank inner shell such that the bag flows over the face of the component not to induce stress into the bag 15 under hydrostatic load conditions. (c) An inner compression gasket that seals the weld ring flange to the back end (inner side) of the overflow body to prevent water ingress from the bag to the 20 inner tank shell as well as providing preload for the snap lock fasteners on the overflow body to the weld ring sleeve. Typically, this component is constructed from a moulded compound but is not restricted to this material and as with all gaskets in this document can be 25 constructed from any material whose mechanical and short and long-term durability performance characteristics meet the requirements of the application. (d) An outer compression gasket is used in 30 conjunction with the external retaining ring to make a smooth transition from a common profile in plan view of the following mentioned external retaining ring and the 4 different sweeps of the outer surface of the tank shell. Typically, this component is constructed from moulded 35 Seblex but is not restricted to this material and as with all gaskets in this document can be constructed from any material whose mechanical and short and long-term WO 2008/141374 PCT/AU2008/000700 - 15 durability performance characteristics meet the requirements of the application. (e) An external retaining ring having an inner 5 surface that has a wave-type profile that mates to the outer profile of the corrugated tank shell and provides a transition from the corrugation profile to flat outer or outboard surface. An important feature of the external retaining ring is that the profile in plan view is such 10 that it is a common component that suits all 4 sweeps of the tank range. This is further facilitated by the above component, a compressible gasket, to assist in compensating for the difference in the fixed sweep of the external retaining ring inner surface and the various 15 sweeps of the water tank range. Typically, the external retaining ring is manufactured from ultraviolet stabilised polypropylene. It can also be manufactured from other non-metallic or metallic materials suitable for this application. The external retaining ring is assembled to 20 the overflow body by a number, typically four, of "high low" screw fixings, typically stainless steel, extending into the corresponding four off-bosses of the overflow body. Other fixings options such as, for example, clips or self tapping screws can substitute for the "high-low" 25 fixings described above. This attachment procedure then holds the overflow sub-assembly rigidly to the tank shell by compression, which in turn locates and restrains the bag at this specific location. Typically, there is one overflow sub-system but not necessarily restricted to one, 30 at the end and the top of the tank preferably connected to the end bag in a tank construction having a plurality of bags or at the end cells of the bag in a multi-compartment single bag construction. 35 Additionally, the overflow sub-system is so designed that, by the simple elimination of the above described weld ring and the internal compression gasket, WO 2008/141374 PCT/AU2008/000700 - 16 the remaining components can be utilised as an overflow sub-system on a conventional tank without modification to the remaining components or assembly process or procedure. Furthermore, these sub-systems can also be utilised on 5 other conventional corrugated tanks of round construction (as distinct from oval tanks of the "Slimline*" range) where the diameters of such tanks suit the sweep of the fittings components. 10 According to the present invention there is also provided each of the components of the above-described inlet sub-system, outlet sub-system, and overflow sub system as separate components. 15 Any discussion of documents, acts, materials, devices, articles or the like which has been included in this specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters 20 form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia or elsewhere before the priority date of this application. 25 Throughout this specification the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other 30 element, integer or step, or group of elements, integers or steps. The features and advantages of the present invention will become further apparent from the following 35 detailed description of preferred embodiments together with the accompanying drawings.

