GB2551981A

GB2551981A - Tank

Info

Publication number: GB2551981A
Application number: GB1611443.1A
Authority: GB
Inventors: Shuttleworth Andrew; Griffiths Cedric
Original assignee: SEL ENVIRONMENTAL Ltd
Current assignee: SEL ENVIRONMENTAL Ltd
Priority date: 2016-06-30
Filing date: 2016-06-30
Publication date: 2018-01-10
Anticipated expiration: 2036-06-30
Also published as: GB2551981B; GB201611443D0

Abstract

A tank 10 is provided for subterranean installation. The tank 10 includes a frame 20 and a barrier member 30. The frame 20 is arranged to support the barrier member 30. The barrier member 30 is designed to contain a liquid, when in use. The reservoir has an inlet 40 and an outlet 50. The tank further includes a restrictor 60 arranged to restrict, in use, a flow of water through the outlet 50. The tank may comprise a plurality of subframes and the barrier member may be manufactured out of one or more types of thermoplastic polymers. The wall elements may be porous or impermeable. The tank may comprise a filter. A kit and a method for mounting the tank are also disclosed.

Description

(54) Title of the Invention: Tank

Abstract Title: Underground water storage and drainage tank.

(57) A tank 10 is provided for subterranean installation. The tank 10 includes a frame 20 and a barrier member 30. The frame 20 is arranged to support the barrier member 30. The barrier member 30 is designed to contain a liquid, when in use. The reservoir has an inlet 40 and an outlet 50. The tank further includes a restrictor 60 arranged to restrict, in use, a flow of water through the outlet 50. The tank may comprise a plurality of subframes and the barrier member may be manufactured out of one or more types of thermoplastic polymers. The wall elements may be porous or impermeable. The tank may comprise a filter. A kit and a method for mounting the tank are also disclosed.

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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Tank

Field

The present invention relates to tanks and to methods of manufacture of tanks for receiving and discharging fluids. In particular, the present invention relates to a tank arranged to control discharge of a fluid received therein.

Background to the Invention

Discharge of surface water into a drainage system may be regulated. Surface water includes water from precipitation such as rain or snow falling on a property or curtilage that has not seeped into the ground, for example, and is discharged into the drainage system. A flow rate capacity of the drainage system may, for example, be sufficient for surface water resulting from typical rainfalls. However, the flow rate capacity of the drainage system may, for example, be insufficient for surface water resulting from atypical rainfalls, such as sustained rainfall or storms. That is, a discharge flow rate of surface water into the drainage system may be in excess of the flow rate capacity of the drainage system. So as not exceed the flow rate capacity of the drainage system, discharge of surface water from residential, commercial, industrial or agricultural property or curtilage into the drainage system may be controlled by mandating maximum discharge flow rates of surface water into the drainage system. The maximum discharge flow rates of surface water into the drainage system may be according to, for example, the flow rate capacity of the drainage system, a volume of surface water, a type or size of property or an area of curtilage. For example, a maximum discharge flow rate of surface water into the drainage system for a typical residential property may be mandated around 0.2 dm’s'¹. Typically, restrictors such as flow control devices may be provided to restrict maximum discharge flow rates of surface water into drainage systems. However, since surface water may be received by a property and/or curtilage at a rate higher than a mandated maximum rate of discharge into the drainage system, surface water may accumulate on or in the property and/or curtilage. Typically, tanks may be provided upstream of restrictors to hold accumulated surface water. The accumulated surface water may discharge at flow rates controlled by the restrictors and may, for example, continue to discharge after rain has lessened or ceased. In this way, restrictors and tanks together provide attenuation of surface water discharged into drainage systems, limiting peak flow rates and increasing durations of flow into the drainage systems.

However, known restrictors and tanks may require relatively complex and/or costly installations while maintenance may be problematic. For example, a depth of a drainage system below the ground may determine a depth or height of a restrictor and/or a depth or height of a tank upstream of the restrictor, such that sufficient fall to the drainage system is provided. For example, tanks may be provided above the ground, which may not be preferred or permitted. Alternatively, tanks may be provided below the ground, requiring extensive excavation. Additionally, pumps may be required to pump accumulated surface water from the subterranean tanks, for example. Coupling between tanks and/or restrictors may be relatively complex while leakage may occur at couplings. Solids, such as suspended solids or debris may be deposited in the tanks. Blockages may require remedial action. Inspection may require specialist tools.

Hence, there is a need to improve attenuation of surface water discharged into drainage systems.

Summary of the Invention

It is one aim of the present invention, amongst others, to provide a tank which at least partially obviates or mitigates at least some of the disadvantages of the prior art, whether identified herein or elsewhere. In this way, attenuation of surface water discharged into drainage systems may be improved.

A first aspect of the invention provides a tank for subterranean installation, the tank comprising a frame and a barrier member;

wherein the frame is arranged to support the barrier member and the barrier member is arranged to define a volume to receive a fluid, in use; wherein the tank comprises an inlet and an outlet; and wherein the tank comprises a restrictor arranged to restrict, in use, a flow of the fluid through the outlet.

A second aspect of the invention provides a kit of parts for a tank for subterranean use, the kit of parts comprising: a frame and a barrier member;

wherein the frame is arranged to support the barrier member and the barrier member is arranged to define a volume to receive a fluid, in use; an inlet and an outlet; and a restrictor arranged to restrict, in use, a flow of the fluid through the outlet.

A third aspect of the invention provides a tank assembly, comprising a tank and a filter box, the tank comprising a frame and a barrier member;

wherein the frame is arranged to support the barrier member and the barrier member is arranged to define a volume to receive a fluid, in use;

wherein the tank comprises an inlet and an outlet; and wherein the tank comprises a restrictor arranged to restrict, in use, a flow of the fluid through the outlet; and wherein the filter box is coupleable to the inlet.

A fourth aspect of the invention provides a method of manufacturing a tank for subterranean use, the method comprising:

providing a frame and a barrier member;

supporting the barrier member by the frame, wherein the barrier member is arranged to define a volume to receive a fluid, in use; providing an inlet and an outlet; and providing restrictor arranged to restrict, in use, a flow of the fluid through the outlet.

A fifth aspect of the invention provides a method of installing a tank for subterranean use, the tank comprising a frame and a barrier member;

wherein the frame is arranged to support the barrier member and the barrier member is arranged to define a volume to receive a fluid, in use; wherein the tank comprises an inlet and an outlet; and wherein the tank comprises a restrictor arranged to restrict, in use, a flow of the fluid through the outlet;

the method comprising:

coupling the outlet directly to a drainage system.

Detailed Description of the Invention

According to the present invention there is provided a tank and a kits of parts for a tank, as set forth in the appended claims. Also provided is a method of manufacturing a tank and a method of installing a tank. Other features of the invention will be apparent from the dependent claims, and the description that follows.

Throughout this specification, the term “comprising” or “comprises” means including the component(s), unit(s), module(s), feature(s) or integer(s) specified but not to the exclusion of the presence of other components, units, modules, features or integers.

