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Title:
INLINE FLUID STRAINER INCLUDING A CROSS-FLOW CARTRIDGE
Document Type and Number:
WIPO Patent Application WO/2017/203461
Kind Code:
A1
Abstract:
This invention concerns an inline fluid strainer (10, 60, 70, 90, 100, 110, 120). The strainer (10, 60, 70, 90, 100, 110, 120) includes a body (12) comprising an inlet (14), an outlet (16) and a chamber (18) between the inlet (14) and outlet (16). A filtration element (42, 122) is connectable to the body (12) in a position wherein it is located inside the chamber such that, in use, the longitudinal axis of the filtration element (42, 42) is transverse to the flow direction through the inlet (14) and/or the flow direction through the outlet (16). The filtration element (42, 122) has a side wail (46) defining a substantially enclosed internal volume. The filtration element (42, 122) is located inside the chamber (18) so that the operating fluid is allowed to flow, in use, into the internal volume though a major portion of the surface area of the side wall (46).

Inventors:
BOOYENS, Andries Matthys (149 8th Avenue, Heatherdale Akasia, 0182 Pretoria, 0182, ZA)
Application Number:
IB2017/053084
Publication Date:
November 30, 2017
Filing Date:
May 25, 2017
Export Citation:
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Assignee:
BOOYENS, Andries Matthys (149 8th Avenue, Heatherdale Akasia, 0182 Pretoria, 0182, ZA)
International Classes:
B01D35/02; B01D29/15; B01D29/33; B01D29/60; B01D35/16; B03B7/00; E03B7/00
Foreign References:
US6187177B12001-02-13
CA754894A1967-03-21
CN201482291U2010-05-26
US4207181A1980-06-10
Other References:
None
Attorney, Agent or Firm:
SPOOR & FISHER et al. (11 Byls Bridge Boulevard, Building No. 14Highveld Ext 73, 0157 Centurion, 0157, ZA)
Download PDF:
Claims:
CLAIMS 1. An inline fluid strainer including:

a body comprising an inlet, an outlet and a chamber between the inlet and outlet;

a filtration element which is connectable to the body in a position wherein it is located inside the chamber such that, in use, the longitudinal axis of the filtration element is transverse to the flow direction through the inlet and/or the flow direction through the outlet; wherein the filtration element has a side wail defining a substantially enclosed internal volume, and wherein the filtration element is located inside the chamber so that the operating fluid is allowed to flow, in use, into the internal volume though a major portion of the surface area of the side wall. 2. An inline fluid strainer according to claim 1, wherein the filtration element is arranged so that the fluid flows around at least a major portion of the periphery of the filtration element. 3. An inline fluid strainer according to either claim 1 or 2, wherein the filtration element substantially seals off the outlet of the body, thereby, in use, forcing the flow of fluid into the filtration element prior to exiting the outlet. 4. An inline fluid strainer according to claim 3, wherein the filtration element engages the body at the outlet. 5. An inline fluid strainer according to either claim 3 or 4, including a locating formation for locating the filtration element inside the body. 6. An inline fluid strainer according to claim 5, wherein the locating formation is located on the filtration element.

7. An inline fluid strainer according to claim 6, wherein the locating formation is shaped to engage a complementally shaped locating formation carried by the body.

8. An inline fluid strainer according to claim 7, wherein the locating formation on the filtration element is in the form of a spigot-like protrusion extending from its side wall.

9. An inline fluid strainer according to claim 8, wherein the protrusion is shaped to engage an internal surface of the outlet of the housing such that the outlet forms the complementally shaped locating formation on the housing.

10. An inline fluid strainer according to any one of claims 1 to 9, wherein the filtration element is connectable to the body in a position wherein its longitudinal axis is substantially perpendicular to the flow direction into inlet and/or the flow direction out of the outlet.

11. An inline fluid strainer according to any one of claims 1 to 10, wherein the body carries slip ring flanges which allows for the installation of the strainer in a position wherein the longitudinal centreline of the body is angled relative to the vertical.

12. An inline fluid strainer according to any one of claim 1 to 11, wherein the inlet and outlet are offset relative to one another.

13. An inline fluid strainer according to claim 12, wherein the inlet and outlet are offset in two planes.

14. An inline fluid strainer according to any one of claims 1 to 14, wherein the filtration element is cylindrical.

15. An inline fluid strainer according to any one of claims 1 to 14, wherein the internal volume of the filtration element is substantially closed off by end walls located at longitudinally opposed ends of the side wall, wherein the side wall and/or at least one of the end walls are made from screening material such that fluid is filtered through the side wall and/or end walls as it enters the internal volume of the filtration element allowing.