WO 2008/141374 PCT/AU2008/000700 - 17 BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The present invention is described further by way of example with reference to the accompanying drawings, of 5 which: Figure 1 is a perspective view of one embodiment of an assembled inlet sub-system in accordance with the present invention; 10 Figure 2 is a vertical cross section through the assembled inlet sub-system shown in Figure 1; Figure 3 is a perspective view of a weld ring of 15 the assembled inlet sub-system shown in Figure 1; Figure 4 is a vertical cross section through the weld ring shown in Figure 3; 20 Figure 5 is a perspective view of a retaining ring of the assembled inlet sub-system shown in Figure 1; Figure 6 is a vertical cross section through the retaining ring shown in Figure 5; 25 Figure 7 is a perspective view of an inlet/strainer of the assembled inlet sub-system shown in Figure 1; 30 Figure 8 is a vertical cross section through the inlet/strainer shown in Figure 7; Figure 9 is a perspective view of a light guard of the assembled inlet sub-system shown in Figure 1; 35 Figure 10 is a vertical cross section through the light guard shown in Figure 9; WO 2008/141374 PCT/AU2008/000700 - 18 Figure 11 is a perspective view of a gasket of the assembled inlet sub-system shown in Figure 1; 5 Figure 12 is a vertical cross section through the gasket shown in Figure 11; Figures 13 and 14 are perspective views of one embodiment of an assembled outlet sub-system in accordance 10 with the present invention; Figures 15 and 16 are side views of the assembled outlet sub-system shown in Figures 13 and 14; 15 Figure 17 is an end view of the assembled outlet sub-system shown in Figures 13 and 14; Figure 18 is a vertical cross section through the assembled outlet sub-system shown in Figures 13 and 14; 20 Figures 19 and 20 perspective views of a main outlet body of the assembled outlet sub-system shown in Figures 13 to 17; 25 Figures 21 and 22 are side views the main outlet body shown in Figures 19 and 20; Figure 23 is an end view the main outlet body shown in Figures 19 and 20; 30 Figure 24 is a vertical cross section the main outlet body shown in Figures 19 and 20; Figures 25 and 26 are perspective views of an 35 internal adaptor plate of the assembled outlet sub-system shown in Figures 13 to 17; WO 2008/141374 PCT/AU2008/000700 - 19 Figures 27 and 28 are side views of the internal adaptor plate shown in Figures 25 and 26; Figure 29 is an end view of the internal adaptor 5 plate shown in Figures 25 and 26; Figures 30 and 31 are perspective views of the external adaptor plate of the assembled outlet sub-system shown in Figures 13 to 17; 10 Figures 32 and 33 are side views of an external adaptor plate shown in Figures 30 and 31; Figure 34 is an end view of the external adaptor 15 plate shown in Figures 30 and 31; Figure 35 is a perspective view of a gasket of the assembled outlet shown in Figures 13 to 17; 20 Figures 36 and 37 are side views of the gasket shown in Figure 35; Figure 38 is an end view of the gasket shown in Figure 35; 25 Figures 39 and 40 are perspective views of one embodiment of an assembled overflow sub-system in accordance with the present invention; 30 Figures 41 and 42 are side views of the assembled overflow sub-system shown in Figures 39 and 40; Figure 43 is an end view of the assembled overflow sub-system shown in Figures 39 and 40; 35 Figure 44 is a vertical cross section through the assembled overflow sub-system shown in Figures 39 and 40; WO 2008/141374 PCT/AU2008/000700 - 20 Figures 45 and 46 are perspective views of a weld ring of the assembled overflow sub-system shown in Figures 39 to 44; 5 Figures 47 and 48 are side views of the weld ring shown in Figures 45 and 46; Figure 49 is an end view of the weld ring shown 10 in Figures 45 and 46; Figure 50 is a perspective view of an overflow body of the assembled overflow sub-system shown in Figures 39 to 44; 15 Figures 51 and 52 are side views of the the overflow body shown in Figure 50; Figure 53 is an end view of the weld ring shown 20 in Figure 50; Figure 54 is a perspective view of an outer compression gasket of the assembled overflow sub-system shown in Figures 39 to 44; 25 Figures 55 and 56 are side views of the outer compression gasket shown in Figure 54; Figure 57 is an end view of the outer compression 30 gasket shown in Figure 54; Figure 58 is a perspective view of an external locking ring of the assembled overflow sub-system shown in Figures 39 to 44; 35 Figures 59 and 60 are side views of the external locking ring shown in Figure 58; WO 2008/141374 PCT/AU2008/000700 - 21 Figure 61 is an end view of the external locking ring shown in Figure 58; 5 Figure 62 is a perspective view of an inner compression gasket of the assembled overflow sub-system shown in Figures 39 to 44; Figures 63 and 64 are side views of the inner 10 compression gasket shown in Figure 62; and Figure 65 is an end view of the inner compression gasket shown in Figure 62. 15 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The fittings shown in the Figures are adapted to be used as part of a water storage tank of the type described and claimed in the above-mentioned International 20 publication WO 2007/124530, incorporated herein by cross reference. Whilst not shown in the drawings (but as shown in the drawings of the International publication), the water 25 storage tank comprises an outer shell (not shown) that defines an interior of the tank, a series of openings (not shown) in upper and lower sections of the shell to accommodate the fittings, a plurality of self-supporting water catchment bags (not shown) made from a polymeric 30 material located in the tank interior, and a base (not shown) supporting the outer shell and the bags. Typically, the tank shell is elongated with parallel side walls and curved end walls and a removable 35 lid, and with the length of the side walls being greater than the spacing between the side walls.