The term “consisting of’ or “consists of’ means including the component(s), unit(s), module(s), feature(s) or integer(s) specified but excluding other components, units, modules, features or integers.

Whenever appropriate, depending upon the context, the use of the term “comprises” or “comprising” may also be taken to include the meaning “consists essentially of” or “consisting essentially of’, and also may also be taken to include the meaning “consists of’ or “consisting of’.

The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each aspect or exemplary embodiment of the invention, as set out herein are also applicable to all other aspects or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each aspect or exemplary embodiment of the invention as interchangeable and combinable between different aspects and exemplary embodiments.

The first aspect of the invention provides a tank for subterranean installation, the tank comprising a frame and a barrier member;

In this way, attenuation of surface water discharged into drainage systems may be improved. Particularly, installation of the tank may be simplified compared with conventional installations because the restrictor is arranged in the tank, for example within, wholly within the tank. In this way, additional excavation required fora conventional restrictor downstream of a conventional tank is avoided, for example, reducing complexity and/or cost of parts and/or installation. Further, couplings such as pipes required between conventional tanks and conventional restrictors are also eliminated, further reducing complexity and/or cost of parts and/or installation and improving reliability. In this way, the tank may be more efficiently installed at both existing and new properties and/or curtilages. In addition, by providing the frame to support the barrier member, tanks having different volumes may be more readily manufactured, as required. Furthermore, tanks suitable for subterranean installation may be more readily and/or economically manufactured.

It should be understood that the fluid may comprise a liquid, for example water or surface water. It should be understood that water and/or surface water may comprise solids for example suspended solids such as organic or inorganic particulates and/or debris including non-buoyant debris such as stones, sand or soil and/or buoyant debris such as leaves or wood. It should be understood that water and/or surface water may comprise contaminants for example liquid contaminants such as oil. It should be understood that the fluid may comprise a gas, for example air.

In an example embodiment, the tank is a subterranean tank for subterranean installation.

It should be understood that the frame is arranged to support the barrier member. That is, the frame may reinforce or strengthen the barrier member, for example. In an example embodiment, the frame is arranged to resist a load. The frame may be arranged to resist an internal and/or an external load. The frame may be arranged to resist loads in one, two or three orthogonal directions. The frame may be arranged to resist external loads in one, two or three orthogonal directions. For example, the frame may be arranged to resist a weight of material such as aggregate, sand, soil or paving provided above the tank, in use. For example, the frame may be arranged to resist an inward load due to such material around a tank, in use. The frame may be arranged to resist internal loads in one, two or three orthogonal directions. For example, the frame may be arranged to resist a weight of fluid received in the volume, in use. For example, the frame may be arranged to resist an outward load due to the fluid received in the volume, in use. The frame may comprise a tie and/or a strut, arranged to resist a load. The frame may comprise a plurality of ties and/or struts, arranged to resist loads in one, two or three orthogonal directions.

In an example embodiment, the inlet comprises a first passageway arranged in the barrier member. In an example embodiment, the outlet comprises a second passageway arranged in the barrier member.

In an example embodiment, the inlet is arranged at an invert level (i.e. lower level, in use) of the tank. In an example embodiment, the inlet is arranged at a soffit or crown level (i.e. upper level, in use) of the tank. In an example embodiment, the outlet is arranged at an invert level of the tank. In an example embodiment, the outlet is arranged at a soffit or crown level of the tank. In an example embodiment, the inlet is arranged at a level of the tank and the outlet is arranged at the same level of the tank. In an example embodiment, the inlet is arranged at an invert level of the tank and the outlet is arranged at the invert level of the tank.

In an example embodiment, the tank comprises a plurality of inlets. For example, the tank may comprise two, three, four or more inlets. In an example embodiment, the tank comprises a plurality of outlets. For example, the tank may comprise two, three, four or more outlets. In an example embodiment, the tank comprises only one outlet.

In an example embodiment, the frame is arranged to define a planar wall portion. The frame may be arranged to define a non-planar wall portion, for example a curved wall portion. In an example embodiment, the frame is arranged to define a first or lower wall portion. In use, the lower wall portion may be arranged lowermost for example horizontally, providing a base for the tank. The frame may be arranged to define a second or upper wall portion, spaced apart from the lower wall portion. In use, the upper wall portion may be arranged uppermost for example horizontally, providing a roof for the tank. The frame may be arranged to define a third or side wall portion, arranged, for example extending, between the lower wall portion and the upper wall portion, for example between edges of the lower wall portion and the upper wall portion. The frame may be arranged to define a plurality of side wall portions, for example two opposed side wall portions or two pairs of opposed side wall portions. In use, the side wall portions may be arranged vertically, providing side walls for the tank. In an example embodiment, the frame is arranged to define a symmetrical tank form, for example a cuboidal or a cubic tank form. In an example embodiment, the frame is arranged to define a first or lower wall portion, a second or upper wall portion opposed to the lower wall portion and two pairs of opposed side wall portions, arranged between the lower wall portion and the upper wall portion, for example between edges of the lower wall portion and the upper wall portion, and wherein adjacent wall portions are arranged mutually orthogonally.

In an example embodiment, the frame comprises a planar wall portion. The frame may comprise a non-planar wall portion, for example a curved wall portion. In an example embodiment, the frame comprises a first or lower wall portion. In use, the lower wall portion may be arranged lowermost for example horizontally, providing a base for the tank. The frame may comprise a second or upper wall portion, spaced apart from the lower wall portion. In use, the upper wall portion may be arranged uppermost for example horizontally, providing a roof for the tank. The frame may comprise a third or side wall portion, arranged, for example extending, between the lower wall portion and the upper wall portion, for example between edges of the lower wall portion and the upper wall portion. The frame may comprise a plurality of side wall portions, for example two opposed side wall portions or two pairs of opposed side wall portions. In use, the side wall portions may be arranged vertically, providing side walls for the tank, for example. In an example embodiment, the frame comprises a symmetrical tank form, for example a cuboidal or a cubic tank form. In an example embodiment, the frame comprises a first or lower wall portion, a second or upper wall portion opposed to the lower wall portion and two pairs of opposed side wall portions, arranged, for example extending, between the lowerwall portion and the upper wall portion, for example between edges of the lower wall portion and the upper wall portion, and wherein adjacent wall portions are arranged mutually orthogonally. In an example embodiment, adjacent wall portions may be coupled, for example mechanically coupled using clips or fasteners, adhesively coupled or welded. In an example embodiment, the wall portions may be formed together, for example by casting or moulding.

In an example embodiment, the frame comprises an internal tie and/or a strut arranged, for example extending, between two wall portions. The internal tie and/or strut may extend between two opposed wall portions, for example between the lower wall portion and the upper wall portion. In an example embodiment, the frame comprises a plurality of internal ties and/or struts arranged, for example extending, between two wall portions.

