The present invention relates to sumps. It is particularly applicable, but in no way limited to sumps for use beneath fuel dispensing pumps. Such sumps are generally located below ground level and are designed to keep ground water out and to prevent any fuel drippage or leakage from entering the environment.
In a typical automotive fuelling station, fuel is delivered to an above-ground dispensing pump through a network of underground tanks, pipes, fittings, sumps and dispensers. The sumps used in these networks include sumps located beneath the above-ground dispensing units. These sumps preferably fit fully beneath the housings for the above-ground dispensing units and function to prevent ground contamination from any drippage of components in the above-ground dispensing units.
In order to reduce the risk of soil contamination, it is desirable, if not imperative, for sumps located beneath the above-ground dispensing units to receive any and all fuel that may leak or drip from the dispensing units. For this reason, the openings of such sumps are large enough to completely cover the potential drip area beneath the dispensing units. It also is economically desirable to avoid making the sumps too large.
Thus, it is common to have properly designed sumps with openings that are sized and shaped to match the footprint of the dispensing unit housing, ie the size and shape of the opening of the sump are sized and shaped to correspond to the area where drippage may occur.
In a typical installation the sumps are made from a plastics material such as a polymer eg polyethylene or polypropylene, or from a resin such as glass or fibre reinforced plastic (GRP/FRP). The dispensing unit is connected to the sump by way of a mounting frame which itself is bolted to the sump. This inevitably involves drilling or forming holes in the side walls of the sump. These perforations in the body of the sump have to be sealed to avoid ingress of ground water and any egress of fuel or fuel vapour into the surrounding ground. In practice sealing these penetrations, and retaining those seals over many years proves difficult and requires regular checks and maintenance as necessary.
A further problem with current sumps is the fact that they are inevitably provided with opposing channels to accommodate unistruts, which in turn support stabiliser bars designed to hold the fuel supply pipes and associated safety connectors. These channels extend inwardly across the top opening of the sump and partially block access to the sump contents.
As explained above, containment sumps are known. An example of a prior art sump is illustrated in U.S. Pat. No. 5,800,143 (Bravo). This illustrates an arrangement where an anchor frame is attached to the top of a sump, with a dispenser frame being attached to the anchor frame. This results in numerous penetrations through the upper region of the sump, with all the disadvantages of potential water ingress/fuel egress described above. It also clearly serves to illustrate how fixing rails (27) restrict the sump opening.
U.S. Pat. No. 5,099,894 (Mozeley) describes a fibreglass sump with an outwardly extending flange but, as with other prior art, fixings which penetrate through the sump walls are required to connect the dispenser to the sump, in this case through an intermediate shear box. This arrangement has all the disadvantages outlined above.
WO99/16978 (Mangum) describes a two-part sump having a lower, rectangular portion and a separate tapered upper portion. The two portions are sealed together on site during construction. Once again, the unistrut rails encroach on the sump opening and there are penetrations through the sump body below ground level.
U.S. Pat. No. 5,257,652 (Total Containment Inc) describes a sump with a riser where a separate flanged portion is bolted through the sump riser near its top. The bolt holes provide a route for water ingress/fuel egress.
A further typical prior art sump with a so-called unitary sump frame is illustrated in U.S. Pat. No. 5,813,797 (Pendleton & Matracia). Once again, this has all the disadvantages outlined above.
It is an object of the present invention to overcome or at least mitigate one or more of these problems.
According to a first aspect of the present invention there is provided a sump assembly according to claim 1. Preferably said sump assembly comprises:—
By providing a flange integral with the sump side wall(s) it is no longer necessary to perforate the sump to attach a separate frame or flange. Thus the sump body remains imperforated.
Preferably the sump body incorporates a retaining rib at or near the opening, said rib being adapted to retain the mounting frame assembly without the need to form penetrations in the side wall(s).
The retaining rib is just one form of mounting frame retaining means which could be used to retain the mounting frame assembly in place during construction.
Preferably the sump body further comprises a channel, said channel being adapted to accommodate a strut mounting assembly such that said strut mounting assembly does not extend substantially into the opening in the top of the sump body and thus does not restrict access to the sump body.