WO 2008/141374 PCT/AU2008/000700 - 22 Typically, the side walls and the end walls of the outer shell is made from panels that are fabricated from thin-walled (typically 0.6 mm and optionally 0.55 nun or thinner) corrugated steel. The end and side panels 5 overlap and are respectively secured together by fasteners typically in the form of galvanised bolts or solid rivets received in aligned apertures defined in the panels, thereby forming joints. Generally, the outer shell of the tank has a width of from about 400 mm to about 1,500 mm 10 but is not necessarily restricted to this range. The length of the outer shell typically is in a range of from about 1,400 mm to about 3,600 mm in length. The height of the outer shell typically is in a range of from about 1,300 mm to about 2,500 mm. Typically, the lid of the 15 outer shell is fabricated from thin-walled steel. The fittings shown in the Figures comprise an inlet sub-system 3 having the above-described components in the outer shell for passage of water into the bags, an 20 outlet sub-system 47 having the above-described components in the outer shell for passage of water from the bags out of the tank, and an overflow sub-system 77 having the above-described components that is plumbed to a drainage system in an upper region of the tank. 25 Each of the embodiments of the fittings shown in the Figures is now described with reference to the Figures A. The inlet sub-system - Figures 1-12. 30 The inlet sub-system 3 comprises the following five individual components that fit together to form the assembled sub-system shown in Figures 1 and 2, as described below: 35 (a) A weld ring 5 that can be positioned inside an outer shell of a water storage tank and fixed to a top WO 2008/141374 PCT/AU2008/000700 - 23 of a water catchment bag located in the outer shell by fusing the weld ring, typically via a heat or an ultrasonic or another suitable fusion technique, to the bag. The weld ring is made from a polyethylene and is 5 welded to the bag of the same or similar material specification. The weld ring comprises an annular flange 7 that has a flat surface for welding to the bag and a vertical shank 9 with spaced-apart upwardly and inwardly turned bayonet fixings 11 that are adapted to connect the 10 weld ring to a mating part of a retaining ring described hereinafter that is positioned outside the tank shell. (b) A retaining ring 13 that has complimentary bayonet fixings 15 to those of the weld ring 3 to allow 15 the retaining ring 13 and the weld ring 3 to be quickly and efficiently coupled together. The retaining ring 13 has an annular flange 17 that contacts an outside surface of the lid of the tank and a cylindrical sleeve 19 that, when positioned in relation to the tank, extends from the 20 flange 17 through an opening in the tank lid. The cylindrical sleeve 19 terminates in an inwardly and upwardly extending lip 21 that defines a channel 23 for receiving a light guard of the inlet fitting, as described hereinafter. The bayonet fittings 15 are provided in a 25 transition 25 between the flange 17 and the sleeve 19. The arrangement is such that engagement of the bayonet fittings 11, 15 of the weld ring 3 and the retaining ring 13 clamps the tank lid between the weld ring and the retaining ring. The retaining ring 13 also has holes 27 30 that allow further fixings (screws or canoe clips or Christmas tree fixings or scrivets) to engage the tank lid to ensure a semi-permanent engagement of the weld ring, tank lid, and retaining ring. The retaining ring is typically made from an ultraviolet-stabilised 35 polypropylene. (c) An inlet/strainer 29 that can be connected WO 2008/141374 PCT/AU2008/000700 - 24 to the retaining ring 13 via mating bayonet quick release fixings on the inlet/strainer and the retaining ring. The inlet/strainer has a suitable mesh 33, typically made from stainless steel wire, moulded into the component to comply 5 with the current and intended regulations for the prevention of vermin and mosquitoes entering the tank as well as providing a filtration system for preventing leaves and other debris from entering the tank. When coupled to the retaining ring 13, the mesh 33 extends 10 across the opening in the tank lid. Typically, the body of the inlet/strainer is constructed from an ultraviolet stabilised polypropylene. (d) A generally circular light guard 35 that is 15 separate to the retaining ring 13 but is formed to be housed within and mounted to the retaining ring 13 and is retained in position by the inlet/strainer 29 being positioned above the light guard. The light guard 35 comprises an outer peripheral flange 37 that can be 20 positioned to extend into the above-described channel 23 in the retaining ring 13. The light guard 35 is formed to extend across the opening in the tank lid and to allow passage of water but restricts the passage of ultraviolet light into the tank (i.e. inside the bag or bags of the 25 tank) This component is typically made from an ultraviolet-stabilised polypropylene. (e) A compression gasket 41 that prevents leakage of water from inside the bag or bags of the tank 30 through the inlet system connections to the cavity between the outside of the bag and the inside of the outer shell under the conditions of backwash. This typically is constructed using moulded Seblex polyolefin elastomer. 