16. An inline fluid strainer according to any one of claims 1 to 15, wherein the filtration element includes reinforcement ribbing to improve its strength and thereby resist deformation.

17. An inline fluid strainer according to any one of claims 1 to 16, wherein the filtration element is made from a section of sheet material which has two opposed edges that are welded to one another to create a cylindrically shaped filtration element.

18. An inline fluid strainer according to any one of claim 1 to 17, wherein the filtration element includes a T-piece having a stub end for connecting the T-piece to the outlet and two opposed ends to which sections of woven mesh-like perforated sheeting or any other screening material is connected.

19. An inline fluid strainer according to any one of claims 1 to 25, including a drainage or scour opening located in the body of the strainer.

20. An inline fluid strainer according to claim 19, including an intermediate section which is connected between the body of the fluid strainer and the drainage opening, wherein the intermediate section defines a neck formation, thereby reducing the size of the drainage opening.

Description:
INLINE FLUID STRAINER INCLUDING A CROSS-FLOW CARTRIDGE

BACKGROUND TO THE INVENTION

This invention relates to a fluid strainer. In particular, but not exclusively, the invention relates to an inline fluid strainer including a cylindrical filtration element which is perpendicular to the fluid flow stream.

An inline fluid strainer is typically installed in a water pipeline upstream of vulnerable equipment. The strainer serves to protect the vulnerable equipment from foreign particles entering the pipeline upstream of the strainer. Foreign particles often enter the pipeline where pressure bursts upstream of the strainer are experienced. It is generally found that, prior to repairing the burst pipe, particles such as pebbles, gravel and sand enter the pipeline and are fed to the vulnerable equipment located downstream of the burst location. Strainers therefore serve to remove the foreign particles from the fluid flow. A common problem currently being experienced is that water meter distributors use imported inline water strainers that are equipped with strainer cartridges or filters which are not suited for local conditions. This problem is particularly prevalent in a country such as South Africa where old asbestos cement pipeline pressure bursts often occur. These known imported cartridges are similar in design and operate on the common principle that detritus enters an open end of the cartridge which traps the majority of foreign particles larger than 3 - 5mm prior to discharging the filtered water from the inside of the cartridge to the outside. A drawback of this cartridge design is that the limited capacity of the cartridge rapidly fills up with detritus to the cartridge's maximum capacity, thereby causing the gradual development of a very high unbalanced pressure. This high, unbalanced pressure is known to cause the cartridge to explode, which causes an instantaneous high downstream flow velocity in the pipeline, thereby destroying the vulnerable equipment downstream of the strainer, such as control valves, water meters, isolating valves etc. Some water meter manufacturers utilise the cast iron bodies of their water meters to accommodate customised cartridges which fit inside the bodies. Another drawback of the available commercial strainers is their overall flange face to face length, especially when the cartridge size is increased. Yet another disadvantage of these known strainers is their dimensions do not suit other replacement strainers, especially when the replacement strainer cartridge size is increased, for greater strength, larger free flow area and less frictional pressure loss.

For the abovementioned reasons it is important that the strainer cartridges used in the inline water strainers have sufficient capacities and strength to mitigate the risk of catastrophic damage and, accordingly, of causing damage to vulnerable equipment downstream of the strainer.

The problems with clogging strainer cartridges are largely as a result of a limitation of the open surface area (free flow area) of the cartridge compared to the cross-sectional flow area of the water through the supply line, strainer or water flow meter, in which the cartridge is housed. This ratio is typically inversely proportional to the volume of water that can be filtered by the cartridge before it clogs up. It therefore follows naturally that this ratio should ideally be increased. As mentioned above, the clogging of the cartridges generally leads to a substantial increase in differential pressure across the strainer which, in turn, often results in malfunctioning control valves, especially reducing valves. Malfunctioning pressure reducing valves are often the cause of burst downstream pipes. The problem of malfunctioning pressure reducing valves is also aggravated in pipelines including older pipes such as asbestos cement (AC) pipes, resulting in burst pipes. It is often found that these older pipes have perished over time and, accordingly, include some areas of weakness which are particularly vulnerable to catastrophic failure, due to excessive pressure caused by malfunctioning automatic hydraulic pressure reducing control valves. It is therefore critical that the water pressure inside the pipeline is more accurately controlled by fully functional automatic pressure reducing valves in order to prevent catastrophic failure of these older pipes and even new pipes, such as UPVC and HDPE pipes.