In an example embodiment, the tank comprises a cuboidal tank form, having a height in a range 0.1 to 0.6 m for example 0.4 m, a width in a range 0.5 to 4 m for example 2 m and a length in a range 0.5 to 4 m for example 2 m. In this way, the tank may have a relatively low height for a given size, allowing the tank to be installed in relatively shallow excavations. Relatively shallow excavations may avoid or reduce disturbing features and/or properties of the ground and/or services, such as pipes or cables, in the ground. Additionally and/or alternatively, coupling to relatively shallow drainage systems may be possible while maintain a sufficient gradient without pumping, for example. In this way, cost and/or complexity of installation may be reduced.

In an example embodiment, the frame comprises a subframe, for example a cage, a crate, a replacement module or a geo-cellular unit. In an example embodiment, the frame consists of a subframe, as described above. In an example embodiment, the frame comprises a plurality of subframes, as described above. The subframes may be arranged in an assembly of adjacent subframes, wherein the assembly defines the frame. The subframes may be modular, arranged for modular assembly. Adjacent subframes may be coupled, for example mechanically coupled using clips or fasteners, adhesively coupled or welded. The subframes may be coupled, for example mechanically coupled using banding. The subframes may comprise interlocking members for coupling and the adjacent subframes may be coupled by the interlocking members. The subframes may be provided of a similar, for example a same, size. Conversely, the subframes may be provided of differing, for example fractional, sizes. In this way, the frame may be readily assembled from modular subframes, for example.

In an example embodiment, the subframe comprises a planar wall portion. The subframe may comprise a non-planar wall portion, for example a curved wall portion. In an example embodiment, the subframe comprises a first or lower wall portion. In use, the lower wall portion may be arranged lowermost for example horizontally, providing a base for the subframe. The subframe may comprise a second or upper wall portion, spaced apart from the lower wall portion. In use, the upper wall portion may be arranged uppermost for example horizontally, providing a roof for the subframe. The subframe may comprise a third or side wall portion, arranged, for example extending, between the lower wall portion and the upper wall portion, for example between edges of the lower wall portion and the upper wall portion. The subframe may comprise a plurality of side wall portions, for example two opposed side wall portions or two pairs of opposed side wall portions. In use, the side wall portions may be arranged vertically, providing side walls for the tank, for example. In an example embodiment, the subframe comprises a symmetrical form, for example a cuboidal or a cubic form. In an example embodiment, the subframe comprises a first or lower wall portion, a second or upper wall portion opposed to the lower wall portion and two pairs of opposed side wall portions, arranged, for example extending, between the lower wall portion and the upper wall portion, for example between edges of the lower wall portion and the upper wall portion, and wherein adjacent wall portions are arranged mutually orthogonally. In an example embodiment, adjacent wall portions may be coupled, for example mechanically coupled using clips or fasteners, adhesively coupled or welded. In an example embodiment, the wall portions may be formed together, for example by casting or moulding.

In an example embodiment, the subframe comprises an internal tie and/or a strut arranged, for example extending, between two wall portions. The internal tie and/or strut may extend between two opposed wall portions, for example between the lower wall portion and the upper wall portion. In an example embodiment, the subframe comprises a plurality of internal ties and/or struts arranged, for example extending, between two wall portions.

In an example embodiment, the frame comprises a passageway, for example a perforation. The frame may comprises a plurality of passageways, for example a plurality of perforations. In an example embodiment, a frame wall portion as described above, for example a lower wall portion, an upper wall portion, a side wall portion, may comprise a passageway and/or a plurality of passageways. In an example embodiment, these passageways are interconnected. In this way, the fluid may communicate, for example flow or freely flow, through the frame, in use.

In an example embodiment, the frame has an effective perforated surface area of more than 30%, more than 35%, more than 40%, more than 45%, more than 50% or more than 55%. In this way, the fluid may communicate, for example flow or freely flow, through the frame, in use.

In an example embodiment, the frame has a Volumetric Void Ratio (VVR) of more than 75%, more than 80%, more than 85%, more than 90% or more than 95%. In this way, the tank may define a relatively large volume to receive the fluid compared with a volume of the tank.

In an example embodiment, the subframe comprises a passageway, for example a perforation. The subframe may comprises a plurality of passageways, for example a plurality of perforations. In an example, a subframe wall portion as described above, for example a lower wall portion, an upper wall portion, a side wall portion, may comprise a passageway and/or a plurality of passageways. In an example embodiment, these passageways are interconnected.

In this way, the fluid may communicate, for example flow or freely flow, through the subframe, in use. In an example embodiment, these passageways are interconnectable between adjacent subframes. In this way, the fluid may communicate, for example flow or freely flow, between adjacent subframes in an assembly of subframes as described above, in use.

In an example embodiment, the subframe has an effective perforated surface area of more than 30%, more than 35%, more than 40%, more than 45%, more than 50% or more than 55%. In this way, the fluid may communicate, for example flow or freely flow, through the subframe, in use.

In an example embodiment, the subframe has a Volumetric Void Ratio (VVR) of more than 75%, more than 80%, more than 85%, more than 90% or more than 95%. In this way, the tank may define a relatively large volume to receive the fluid compared with a volume of the tank.

In an example embodiment, the tank has a Volumetric Void Ratio (VVR) of more than 75%, more than 80%, more than 85%, more than 90% or more than 95%. In this way, the tank may define a relatively large volume to receive the fluid compared with a volume of the tank.

In an example embodiment, the frame and/or subframe comprises a first polymeric composition comprising a first thermoplastic polymer.

In an example embodiment, the barrier member comprises a second polymeric composition comprising a second thermoplastic polymer.

The first polymeric composition and the second polymeric composition may be the same or different. The first thermoplastic polymer and the second thermoplastic polymer may be the same or different.

Polymeric compositions comprising thermoplastics may be readily formed, for example by extrusion, moulding or injection moulding, to provide the described frame and/or subframe. Such polymeric compositions may have appropriate mechanical properties suitable for subterranean installations, including loads as described above. Such polymeric compositions may have appropriate chemical properties suitable for resistance to the environment. For example, such polymeric compositions may be resistant to chemicals, such as oils and/or leachates. In addition, such polymeric compositions may be stabilised for resistance to UV light and/or ozone, for example.

The first thermoplastic polymer and/or the second thermoplastic polymer may be selected from a group consisting of poly(methyl methacrylate) (PMMA), acrylonitrile butadiene styrene (ABS), aliphatic or semi-aromatic polyamides, polylactic acid (polylactide) (PLA), polybenzimidazole (PBI), polycarbonate (PC), polyether sulfone (PES), polyetherimide, polyethylene (PE), polypropylene (PP), polymethylpentene (PMP) and polybutene-1 (PB-1), polystyrene (PS) and polyvinyl chloride (PVC). A preferred first thermoplastic polymer is polypropylene (PP). A preferred second thermoplastic polymer is polyethylene (PE).

The first thermoplastic polymer and/or the second thermoplastic polymer may be a thermoplastic polyolefin. The thermoplastic polyolefin may be selected from a group consisting of: polyethylene (PE), polypropylene (PP), polymethylpentene (PMP) and polybutene-1 (PB-1). A preferred thermoplastic polyolefin for the second thermoplastic polymer is polyethylene (PE).

In an example embodiment, the first thermoplastic polymer is polypropylene (PP).

In an example embodiment, the second thermoplastic polymer is polyethylene (PE).