35 B. The outlet sub-system - Figures 13-38. The outlet sub-system 47 comprises five WO 2008/141374 PCT/AU2008/000700 - 25 individual components that fit together to form the assembled sub-system shown in Figures 13-18, as described below: 5 (a) A main outlet body 49 having a weld ring 51 typically constructed from a polyethylene that is over moulded to a spigot or shaft 53. The spigot/shaft 53 defines a support for the weld ring 51. The spigot/shaft 53 typically is a cast and/or machined zinc alloy. The 10 spigot/shaft 53 can also be manufactured from other metallic materials or other fire resistant non-metallic materials. The polyethylene weld ring 51 is fusion-welded to the bag, typically of the same material specification as the weld ring. When positioned in relation to a tank, 15 the metallic spigot 53 protrudes through an opening in the tank shell and is threaded (not shown) to allow the attachment of a plug or tap or other plumbing fittings (not shown) that allows water flow from within the tank to outside the tank to be controlled or directed. The over 20 moulded zinc alloy spigot/shaft 53 also has, as part of its design, a mechanical key engagement to assist in the prevention of relative rotational movement of the weld ring 51 (which has a mating mechanical key engagement with the shaft) and the spigot/shaft 53 whilst under a 25 torsional load. Specifically, the weld ring 51 has a "dog" clutch feature 55 in the form of a plurality of spaced-apart dogs that can engage with a "dog" clutch feature of an internal adaptor plate 57 described hereinafter to prevent rotation when either the fitting is 30 tightened from the external protruding spigot/shaft 53 or plumbing fittings are attached to the externally projecting spigot/shaft 53 of the outlet. (b) An internal adaptor plate 57 that is 35 mounted to the spigot/shaft 53 and orientates the outlet body 49 within the tank shell and is formed to contact the inside surface of the tank shell. Specifically, the WO 2008/141374 PCT/AU2008/000700 - 26 internal adaptor plate 57 has a mating wave-type profile 59 to the internal corrugations of the tank shell. This feature self orientates the vertical location of the internal adaptor plate 57 to the tank shell via the wave 5 type profile (corrugations) of the tank shell inner surface. The internal adapter plate 57 also has a mating "dog" clutch feature, i.e. a series of openings 61 to receive and engage the dogs 55 of the mating weld ring 51 of the outlet body 49. Typically, this component is 10 manufactured from a polypropylene. The inner surface of the adaptor plate 57, i.e. the surface 63 that faces inwardly when the internal adaptor plate 57 is positioned in a tank shell, transitions gently to the inner surface of the tank inner shell such that the bag flows over the 15 face of the component so as not to induce stress into the bag under hydrostatic load conditions. (c) An external adaptor plate 65 is formed with a wave-type profile 67 to mate to the outer profile of the 20 corrugated tank shell and to provide a transition from the corrugation profile to a flat bearing surface that enables a lock nut 69 (Figures 13-18) described hereinafter to engage against and tighten the entire outlet assembly to tank shell. The external adaptor plate 65 is formed so 25 that the profile 67 in plan view is such that it is a common component that suits all sweeps of the tank range. This is further facilitated by a compressible gasket 73 described hereinafter that is formed to assist in compensating for differences in the fixed sweep of the 30 external adaptor plate and the various sweeps of the water tank range. Typically, the external adaptor plate 65 is manufactured from a zinc alloy for the purposes of fire resistance. It can also be manufactured from other metallic or non-metallic fire resistant materials. 35 (d) A lock nut 69 (Figures 13-18), which is typically a left handed thread matching that of the WO 2008/141374 PCT/AU2008/000700 - 27 spigot/shaft 53 of the main outlet body 49, that is adapted to engage the external adaptor plate 65 and then compresses the main outlet body 49 against the internal adaptor plate 57. This assembly, in turn, compresses 5 against the tank shell and is balanced by the compression forces generated by the nut 69 against the external adaptor plate 65. This assembly, in turn, via the compressible gasket 73, compresses the outer surface of the corrugated outer shell. The end result is that the 10 threaded engagement of the nut 69 with the spigot/shaft 53 is to force the external and internal adapter plates against the external and internal surfaces of the tank shell. Typically, and for the same reasons as the spigot/shaft 53 and the external adaptor plate 65, this 15 component is manufactured from a zinc alloy but is not restricted to such a material choice where other metallic or non-metallic materials with fire resistance characteristics could also be suitable for this application. 20 (e) A compressible gasket 73 is used in conjunction with the external adaptor plate 65 to make a smooth transition from a common profile in plan view of the above-mentioned external adaptor plate and the 25 different sweeps of the outer surface of the tank shell. Typically, this component is constructed from moulded Seblex polyolefin elastomer. This component could be made from any suitable material. 