By providing the sump assembly with an integral flange, this provides a location for this channel, away from sump opening, but directly adjacent to that opening, giving unrestricted access to the sump opening when the unistruct mounting channel is in place.
Preferably the flange fixing means comprises apertures or eyelets in the flange designed to be embedded in concrete. These are inexpensive to manufacture and effective in use.
Preferably the mounting frame assembly comprises a mounting plate, and preferably said mounting plate incorporates dependent lugs adapted to tie the plate into the surrounding concrete.
Preferably said mounting plate incorporates conduit entry holes. These entry holes allow cables and other items safe and effective entry into the sump body and thus dispensing units.
Preferably said mounting frame assembly further comprises a mounting frame adapted to secure a dispensing unit to the sump assembly.
Preferably said mounting frame incorporates apertures for anchor bolts to anchor a dispenser unit to the sump assembly.
The present invention will now be described by way of example only with reference to the accompanying drawings, wherein:—
The present embodiments represent currently the best ways known to the applicant of putting the invention into practice. But they are not the only ways in which this can be achieved. They are illustrated, and they will now be described, by way of example only. By way of terminology used in this document the following definitions apply:—
Sump/Containment chamber—any receptacle designed to keep a fluid in or out. This includes, but is not limited to, access manhole and sump chambers as described herein. It also includes tanks in general.
Flange—any collar or extension suitable for providing anchorage of a sump assembly into the surrounding ground, usually into concrete. The flange may be augmented by J-bolts or other fixings. Where the flange is described as an “integral” flange, this is intended to encompass arrangements where the flange is formed with the sump during the sump construction process, for example by injection or rotomoulding. It is also intended to encompass arrangements where the sump and flange are initially formed separately and joined together to form a unitary construction during manufacture.
Fluid—whilst the examples provided relate mainly to liquids, the term fluid refers to liquids, vapours and gases. For example, should a leak occur in a secondarily contained pipe in a garage forecourt installation then petrol or petrol vapour will collect in the manhole chamber. It is essential that this petrol vapour cannot escape through the wall of the chamber and into the surrounding ground.
Pipe—where pipes are referred to herein they are generally of circular cross-section. However, the term also covers other cross-sections such as box sections, corrugated and the like and secondarily contained pipes of the “pipe-within-a-pipe” type.
Glass reinforced plastic (GRP)—The term GRP has a very broad meaning in this context. It is intended to encompass any fibre-reinforced plastic wherein a fibre of any type is used to strengthen a thermosetting resin or other plastics material.
Plastics Material—The term has a very broad meaning in this context and is intended to encompass any polymeric material including thermoplastics, thermosets, elastomeric or any other polymeric material.
Referring now to the drawings, and to
A typical prior art sump assembly 50 is shown in more detail in
Turning now to
It will be understood that the flange in this invention can take on a wide variety of shapes, sizes and locations. Its purpose is to act as an anchoring means to anchor the sump assembly when it is installed below ground. For example, the flange could take the form of a plurality of extending and depending arms extending away from the body of the sump around the opening. It is not necessary to limit the presence of a flange to the longer side walls of the sump body but there could be some form of anchoring means on the shorter sump side walls. In addition or instead of the flanges shown in
It will be appreciated that in these examples the flange has a finite and significant thickness. Thus, each flange comprises an upper and lower surface with a flange body there between. The flange body is tapered in its thickness, being wider in the region where it meets the sump body. End or side walls enclose the remaining periphery of the flange, which may be hollow, partly hollow or a solid body. Preferably the flange body where it meets the sump body is large enough to accommodate a channel which enables the sump opening to be kept substantially free of obstructions in use (see below).