The polyethylene may have a density range of 0.880-0.940 g/cm³. The polyethylene may have a density >0.940 g/cm³.

The polyethylene may be selected from a group consisting of high-density polyethylene (HDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), lowdensity polyethylene (LDPE) and very-low-density polyethylene (VLDPE).

In an example embodiment, the second thermoplastic polymer is high-density polyethylene (HDPE).

The polyethylene may have a crystallinity of more than 30%, more than 35%, more than 40%, more than 45%, more than 50%, more than 55%, more than 60%, more than 65%, more than 70%, more than 75%, more than 80%, more than 85%, more than 90%.

The PE may be copolymerised with, for example, but-1-ene or hex-1-ene.

The first polymeric composition and/or the second polymeric composition may comprise additives, such as fillers and/or colourants.

In an example embodiment, the frame and/or subframe comprises a metal, for example an alloy such as a steel, stainless steel or an aluminium alloy.

In an example embodiment, the frame and/or the subframe is a geo-cellular unit comprising polypropylene (PP), having a load bearing capacity of 700 kPa.

In an example embodiment, the barrier member is arranged to define the volume in a range 0.2 to 20 m³, for example 1.5 m³ or more. In this way, the tank may receive atypical surface water for a typical residential property.

In an example embodiment, a portion of the barrier member is arranged externally with respect to the frame. In an example embodiment, the barrier member is arranged externally with respect to the frame. In an example embodiment, the tank comprises an internal frame and an external barrier member. For example, the barrier member may be arranged to surround, completely surround, enclose, completely enclose, envelope, completely envelope or encapsulate the frame. For example, the frame may be arranged within or wholly within the barrier member. That is, the barrier member may overlay the frame.

Conversely, in an example embodiment, a portion of the barrier member is arranged internally with respect to the frame. In an example embodiment, the barrier member is arranged internally with respect to the frame. In an example embodiment, the tank comprises an external frame and an internal barrier member. For example, the frame may be arranged to surround, completely surround, enclose, completely enclose, envelope, completely envelope or encapsulate the barrier member. For example, the barrier member may be arranged within or wholly within the frame.

In an example embodiment, the barrier member comprises an impermeable barrier member, for example a sheet, a membrane, a geomembrane, a liner or a shell. It should be understood that the impermeable barrier member may comprise no passageways or may comprise only the first and second passageways, as described above, and/or passageways as described below with respect to a port and/or a secondary outlet. In this way, fluid may be prevented from flowing into and/or out of the tank through the impermeable barrier member. For example, water received in the volume may be accumulated for example held, retained or stored in the volume. In an example embodiment, the barrier member comprises an impermeable barrier member arranged to accumulate a portion of the received fluid, in use. In an example embodiment, the barrier member comprises an impermeable barrier member arranged to accumulate the received fluid, in use. The impermeable barrier member may be arranged to surround, completely surround, enclose, completely enclose, envelope, completely envelope or encapsulate the frame, as described above. The impermeable barrier member may comprise the first polymeric composition comprising the first thermoplastic polymer, as described above. The impermeable barrier member may comprise polypropylene (PP), as described above. The impermeable barrier member may comprise the second polymeric composition comprising the second thermoplastic polymer, as described above. The impermeable barrier member may comprise high-density polyethylene (HDPE), as described above. The impermeable barrier member may comprise a sheet or a membrane, having a thickness in a range 0.5 to 1.5 mm, for example 1.0 mm. Sheets or membranes may be cut to size and being relatively flexible or drapable, may be arranged to wrap and/or fold around the frame, so as to surround, completely surround, enclose, completely enclose, envelope, completely envelope or encapsulate the frame, as described above. Furthermore, sheets or membranes comprising a polymeric composition as described above may be coupled by adhesive coupling or welding, such as solvent or thermal welding, for example. In an example embodiment, the impermeable barrier member comprises a polypropylene geomembrane, having a thickness of 1.0 mm. The impermeable barrier member may comprise a liner or shell for example a moulded or rotationally moulded shell, having a thickness in a range 0.5 to 5 mm. For example, shells may be provided to surround, completely surround, enclose, completely enclose, envelope, completely envelope or encapsulate the frame, as described above, and/or liners may be provided to be received in the frame, as described above. Such liners or shells may be relatively more robust than the sheets or membranes described, such that an integrity of the barrier member may be improved. For example, a watertightness of the barrier member may be improved. In this way, the tank may be suitable for installation in relatively impervious ground, under impervious surfacings or where the water table is relatively high, for example.

In an example embodiment, the barrier member comprises a permeable barrier member, for example a sheet, a textile, a non-woven textile, a woven textile or a geotextile. The permeable barrier member may comprise perforations, such as formed by punching. In this way, fluid may flow into and/or out of the tank through the permeable barrier member. For example, water may permeate into the tank and/or received water may permeate out of the tank through the permeable barrier member. For example, air may flow out of the tank while water is received in the volume. In an example embodiment, permeability of the permeable barrier member provides the first and/or second passageway, as described above. The permeable barrier member may comprise the first polymeric composition comprising the first thermoplastic polymer, as described above. The permeable barrier member may comprise polypropylene (PP), as described above. The permeable barrier member may comprise the second polymeric composition comprising the second thermoplastic polymer, as described above. The permeable barrier member may comprise high-density polyethylene (HDPE), as described above. The sheet or membrane may have a mass per unit area in a range of 0.2 to 0.5 kgm'², for example 0.3 kgm². Sheets or membranes may be cut to size and being relatively flexible or drapable, may be arranged to wrap and/or fold around the frame, so as to surround, completely surround, enclose, completely enclose, envelope, completely envelope or encapsulate the frame, as described above. Furthermore, sheets or membranes comprising a polymeric composition as described above may be coupled by adhesive coupling or welding, such as solvent or thermal welding, for example. In an example embodiment, the permeable barrier member comprises a non-woven, needle-punched polypropylene geotextile, having a mass per unit area of 0.3 kgm². In this way, the tank may be suitable for installation in relatively pervious ground or where the water table is relatively low, for example.

In an example embodiment, the barrier member comprises an impermeable barrier member, as described above, and a permeable barrier member, as described above. For example, the permeable barrier member may be arranged proximal an upper wall portion of the frame, as described above. For example, the permeable barrier member may be arranged to extend across the upper wall portion of the frame, between upper edges of opposed side walls of the frame. For example, the impermeable barrier member may be arranged proximal a lower wall portion and/or side wall portions of the frame, as described above. For example, the impermeable barrier member may be arranged to surround, completely surround, enclose, completely enclose, envelope, completely envelope or encapsulate the lower wall portion and the side wall portions of the frame. In this way, fluid may flow, for example permeate down, into the tank through the permeable barrier member while the fluid received in the volume may be accumulated for example held, retained or stored in the volume.

In an example embodiment, the barrier member is coupled to the frame. In an example embodiment, the barrier member is not coupled to the frame. In an example embodiment, the barrier member is coupled to the frame at perforations provided in the barrier member for the inlet, the outlet and/or a port, as described.