30 C. The overflow sub-system - Figures 39-65. The overflow sub-system 77 comprises five individual components that fit together to form the assembled sub-system shown in Figures 39-44, as described 35 below: (a) A weld ring 79 that is fusion welded to the WO 2008/141374 PCT/AU2008/000700 - 28 end bag or bags positioned in the tank shell. The weld ring 79 is typically made from a polyethylene. The weld ring 79 comprises an oval flange 81 that provides a flat weld surface and a sleeve 83 that extends from an inner 5 edge of the flange 81. The flange 81 also provides a surface on which a compression gasket 95 described hereinafter seals the weld ring 79 to the body of the overflow sub-system described hereinafter. The sleeve 83 is designed to be a female type engagement such that the 10 overflow body male engagement fits inside the spout of the weld ring 79. (b) An overflow body 85 that has an oval sleeve 87 with outwardly operable snap lock fittings 89 is 15 designed to engage with the sleeve 83 of the weld ring 79. The dimensions, including the lengths of the sleeves 87, 83 are selected so that the sleeve 83 of the weld ring 79 can extend into the sleeve 87 of the overflow body 85 and the snap lock fittings 89 of the overflow body 85 can 20 engage the flange 81 of the weld ring 79 and retain the two components together. The assembly of the two components together also relies on the compressive characteristics of the compression seal gasket 95 described hereinafter to preload the snap lock fittings 25 89. The overflow body 85 has a cross sectional transition 93 from oval to round that provides for the same cross sectional area from inner to outer shape (oval to round) and provides for additional volume retention inside the tank by virtue of the bottom invert of the overflow body 30 85 being substantially higher on the inside of the tank than the bottom invert of the overflow body 85 on the outside of the tank. When positioned in relation to the tank, the overflow body 85 transitions from inside the tank shell to the outside of the outer shell by passing 35 through the shell surface and has a number, typically four, screw bosses that engage on the inner surface of the outer shell regardless of the sweep of the tank. This is WO 2008/141374 PCT/AU2008/000700 - 29 achieved by a combination of sweep detail in the plan view of the overflow body and the location and dimensional depth of the screw bosses that allow the positive location of the bosses on the inner surface of the tank shell at 5 all times independent of the sweep of the tank. The overflow is typically constructed from an ultraviolet stabilised poly vinyl chloride (PVC), which allows it to be connected to standard external plumbing accessories by solvent welding. The inner surface of the overflow body 10 85 also transitions gently to the inner surface of the tank inner shell such that the bag flows over the face of the component not to induce stress into the bag under hydrostatic load conditions. 15 (c) An inner compression gasket 95 that seals the weld ring flange 81 to the back end (inner side) of the overflow body 85 to prevent water ingress from the bag to the inner tank shell as well as providing preload for the snap lock fasteners on the overflow body to the weld 20 ring sleeve 79. Typically, this component is constructed from a moulded Seblex polyolefin elastomer compound but is not restricted to this material and as with all gaskets described herein can be constructed from any material whose mechanical and short and long-term durability 25 performance characteristics meet the requirements of the application. (d) An outer compression gasket 97 is used in conjunction with the external locking ring described 30 hereinafter to make a smooth transition from a common profile in plan view of the external locking ring and the four different sweeps of the outer surface of the tank shell. Typically, this component is constructed from moulded Seblex polyolefin elastomer but is not restricted 35 to this material and as with all gaskets in this document can be constructed from any material whose mechanical and short and long-term durability performance characteristics WO 2008/141374 PCT/AU2008/000700 - 30 meet the requirements of the application. (e) An external retaining ring 99 having an inner surface 101 that has a wave-type profile that mates 5 to the outer profile of the corrugated tank shell and provides a transition from the corrugation profile to flat outer or outboard surface. An important feature of the external retaining ring 99 is that the profile in plan view is such that it is a common component that suits all 10 four sweeps of the tank range. This is further facilitated by the above component, a compressible gasket, to assist in compensating for the difference in the fixed sweep of the external locking ring inner surface and the various sweeps of the water tank range. Typically, the 15 external retaining ring is manufactured from ultraviolet stabilised polypropylene. It can also be manufactured from other non-metallic or metallic materials suitable for this application. The external retaining ring 99 is assembled to the overflow body 85 by a number, typically 20 four, of "high-low" screw fixings, typically stainless steel, extending into the corresponding four off-bosses of the overflow body. This attachment procedure then holds the overflow sub-assembly rigidly to the tank shell by compression, which in turn locates and restrains the bag 25 at this specific location. While a number of embodiments of the fittings in accordance with the present invention have been described, it will be appreciated by persons skilled in the art that 30 numerous variations and/or modifications may be made to the invention without departing from the spirit or scope of the invention as broadly described. The embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. 35