Different solutions have been proposed in an attempt to increase the ratio of the open surface area of the cartridge to the cross-sectional flow area of the water, in particular in high volume flow rate applications. One known solution is to use a flat stainless steel woven mesh or perforated sheeting screen mounted vertically directly across the flow path. One problem of using the screen is that it tends to deform under the differential pressure of the fluid flow across the screen. This also applies to folded aizzag screens. This problem is exacerbated by increased water pressures as a result of progressive clogging of the screen in use. It has also been found that the screen vibrates, in use. The vibration causes the protective coating applied to the metal strainer shell or body to come off which, in turn, results in the body suffering extensive rust damage until it ultimately fails catastrophically.

Another strainer that has been proposed in high volume flow rate applications make use of a cylindrical cartridge that is mounted in a position in which its axial centreline is in line with the fluid flow through the strainer. Although this type of strainer improves the free flow area of the cartridge it has been found not to be commercially viable due to high manufacturing and maintenance costs. In this type of strainer the cartridge is mounted inside the strainer housing using additional mounts carried by the cartridge. The additional mounts not only increases complexity and costs but also takes up valuable space inside the housing. Another drawback of this type of strainer is that its housing has to be enlarged in order to allow for the insertion and removal of the cartridge. For these reasons the strainers using inline cartridges are unavoidable large.

Although another type of strainer, in which the cartridge is mounted at an angle of 30 to 60 degrees to the flow direction, has been suggested in an attempt to reduce the overall size of the strainer. A konwn problem with this strainer is that it makes use of an open inlet cylindrical basket type cartridge, which has a flow direction from the inside to the outside of the cartridge. The detritus is then collected inside the basket, thereby progressively reducing the free flow area of the cartridge, as it fills up with detritus. The free flow (open) area of these cartridges is also insufficient for long periods of operation. These cartridges are also prone to explosion, due to high unbalanced pressure conditions, and very small wall thickness.

Another problem with some of the known cartridges is that the catastrophic failures take place as a result of inferior build quality. This problem has in the past been addressed by simply increasing the robustness of the cartridge. One way of doing this is to increase the thickness of the stainless steel woven mesh or perforated plate of the cartridge and its supporting body. Although this solution might prevent failure of the cartridge it also increases production costs significantly, which naturally increases the sales price. Consequently, these robust cartridges are in many instances not installed due to their higher sales prices. The alternative, thicker stainless steel plate also limits the size of the smaller slotted or round perforations. The punch process used by most manufacturers to manufacture these screens is only able to punch hole sizes much larger than the plate thickness. Increasing the free flow open area of cartridges normally results in much larger overall dimensions of the strainer body or shell. it is an object of this invention to alleviate at least some of the problems experienced with existing inline water strainers and their cartridges.

It is a further object of this invention to provide an inline fluid strainer that will be a useful alternative to existing strainers, it is yet a further object of this invention to provide an inline fluid strainer that will be a useful alternative for replacement of existing strainers. It is thus an object of the invention to provide a strainer capable of being retrofitted so as to replace existing malfunctioning strainers.

SUMMARY OF THE INVENTION

En accordance with a first aspect of the invention there is provided an inline fluid strainer including:

a body comprising an inlet, an outlet and a chamber between the iniet and outlet;

a filtration element which is connectable to the body in a position wherein it is located inside the chamber such that, in use, the longitudinal axis of the filtration element is transverse to the flow direction through the inlet and/or the flow direction through the outlet;

wherein the filtration element has a side wall defining a substantially enclosed internal volume, and wherein the filtration element is located inside the chamber so that the operating fluid is allowed to flow, in use, into the internal volume though a major portion of the surface area of the side wall.

The filtration element is preferably arranged so that the fluid flows around at least a major portion of the periphery of the filtration element. Preferably, the filtration element substantially seals off the outlet of the body, thereby, in use, forcing the flow of fluid into the filtration element prior to exiting the outlet.

The filtration element may engage the body at the outlet.

The fluid strainer may include a locating formation for locating the filtration element inside the body. The locating formation is preferably located on the filtration element.