In an example embodiment, the restrictor is arranged proximal the lower wall portion of the frame or base of the tank, as described above. In this way, a residual portion of accumulated fluid in the volume may be reduced. In an example embodiment, the restrictor is arranged spaced apart from the lower wall portion of the frame or base of the tank, as described above. For example, the restrictor may be spaced less than 5 mm, less than 10 mm, less than 15 mm, less than 20 mm, less than 25 mm, less than 30 mm, less than 40 mm or less than 50 mm apart from the lower wall portion of the frame or base of the tank. In this way, a lower portion of the volume may provide a sump, in use. For example, solids such as suspended solids and/or debris may be deposited in the sump, in use. In this way, such solids are isolated from a drainage system since they may be retained in the tank. Particularly, the restrictor may be arranged spaced apart from the lower wall portion or base of the tank so as to reduce a residual portion of regulated fluid volume while a lower portion of the volume may provide a sump. In an example embodiment, the tank does not comprise a sump extending from the tank, for example outwardly from the tank. That is, the tank does not provide a conventional relatively deep sump, having a depth of 150 mm or 200 mm for example. Rather, the tank may provide a relatively shallow sump, having a depth in a range 5 to 50 mm, as described above with reference to spacing of the restrictor and the lower wall portion of the frame or base of the tank.

In an example embodiment, the restrictor comprises a flow control device.

In an example embodiment, the restrictor comprises a fixed restrictor, for example a passageway such as an aperture or orifice in a plate (i.e. an orifice plate) or a tube. In an example embodiment, the restrictor comprises a plurality of such fixed restrictors. A size and/or an effective size of the fixed restrictor may be determined, for example predetermined or calculated, to restrict the flow of the fluid through the outlet to a desired or required flow. For example, the size and/or the effective size of the fixed restrictor may be calculated according to a pressure due to the fluid received in the volume. For example, the size and/or the effective size of the fixed restrictor may be calculated according a head or a maximum head of water received in the volume. In an example embodiment, the restrictor comprises an orifice plate, wherein the plate is arranged to extend across the outlet. In an example embodiment, the orifice is arranged proximal the lower wall portion or base of the tank. For example, the orifice may be spaced less than 5 mm, less than 10 mm, less than 15 mm, less than 20 mm, less than 25 mm, less than 30 mm, less than 40 mm or less than 50 mm apart from the lower wall portion of the frame or base of the tank. The orifice may comprise a circular orifice, for example, having a diameter less than 4 mm, less than 6 mm, less than 8 mm, less than 10 mm, less than 12 mm, less than 15 mm, less than 20 mm or less than 30 mm. Alternatively, the orifice may comprise a noncircular orifice, such as a square or rectangular orifice.

In an example embodiment, the restrictor comprises a replaceable restrictor. In this way, a restrictor may be replaced with another restrictor, for example, having a different size and/or effective size.

In an example embodiment, the restrictor comprises a selectable restrictor. In this way, a restrictor may be selected having a required size and/or effective size.

In an example embodiment, the restrictor comprises a variable restrictor. In this way, a size and/or an effective size of the restrictor may be varied, for example according to a head of water received in the volume.

In an example embodiment, the restrictor is coupled to the outlet.

In an example embodiment, the tank comprises a port, for example an access port. The port may be arranged in an upper portion of the tank, for example through an upper wall portion of the frame and/or through the barrier member. The barrier member may comprise another passageway, through which the port extends. In this way, access to the volume in the tank may be provided, for example for inspection and/or maintenance. For example, solids as described previously may be removed from the tank. The port may comprise a cover, arranged to close or seal the port. The port may comprise a turret or riser, arranged to extend outwardly from the tank. For example, the turret may extend upwardly from the tank in use. The turret may extend more than 0.3 m, more than 0.4 m, more than 0.5m, more than 0.6 m outwardly from the tank. In this way, a distal end of the turret may coincide with a ground level, in use. The turret may be coupled to the frame, for example, mechanically coupled or adhesively coupled. The barrier member may be coupled to the turret, for example sealed or adhesively sealed around the turret. The turret may extend inwardly into the tank. The port may be arranged proximal the restrictor. For example, the restrictor may be arranged proximal a lower wall portion of the frame and the port may be arranged proximal an upper wall portion of the frame. In this way, access to restrictor in the tank may be provided, for example for inspection and/or maintenance.

In an example embodiment, the tank comprises a lifting point, for example a lifting eye, a fork pocket or a strap. The lifting point may be coupled to the tank, for example the lifting point may be coupled to the frame. In an example embodiment, the tank comprises a plurality of such lifting points. In this way, handling the tank may be facilitated and/or damage during handling tank, for example during installation, may be reduced.

In an example embodiment, the inlet comprises a pipe. For example, the inlet may comprise a pipe or a spigot having a standard diameter such as 110 mm or 160 mm. In an example embodiment, the inlet comprises a coupling member. For example, the inlet may comprise a male coupling member or a female coupling member, suitable for to be received or to receive respectively a mating coupling member of a pipe having a standard diameter such as 110 mm or 160 mm. In an example embodiment, the coupling member is formed in or with the frame and/or subframe, for example, integrally formed in or with the frame and/or subframe.

In an example embodiment, the barrier member is coupled to the inlet. For example, barrier member may be mechanically coupled or adhesively coupled to or around the inlet. In this way, leakage around the inlet may be reduced.

In an example embodiment, the outlet comprises a pipe. For example, the outlet may comprise a pipe having a standard diameter such as 110 mm or 160 mm. In an example embodiment, the outlet comprises a coupling member. For example, the outlet may comprise a male coupling member or a female coupling member, suitable for to be received or to receive respectively a mating coupling member of a pipe having a standard diameter such as 110 mm or 160 mm. In an example embodiment, the coupling member is formed in or with the frame and/or subframe, for example, integrally formed in or with the frame and/or subframe.

In an example embodiment, the barrier member is coupled to the outlet. For example, barrier member may be mechanically coupled or adhesively coupled to or around the outlet. In this way, leakage around the outlet may be reduced.

In an example embodiment, the tank comprises an elbow arranged to divert the outlet. In an example embodiment, the outlet comprises such an elbow. In this way, surface water may be harvested for subsequent use, by pumping accumulated surface water from the tank via the outlet, for example.

In an example embodiment, the tank comprises an isolator, for example an isolation or shutoff valve. The isolator may be arranged to isolate the outlet. In this way, fluid received in the volume may be stored or retained or held, for example. In this way, surface water may be harvested for subsequent use.

In an example embodiment, the tank comprises a secondary outlet. The secondary outlet may be arranged to permit discharge of the fluid received in the volume. For example, harvested surface water may be used subsequently.

In an example embodiment, the tank comprises a baffle, arranged within the volume defined by the barrier member, for example a geotextile baffle. In this way, fluid received in the volume may be stilled or treated, for example.