Claims

1. An inlet sub-system for allowing the passage of water into a water storage tank, the tank comprising an 5 outer shell that defines an interior of the tank and has an opening for receiving the inlet subsystem and at least one water catchment bag located in the tank interior, the inlet sub-system comprising: 10 (a) a weld ring that can be positioned inside the outer shell of the tank and affixed to the bag, , (b) a retaining ring that can be connected to the weld ring and is adapted to extend through the opening 15 in the tank shell, (c) an inlet/strainer that can be connected to the retaining ring and positioned to extend across the opening in the tank shell, and 20 (d) a light guard for allowing the passage of water but restricting the passage of ultraviolet light into the tank that is separate to the retaining ring but is formed to be housed within and mounted to the retaining 25 ring and is retained in position by the inlet/strainer when the inlet/strainer is connected to the light guard.

2. The inlet sub-system defined in claim 1 further comprises a compression gasket for preventing leakage of 30 water from inside the bag through the inlet system connections to a cavity between the outside of the bag and the inside of the outer shell.

3. The inlet sub-system defined in claim 1 or claim 35 2 wherein the weld ring and the retaining ring have complementary quick release fixings that allow the weld ring and the retaining ring to be quickly and efficiently WO 2008/141374 PCT/AU2008/000700 - 32 coupled together.

4. The inlet sub-system defined in any one of the preceding claims wherein the inlet/strainer and the 5 retaining ring have complementary quick release fixings that allow the inlet/strainer and the retaining ring to be quickly and efficiently coupled together.

5. The inlet sub-system defined in any one of the 10 preceding claims wherein the weld ring comprises an annular flange that has a flat surface for welding to the bag and a vertical shank with quick release fixings in the form of spaced-apart bayonet fixings that are adapted to connect the weld ring to a mating part of the retaining 15 ring.

6. The inlet sub-system defined in any one of the preceding claims wherein the retaining ring comprises an annular flange that contacts an outside surface of the 20 tank shell and a cylindrical sleeve that extends from the flange through the opening in the tank shell.

7. The inlet sub-system defined in claim 6 wherein the cylindrical sleeve terminates in an inwardly and 25 upwardly extending lip that defines a channel for receiving the light guard.