The locating formation may be shaped to engage a complementally shaped locating formation carried by the body. The locating formation on the filtration element may be in the form of a spigot-like protrusion extending from its side wall. The protrusion is preferably shaped to engage an internal surface of the outlet of the housing such that the outlet forms the complementally shaped locating formation on the housing.

In one embodiment the protrusion is substantially tubular.

The filtration element may be connectable to the body in a position wherein its longitudinal axis is substantially perpendicular to the flow direction into inlet and/or the flow direction out of the outlet.

The body may further carry slip ring flanges which allows for the installation of the strainer in a position wherein the longitudinal centreline of the body is angled relative to the vertical.

The inlet and outlet may be offset relative to one another. The inlet and outlet may be offset in two planes.

In one embodiment the filtration element is cylindrical.

The internal volume of the filtration element may be substantially closed off by end walls located at longitudinally opposed ends of the side wall, wherein the side wall and/or at least one of the end walls may be made from screening material such that fluid is filtered through the side wail and/or end walls as it enters the internal volume of the filtration element allowing.

The screening material may be woven, mesh-like perforated sheeting or wedge wire screen material.

The filtration element may include reinforcement ribbing to improve its strength and thereby resist deformation.

The fluid strainer may further include an access opening located in the body which is closable using a removable cap or lid so as to allow access to the filtration element located inside the body through the access opening when the cap is removed.

In one embodiment the filtration element is carried by the inspection cap so that the filtration element may be removed together with the inspection cap. The filtration element may be connected to the cap using fasteners, which act as securing means.

In another embodiment the filtration element may be separate or detached from the cap so that the cap and filtration element are independently removable from the body of the strainer.

The filtration element may be made from a section of sheet material which has two opposed edges that are welded to one another to create a cylindrically shaped filtration element.

The filtration element is preferably made from stainless steel.

In one embodiment the filtration element includes a T-piece having a stub end for connecting the T-piece to the outlet and two opposed ends to which sections of woven mesh-like perforated sheeting or any other screening material is connected. The fluid strainer may include a drainage or scour opening located in the body of the strainer.

The drainage opening may be closed off with a removable drainage lid, or an isolating or scour valve.

The fluid strainer may include an intermediate section which is connected between the body of the fluid strainer and the drainage opening. The intermediate section may have a neck formation, thereby reducing the size of the drainage opening. The intermediate section is preferably removably connectable to the body.

The fluid strainer may include pressure gauges for measuring the pressure at its inlet and outlet in order to determine the differential pressure across the strainer for consideration to decide on full maintenance or convenient and rapid scouring during its maintenance routine, by means of a manual or automatic differential pressure control valve.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows a cross-sectional side view of an inline fluid strainer in accordance with a first embodiment of the invention in which the flow direction is from left to right;

Figure 2 shows a cross-sectional view of the inline fluid strainer of

Figure 1 in pian;

Figure 3 shows a cross-sectional side view of an inline fluid strainer in accordance with a second embodiment of the invention; Figure 4 shows a cross-sectional side view of an inline fluid strainer in accordance with a third embodiment of the invention;

Figure 5 shows an end view of the inline fluid strainer of Figure 4 in which its enclosure is not shown for the sake of clarity;

Figure 6 shows a detailed cross-sectional view of a connection between a flange of the inline fluid strainer of Figure 4 and an adjoining pipe;

Figure 7 shows an end view of the inline fluid strainer of Figure 4 in which its filtration element chamber is angled relative to the vertical;

Figure 8 shows a cross-sectional side view of an inline fluid strainer in accordance with a fourth embodiment of the invention;

Figure 9 shows a cross-sectional side view of an inline fluid strainer in accordance with a fifth embodiment of the invention;

Figure 10 shows a cross-sectional side view of an inline fluid strainer in accordance with a sixth embodiment of the invention;

Figure 11 shows a cross-sectional view of the inline fluid strainer of

Figure 10 in plan; and

Figure 12 shows a cross-sectional side view of an inline fluid strainer in accordance with a seventh embodiment of the invention. DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms "connected," "engaged," and "secured" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings and are thus intended to include direct connections between two members without any other members interposed therebetween and indirect connections between members in which one or more other members are interposed therebetween. Further, "connected" are not restricted to physical or mechanical connections or couplings. Additionally, the words "vertical", "horizontal", "lower", "upper", "upward", "down" and "downward" designate directions in the drawings to which reference is made. The terminology includes the words specifically mentioned above, derivatives thereof, and words or similar import. It is noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the," and any singular use of any word, include plural referents unless expressly and unequivocally limited to one referent. As used herein, the term "include" and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.