In an example embodiment, the tank comprises a water treatment device. In an example embodiment, the tank comprises a weir. In an example embodiment, the tank comprises an interceptor. In an example embodiment, the tank comprises a filter. The filter may be a perforated tube comprising the first or the second polymeric composition, as described above, having perforations in a range 1 to 10 mm, for example 5 mm. In this way, solids or liquids such as oils may be trapped in the tank, for example. The weir, the interceptor and/or the filter may be arranged proximal the restrictor.

The second aspect of the invention provides a kit of parts for a tank for subterranean use, the kit of parts comprising: a frame and a barrier member;

The kit may be as described herein with respect to the tank.

The third aspect of the invention provides a tank assembly, comprising a tank and a filter box, the tank comprising a frame and a barrier member;

wherein the frame is arranged to support the barrier member and the barrier member is arranged to define a volume to receive a fluid, in use; wherein the tank comprises an inlet and an outlet; and wherein the tank comprises a restrictor arranged to restrict, in use, a flow of the fluid through the outlet; and wherein the filter box is coupleable to the inlet.

The tank assembly may be as described herein with respect to the tank assembly, the tank and/or the filter box.

In an example embodiment, the filter box comprises a container, having an outlet coupleable to the tank. The filter box may comprise an open end. The filter box may comprise a filter cover arrangeable in or on the open end of the container. The outlet may comprise a 110 mm or a 160 mm or a standard size diameter tube coupled to the container and extending outwardly from a side wall portion of the container. The outlet may be spaced apart from a closed end of the container by less than 50 mm, less than 100 mm, less than 150 mm, less than 200 mm, less than 250 mm, less than 300 mm. In this way, a lower portion of the container may provide a sump, in use. In this way, source control of micro catchments may be provided.

The fourth aspect of the invention provides a method of manufacturing a tank for subterranean use, the method comprising:

providing a frame and a barrier member;

The method may comprise any of the steps described herein with respect to the tank.

For example, the method may include forming passageways in the barrier member. The method may comprise sealing the barrier member around the tank, for example, around the inlet and/or the outlet. The frame may comprise a plurality of subframes and the method may comprise assembling the subframes. The method may comprise coupling the subframes. The tank may comprise a port and the method may comprise providing the port. The port may comprise an access turret and the method may comprise providing the access turret.

The fifth aspect of the invention provides a method of installing a tank for subterranean use, the tank comprising a frame and a barrier member;

the method comprising:

coupling the outlet directly to a drainage system.

The method may comprise any of the steps described herein with respect to the tank assembly, the tank and/or the filter box.

For example, the method may comprise forming an excavation. The method may comprise handling the tank using lifting points of the tank. The method may include placing the tank in the excavation using the lifting points of the tank. The method may comprise coupling the inlet to a surface water source, such as the filter box. The method may comprise backfilling the excavation over the tank, including the lifting points.

Brief description of the drawings

For a better understanding of the invention, and to show how exemplary embodiments of the same may be brought into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which:

Figure 1 schematically depicts a cross-section of a tank according to an exemplary embodiment of the invention;

Figure 2 schematically depicts an isometric view of the tank of Figure 1;

Figure 3 schematically depicts a plan view of the tank of Figure 1;

Figure 4 schematically depicts a side elevation view of the tank of Figure 1;

Figure 5 schematically depicts a front elevation view of the tank of Figure 1;

Figure 6 schematically depicts a cross-section of a detail of the tank of Figure 1;

Figure 7 schematically depicts an isometric view of a frame of the tank of Figure 1;

Figure 8 schematically depicts an isometric view of a filter box of a tank assembly according to an exemplary embodiment of the invention;

Figure 9 schematically depicts a cross-section of the filter box of Figure 8, in use;

Figure 10 schematically an isometric view of the tank of Figure 1 and the filter box of Figure 8, in use;

Figure 11 schematically depicts a method of manufacturing a tank according to an exemplary embodiment of the invention;

Figure 12 schematically depicts a method of installing a tank according to an exemplary embodiment of the invention; and

Figure 13 schematically depicts a cross-section of the tank of Figure 1.

Detailed Description of the Drawings

Figures 1 - 5 schematically depict a tank 10 according to an exemplary embodiment of the invention. The tank 10 comprises a frame 20 and a barrier member 30. The frame 20 is arranged to support the barrier member 30 and the barrier member 30 is arranged to define a volume V to receive a fluid F, in use. The tank 10 comprises three inlets 40 and an outlet 50. The tank comprises a restrictor 60 arranged to restrict, in use, a flow of the fluid F (not shown) through the outlet 50. In this way, attenuation of surface water discharged into drainage systems may be improved.

Particularly, installation of the tank may be simplified compared with conventional installations because the restrictor 60 is arranged in the tank 10. In this way, additional excavation required for a conventional restrictor downstream of a conventional tank is avoided, for example, reducing complexity and/or cost of parts and/or installation. Further, couplings such as pipes required between conventional tanks and conventional restrictors are also eliminated, further reducing complexity and/or cost of parts and/or installation and improving reliability. In this way, the tank 10 may be more efficiently installed at both existing and new properties and/or curtilages. Furthermore, the tank 10 does not comprise a sump extending from the tank 10, for example outwardly from the tank 10, thereby reducing also an excavation depth. In addition, by providing the frame 20 to support the barrier member 30, tanks having different volumes may be more readily manufactured, as required.

In detail, the tank 10 has a general cuboidal form having dimensions 400 mm x 2000 mm x 2000 mm (height x length x width), arranged to receive about 1.5 m³ of surface water, as described above.

The frame 20 comprises a first or lower wall portion 21, a second or upper wall portion 22 opposed to the lower wall portion 21 and two pairs of opposed side wall portions 23A - 23D, arranged extending between the lower wall portion 21 and the upper wall portion 22, between edges of the lower wall portion 21 and the upper wall portion 22, and wherein adjacent wall portions 21,22, 23 are arranged mutually orthogonally. The wall portions 21,22, 23 are planar. The frame 20 comprises a plurality of internal ties and struts (not shown). The frame 20 comprises a plurality of passageways (not shown) such that the fluid may communicate, for example flow or freely flow, through the frame, in use.

The frame 20 comprises 8 cuboidal subframes 25 (detail not shown for clarity), arranged in an assembly of adjacent subframes 25 in a 1 x 2 x 4 (height x length x width) planar array, wherein the assembly defines the frame 20, as described above. Adjacent subframes 25 are coupled mechanically, using interlocks provided by the subframes 25, as described above. The subframes 25 are Permavoid (RTM) HD sub-base replacement modules, as described in more detail below with reference to Figure 7.

The barrier member 30 comprises an impermeable polypropylene (PP) geomembrane, having a thickness of 1.0 mm, as described above. The barrier member 30 is arranged externally with respect to the frame 20, encapsulating the frame 20. The barrier member 30 is fully sealed, as described above, defining the volume V to receive the fluid F.

The inlet 40 comprises a perforation (not shown) in the barrier member 30 aligned with a 110 mm diameter tube 45 coupled to the frame 20 and extending outwardly from an invert level of the side wall portion 23 of the tank 10, as described above. The tube 45 provides a male coupling member, as described above. The barrier member 30 is sealed around the tube 45, as described above.