8. The inlet sub-system defined in claim 7 wherein the light guard comprises an outer peripheral flange that 30 can be positioned to extend into the channel in the retaining ring.

9. An outlet sub-system for allowing the passage of water from a water storage tank, the tank comprising an 35 outer shell that defines an interior of the tank and has an opening for receiving the outlet sub-system and at least one water catchment bag located in the tank WO 2008/141374 PCT/AU2008/000700 - 33 interior, the outlet sub-system comprising:. (a) a main outlet body having a weld ring that can be positioned inside the outer shell of the tank and 5 affixed to the bag and a threaded spigot or shaft that defines a support member for the weld ring and is adapted to extend through the opening in the tank shell and to allow the attachment of a plug or tap or other plumbing fittings that allows water flow from within the tank to 10 outside the tank to be controlled or directed, (b) an internal adaptor plate that is adapted to orientate the outlet body within the tank shell and to contact an inside surface of the tank shell, 15 (c) an external adaptor plate that is formed with a profile to mate an outer profile of the tank shell, and 20 (d) a lock nut that is adapted to engage the spigot or shaft of the main outlet body to force the external adaptor plate against an outer surface of the tank shell and to force the internal adaptor plate against the tank shell. 25

10. The outlet sub-system defined in claim 9 further comprises a compressible gasket adapted to be positioned between the outer surface of the outer shell and the external adaptor plate. 30

11. The outlet sub-system defined in claim 9 or claim 10 wherein the main outlet body and the internal adaptor plate each comprise complementary components that allow mechanical key inter-engagement to assist in the 35 prevention of relative rotational movement of the weld ring and the spigot/shaft whilst under a torsional load. WO 2008/141374 PCT/AU2008/000700 - 34

12. The outlet sub-system defined in any one of claims 9 to 11 wherein, when the tank shell comprises corrugated side walls and end walls, the internal adaptor 5 plate has a mating wave-type profile that conforms to the internal corrugations of the tank shell.

13. The outlet sub-system defined in any one of claims 9 to 12 wherein, when the tank shell comprises 10 corrugated side walls and end walls, the external adaptor plate is formed so that the profile in plan view is such that it is a common component that suits a range of sweeps of the tank range. 15

14. An overflow outlet sub-system for allowing the passage of water from a water storage tank, the tank comprising an outer shell that defines an interior of the tank and has an opening for receiving the overflow outlet sub-system and at least one water catchment bag located in 20 the tank interior, the overflow outlet sub-system comprising: (a) a weld ring that is adapted to be welded to the end bag or bags positioned in the tank shell, the weld 25 ring comprising a flange that provides a flat weld surface and a sleeve, (b) an overflow body that has a sleeve adapted to engage with the sleeve of the weld ring and to extend 30 through the opening in the tank shell, and (c) an external retaining ring having an inner surface that has a profile that is adapted to mate to an outer profile of the tank shell. 35

15. The overflow outlet sub-system defined in claim 14 further comprises an inner compression gasket that is WO 2008/141374 PCT/AU2008/000700 - 35 adapted to seal the weld ring flange to the overflow body to prevent water ingress from the bag to the inner tank shell. 5

16. The overflow outlet sub-system defined in claim 14 or claim 15 wherein the overflow body comprises snap lock fittings and the dimensions of the sleeves of the overflow body and the weld ring are selected so that the sleeve of the weld ring can extend into the sleeve of the 10 overflow body and the snap lock fittings of the overflow body can engage the flange of the weld ring and retain the two components together.

17. A water storage tank that comprises an outer 15 shell that defines an interior of the tank and has a plurality of openings, at least one water catchment bag located in the tank interior, and any one or more than one of the fittings defined in any one of the preceding claims connected as required to the outer shell and the bag or 20 bags.

18. The tank defined in claim 17 wherein there are two inlet sub-systems connected to openings in the tank and to the bag in the tank. 25

19. The tank defined in claim 17 or claim 18 wherein the bag is a self-supporting bag.

20. The tank defined in any one of claims 17 to 19 30 wherein the outer shell comprises side walls and end walls and the bag is fabricated from flexible sheet material that is impervious to passage of water or other liquid and the bag having a structure such that when the bag is installed within the tank shell and filled with liquid, 35 the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.