The incorporation of a flange extending substantially the width of each long side wall of the sump body brings with it a further advantage. This is illustrated in
A corresponding unistrut is inserted into a corresponding channel on the opposing side face of the sump body and, in combination, they provide support along with the appropriate cross members for the pipework and other fittings, including safety fittings, for the fuel supply lines leading up to and into the fuel dispenser unit. This arrangement is shown more clearly in the cross-sectional view shown in
This view emphasises how the offsetting of the channels 82 and thus the unistruts 83, away from the opening in the top of the sump, leads to a substantially clear and unrestricted opening of the sump, something which has never been possible in the past, shown in more detail in
A further component of the sump assembly is a mounting frame assembly. In this embodiment the mounting frame assembly takes the form of a mounting frame 90 which is adapted and used to locate anchor bolts for the dispenser unit. Typically this mounting frame is formed from sheet steel which may be galvanised, plated or painted in order to protect it from the elements. This mounting frame incorporates a series of functional features. Firstly, it incorporates downwardly depending lugs 91 for tying the mountain frame into the surrounding concrete. In this example, four downwardly depending lugs are shown but this number could be increased or decreased as necessary. Also incorporated are conduit entry holes 93, in this example three conduit entry holes being provided at each end of the sump opening. These conduit entry points allow for the installation of conduits, and associated draw wires as necessary, in order to feed electrical and other services into the dispenser unit. Also incorporated into the mounting frame 90 are holes for positioning anchor bolts which are designed to locate into and secure the dispensing unit to the sump assembly. Four such anchoring bolts, in the form of J-bolts are shown in
To further explain how the mounting frame is adapted to accommodate the base of the dispensing unit, a template for that dispensing unit base is shown as 99 in
A further feature of the current sump assembly is that a rib 94 is provided around part or substantially all of the upper section of the sump body near the opening 76 in the top of the sump. This rib is adapted to retain the mounting frame/flange in place during assembly. That is to say, the mounting frame is a tight snap fit over this rib and, once the necessary anchoring bolts have been assembled onto the mounting frame this is placed over the opening of the sump body and is tapped or otherwise forced over the rib 94. The rib extends around substantially the entire external circumference of the sump body. It is separate from the flange(s) and is located, of necessity, above the flange region. The rib is lined up, in use, with the intended ground level and the region surrounding the sump body is backfilled with concrete such that the mounting frame is level with the top of the concrete. A rain lip 97 is provided which manages any surface water which comes up to the sump body and prevents the sump from flooding.
This external snap fit is an important feature because it enables the mounting frame assembly to be attached to the sump body without making any penetrations or perforations through the sump walls. A substantially continuous rib extending around the external circumference of the sump opening is just one possible form of ‘snap fit’ arrangement. Many other forms of ‘snap fit’ arrangement are known, and may be applied in this application. For example, a series of lugs or shoulders could be formed on the outside of the sump body, adapted to engage with corresponding features on the mounting frame.
Also provided is a vacuum test lid (85) which, once held in place, means that it is possible to verify the integrity of the sump and its associated fittings by applying a vacuum to the sump assembly. This integrity can be tested both before and after installation of the sheer valves due to the height of the rain lip. That is to say, the rain lip stands sufficiently proud that it will accommodate any sheer valves installed within the sump body yet still allow the vacuum test lid to be put in place and a vacuum test to be carried out.
It will be appreciated that all of these embodiments have in common integral flanges which incorporate fixing means adapted to tie the sump into the surrounding groundworks. They also incorporate channels, set into the body of each flange, to accommodate unistruts. These unistruts are fixed in place without the need for any penetrations through the sump walls. They also include a mounting frame assembly which again is held in place without requiring fixings which penetrate the sump walls. There are thus no gaskets or seals used in the sump which can deteriorate over time and thus no expensive maintenance is required.
The sumps are of one piece, integral construction, free from any penetrations through the sump wall(s).
The various features described above, whilst all being shown together in a single example, can be used singly in a sump, or in any desired combination. They will work independently of each other.
With regards to constructional materials, the sump body is generally formed from a plastics material such as polyethylene or polypropylene since this material is electrofusible and electrofusion couplings can be used to form a fluid-tight seal between any incoming pipework and the sump body. Such electrofusion couplings are shown in
Number | Date | Country | Kind |
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0708850.3 | May 2007 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB08/01605 | 5/9/2008 | WO | 00 | 10/28/2009 |