The outlet 50 comprises a perforation (not shown) in the barrier member 30 aligned with a 110 mm diameter tube 55 coupled to the frame 20 and extending outwardly from an invert level of the side wall portion 23 of the tank 10, as described above. The barrier member 30 is sealed around the tube 55, as described above. The tube 55 also extends inwardly into the volume V, as described above.

The restrictor 60 is coupled to the internal end of the tube 55 using a push-fit female coupling member, as described above. The restrictor 60 comprises an orifice plate 65, having an orifice 67, as described in more detail with reference to Figure 6 below.

The tank 10 also comprises an access port 70 having an access turret 75, closeable with a cover 77, and coupled to the frame 20. The port 70 has a diameter of 600 mm. The access turret 75 extends outwardly from the upper wall portion 22 of the tank, opposed to the restrictor 60. The access turret 75 also extends inwardly to a lower wall portion of the tank 10, such that the restrictor 60 is arranged in the access turret 75. In this way, access to the volume V in the tank 10 may be provided, for example for inspection and/or maintenance. For example, solids as described previously may be removed from the tank. In this way, access to restrictor 60 in the tank 10 may be provided, for example for inspection and/or maintenance.

The tank 10 further comprises four fabric lifting straps 80, coupled to the tank 10, as described above. In this way, handling the tank 10 may be facilitated and/or damage during handling tank 10, for example during installation, may be reduced.

Figure 6 schematically depicts the tank 10 in more detail. As described above, the restrictor 60 is coupled to the internal end of the tube 55 using the push-fit female coupling member. The restrictor 60 comprises the orifice plate 65, having the orifice 67. The orifice 67 is a circular passageway in the orifice plate 65, the orifice 67 having a diameter of 11 mm. In this way, restrictor 60 may restrict, in use, the flow of the fluid F through the outlet 50 to around 0.2 dm³s¹. Other orifices 67 may be provided such that the restrictor 60 may restrict, in use, the flow of the fluid F through the outlet 50 to around 0.4dm³s¹, 0.6dm³s¹, less than 0.2 dm³s¹ or more than 0.6 dm³s¹, for example. The orifice 67 is arranged proximal the lower wall portion of the tank 10, spaced apart from the lower wall portion of the tank 10 by about 20 mm. In this way, a lower portion of the volume V may provide a sump, in use. For example, solids such as suspended solids and/or debris may be deposited in the sump, in use. In this way, such solids are isolated from a drainage system since they may be retained in the tank

10.

Figure 7 schematically depicts an isometric view of the subframe 25, which is a Permavoid (RTM) HD sub-base replacement modules. The frame 25 comprises a first or lower wall portion 26, a second or upper wall portion 27 opposed to the lower wall portion 26 and two pairs of opposed side wall portions 28A - 28D, arranged extending between the lower wall portion 26 and the upper wall portion 27, between edges of the lower wall portion 26 and the upper wall portion 27, and wherein adjacent wall portions 26, 27, 28 are arranged mutually orthogonally. The wall portions 26, 27, 28 are planar. The subframe 25 comprises a plurality of internal ties and struts (not shown). The subframe 25 comprises a plurality of passageways (not shown) such that the fluid may communicate, for example flow or freely flow, through the subframe 25, in use. These passageways are interconnected between adjacent subframes 25. In this way, the fluid may communicate, for example flow or freely flow, between adjacent subframes 25 in an assembly of subframes 25 as described above, in use.

The subframe 25 is a geo-cellular unit moulded from polypropylene (PP) and having a load bearing capacity of 700 kPa. The subframe 25 has a volumetric void of 92% and an effective perforated surface area of 59%.

Figure 8 schematically depicts an isometric view of a filter box 100 of a tank assembly 1, comprising the tank 10 and the filter box 100.

In detail, the filter box 100 comprises a cuboidal open container 110, having an outlet 150 and a filter cover 190, arrangeable in the open end of the container 110. The filter cover 190 comprises a grid, to allow passage of water and to retain debris. The outlet 150 comprises a 110 mm diameter tube 55 coupled to the container 110 and extending outwardly from a side wall portion of the container 10, similar to as described above with reference to the outlet 50. The outlet 150 is coupleable to the inlet 40 of the tank 10. In contrast to the outlet 50, the outlet 150 is spaced apart from a closed end of the container 100 by about 150 mm. In this way, a lower portion of the container 150 may provide a sump, in use.

Figure 9 schematically depicts a cross-section of the filter box 100, in use, arranged in the ground G beneath a downpipe D and coupled by a pipe (not shown) to the tank 10, as described above. Surface water discharged from the downpipe is received in the container 110 and subsequently flows towards the tank 10. Solids such as suspended solids and/or debris are deposited in the sump of the filter box 100. In this way, such solids are better isolated from the tank 10 since they may be retained in the container 110.

Figure 10 schematically an isometric view of the tank 10 and the filter box 100 of the tank assembly 1, in use. Particularly, the tank 10 is arranged under the ground G, having about 500 mm soil and/or aggregate arranged above the tank 10. Since the four fabric lifting straps 80 are coupled to the tank, the four fabric lifting straps 80 are also arranged in the ground G. Since the tank 10 has a relatively low height, as described previously, excavation is relatively shallow and the tank may be coupled to relatively shallow drainage systems. Since the restrictor 60 is provided in the tank 10, excavation sites and installation complexity are reduced, as described previously. The inlets 40 of the tank 10 are coupled to the outlets 50 of three filter boxes 100, arranged beneath downpipes D, as described previously. The outlet 50 of the tank 50 is coupled directly to a drainage system. The tank 50 is upstream of the drainage system DS. The inlets 40 are arranged upstream of the tank 50. The access turret 75 of the access port 70 protrudes through the surface of the ground G, allowing access to the volume V and the restrictor 60 of the tank, for maintenance, for example.

Surface water discharged from the downpipe is received in the filter boxes 100 and subsequently flows towards the tank 10. Solids such as debris, leaves, feathers, moss may be retained by the filter covers of the filter boxes 100. Solids such as suspended solids and/or debris may be deposited in the sumps of the filter boxes 100. In this way, source control of micro catchments may be provided. In this way, such solids are better isolated from the tank 10 since they may be retained in the containers 110. In this way, even if one filter box 100 blocks, for example, the installation would not fail as the other downpipes would still function and the water would fall freely from the roof - even at the blocked filter box 100. This is not the case with blockages encountered in traditional drainage systems

The surface water is subsequently received in the volume V of the tank. Discharge of the surface water through the outlet 50 is restricted by the restrictor 60 to around 0.2dm³s¹, thereby meeting permitted discharge rates into the drainage system DS. If the flow of surface water into the tank 50 exceeds this restricted discharge flow rate, the surface water accumulates in the volume V. When the flow of surface water into the tank 50 is less than this restricted discharge flow rate, the accumulated surface water is discharged, as determined by the restrictor 60. Further, solids such as suspended solids and/or debris may be deposited in the sump of the tank 10. Such solids may be removed through the access port 70. In this way, such solids are isolated from a drainage system since they may be retained in the tank 10.

Figure 11 schematically depicts a method of manufacturing a tank of the type described.

At S111 a frame and a barrier member are provided. At S112, the barrier member is supported by the frame, wherein the barrier member is arranged to define a volume to receive a fluid, in use. At S113, an inlet and an outlet are provided. At S114, a restrictor is provided, wherein the restrictor is arranged to restrict, in use, a flow of the fluid through the outlet.

The method may include any other steps described herein.

Figure 12 schematically depicts a method of installing a tank of the type described.

At S121, the outlet of the tank is coupled directly to a drainage system.

The method may include any other steps described herein.

Figure 13 schematically depicts a cross-section of the tank of Figure 1. In detail, the tank 10 further comprises two elbows 57 coupled to the outlet pipe 55 of the outlet 50. In this way, fluid accumulated in the volume V of the tank may be pumped from the tank for subsequent use. For example, surface water harvested in the tank 10 may be recycled.

Although a preferred embodiment has been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims and as described above.

In summary, the invention provides a tank for subterranean installation. The tank includes a frame and a barrier member. The frame is arranged to support the barrier member. The barrier member is arranged to define a volume to receive a fluid, in use. The tank has an inlet and an outlet. The tank further includes a restrictor arranged to restrict, in use, a flow of the fluid through the outlet. In this way, for example, a flow of surface water discharged from a property into a drainage system may be attenuated.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A tank for subterranean installation, the tank comprising a frame and a barrier member; wherein the frame is arranged to support the barrier member and the barrier member is arranged to define a volume to receive a fluid, in use;

wherein the tank comprises an inlet and an outlet; and wherein the tank comprises a restrictor arranged to restrict, in use, a flow of the fluid through the outlet.

2. A tank according to claim 2, wherein the barrier member is arranged externally with respect to the frame.

3. A tank according to any previous claim, wherein the frame comprises a plurality of subframes.

4. A tank according to any previous claim, wherein the frame comprises a first polymeric composition comprising a first thermoplastic polymer.

5. A tank according to any previous claim, wherein the barrier member comprises an impermeable barrier member.

6. A tank according to any previous claim, wherein the barrier member comprises a permeable barrier member.

7. A tank according to any previous claim, wherein the barrier member comprises a second polymeric composition comprising a second thermoplastic polymer.

8. A tank according to any previous claim, wherein the inlet is arranged at an invert level of the tank and the outlet is arranged at the invert level of the tank.

9. A tank according to any previous claim, wherein the restrictor is coupled to the outlet.

10. A tank according to any previous claim, wherein the restrictor comprises a fixed restrictor.

11. A tank according to any previous claim, wherein the tank comprises a port.

12. A tank according to any previous claim, wherein

13. A tank according to any previous claim, the tank comprises a water treatment device.

14. A tank according to any previous claim, wherein the tank comprises a filter.

15. A tank according to any previous claim, wherein the tank comprises a lifting point.

16. A method of manufacturing a tank for subterranean use, the method comprising: providing a frame and a barrier member;

supporting the barrier member by the frame, wherein the barrier member is arranged to define 35 a volume to receive a fluid, in use;

providing an inlet and an outlet, wherein the outlet is coupleable directly to a drainage system; and providing restrictor arranged to restrict, in use, a flow of the fluid through the outlet; wherein the restrictor is arranged in the tank;

wherein the restrictor is coupled to the outlet; and wherein the restrictor comprises an orifice plate, wherein the plate is arranged to extend across the outlet.

5

17. A method of installing a tank for subterranean use, the tank comprising a frame and a barrier member;

wherein the tank comprises an inlet and an outlet, wherein the outlet is coupleable directly to a

10 drainage system; and wherein the tank comprises a restrictor arranged to restrict, in use, a flow of the fluid through the outlet;

wherein the restrictor is arranged in the tank; wherein the restrictor is coupled to the outlet; and

15 wherein the restrictor comprises an orifice plate, wherein the plate is arranged to extend across the outlet, the method comprising:

coupling the outlet directly to a drainage system.

02 10 17

Intellectual

Property

Office

Application No: GB1611443.1 Examiner: Dr Fabio Noviello

16. A kit of parts for a tank for subterranean use, the kit of parts comprising:

a frame and a barrier member;

17. A tank assembly, comprising a tank and a filter box, the tank comprising a frame and a barrier member;

18. A method of manufacturing a tank for subterranean use, the method comprising: providing a frame and a barrier member;

19. A method of installing a tank for subterranean use, the tank comprising a frame and a barrier member;

the method comprising:

coupling the outlet directly to a drainage system.

20. A tank, a kit of parts for a tank, a tank assembly, a method of manufacturing a tank and/or a method of installing a tank substantially as described herein and with reference to and as shown in the accompanying Figures.

Amendments to the claims have been filed as follows:

02 10 17

1. A tank for subterranean installation, the tank comprising a frame and a barrier member; wherein the frame is arranged to support the barrier member and the barrier member is

5 arranged to define a volume to receive a fluid, in use;

wherein the tank comprises an inlet and an outlet, wherein the outlet is coupleable directly to a drainage system;

wherein the tank comprises a restrictor arranged to restrict, in use, a flow of the fluid through the outlet;

10 wherein the restrictor is arranged in the tank;

15 2. A tank according to claim 1, wherein the barrier member is arranged externally with respect to the frame.

5. A tank according to any previous claim, wherein the barrier member comprises an

25 impermeable barrier member.

30 7. A tank according to any previous claim, wherein the barrier member comprises a second polymeric composition comprising a second thermoplastic polymer.

9. A tank according to any previous claim, wherein the restrictor comprises a fixed restrictor.

10. A tank according to any previous claim, wherein the tank comprises a port.

11. A tank according to any previous claim, the tank comprises a water treatment device.

12. A tank according to any previous claim, wherein the tank comprises a filter.

5 13. A tank according to any previous claim, wherein the tank comprises a lifting point.

14. A kit of parts for a tank for subterranean use, the kit of parts comprising: a frame and a barrier member;

wherein the frame is arranged to support the barrier member and the barrier member is 10 arranged to define a volume to receive a fluid, in use;

an inlet and an outlet, wherein the outlet is coupleable directly to a drainage system; and a restrictor arranged to restrict, in use, a flow of the fluid through the outlet; wherein the restrictor is arranged in the tank;

wherein the restrictor is coupled to the outlet; and

15 wherein the restrictor comprises an orifice plate, wherein the plate is arranged to extend across the outlet.

15. A tank assembly, comprising a tank for subterranean use and a filter box, the tank comprising a frame and a barrier member;

20 wherein the frame is arranged to support the barrier member and the barrier member is arranged to define a volume to receive a fluid, in use;

wherein the tank comprises an inlet and an outlet, wherein the outlet is coupleable directly to a drainage system; and wherein the tank comprises a restrictor arranged to restrict, in use, a flow of the fluid through 25 the outlet;

wherein the restrictor is arranged in the tank; wherein the restrictor is coupled to the outlet; and wherein the restrictor comprises an orifice plate, wherein the plate is arranged to extend across the outlet; and

30 wherein the filter box is coupleable to the inlet.