Referring to the drawings, in which like numerals indicate like features, a non-limiting example of an inline fluid strainer in accordance with a first embodiment of the invention is generally indicated by reference numeral 10. The inline fluid strainer 10 is also referred to as an inline fluid filter. The inline fluid strainer 10 will be described as a water strainer in this description but it should be understood that the invention is not limited to this particular application. The fluid could be any suitable fluid other than water, such as petroleum, dairy etc. when manufactured from suitable materials.

The inline fluid strainer 10 has a body 12 which includes an inlet 14, an outlet 16 and a chamber 18 located between the inlet and outlet. In the accompanying drawings the fluid flow direction is indicated by the reference numeral 20.

The body 12 of the strainer 10 is substantially cylindrical in shape and has two ends 22.1 and 22.2, which are the two longitudinally opposed ends of the cylindrical body. It is envisaged that the strainer 10 will be mounted onto a pipeline (not shown in the accompanying drawings) in such a manner that the longitudinal centreline of the body 12 extends substantially vertically. By mounting the strainer 10 vertically the end 22.1 which is in use the upper end is easily accessible. As shown in Figure 1 , the ends 22.1 and 22.2 of the body 12 have openings which are closed off in the drawings of Figure 1 by means of closures or lids 24 and 26 respectively. The lids 24 and 26 are also referred to as end caps. The ends caps 24 and 26 are removably connectable to flanges 28 and 30 respectfully. As shown in Figure 2, the flanges 28 and 30 are circular in shape.

Returning now to Figure 1, the end caps 24 and 26 are secured to the flanges 28 and 30 by means of fasteners 32, such as bolts for example. The bolted connection between the end caps and flanges provides for a secure, water-tight connection while allowing quick and easy access to the internal chamber 18 of the body 12. It should be clear that the bolts 32 are received in aligned, threaded passages located in the caps 24, 26 and the body 12 in order to secure the lids to the body. Seals 34 allow for a watertight connection between the flanges 28 and 30, and therefore the body 12, and the end caps 24 and 26. Referring still to Figure 1 it can be seen that the inlet 14 and outlet 16 of the body 12 have spigots which carry connecting flanges 36 and 38 respectively. In use, the connecting flanges 36 and 38 connect the body 12, and accordingly the strainer 10, to corresponding flanges of a pipeline (not shown in the accompanying drawings). The connecting flanges 36 and 38 of the inlet 14 and outlet 16 carry connecting holes 40 in which fasteners (not shown in the accompanying drawings) are received to connect the strainer 10 to the corresponding connecting flanges on the pipeline. From Figure 1 it should be understood that the strainer 10 is, in use, connected to the pipeline in such a manner that the fluid flow path between the inlet 14 and outlet 16 are in line with the centre axis of the pipeline and therefore also the water flow direction in the pipeline. In this configuration the longitudinal centre line of the body 12 is perpendicular to the flow direction,

1. e. the centreline of the pipeline.

The strainer 10 further includes a filtration element 42, also referred to as a cartridge or filter cartridge, which is connectabie to the body 12 in a position wherein it is located inside the chamber 18. The filtration element 42 is, in use, mounted in such a position inside the chamber 18 in which it is located in the fluid flow path between the iniet 14 and outlet 16.

From Figures 1 and 2 it can be seen that the filtration element is substantially cylindrical in shape and has two longitudinally opposed ends

44.1 and 44.2. The filtration element 42 has an outer or side wall 46 defining the cylindrical shape while the ends 44.1 and 44.2 are closed off by means of end walls 48.1 and 48.2. The side wall 46 and end walls 48.1,

48.2 are manufactured from perforated sheeting or woven mesh or mesh- like material. It is envisaged that the filtration element 42 could be manufactured by rolling a sheet of woven mesh or perforated material and welding two opposed edges thereof to one another to create the cylindrical side wall 46. A flat circular disc, which is typically of the same thickness than the side wall, is then welded onto the edges of the two ends 44.1 and 44.2 of the side wall 46. As shown in the drawings and in particular Figure

2, the side wall 46 and end walls 48.1 and 48.2 create a substantially closed off interior volume 50 of the filtration element 42 (except for its outlet opening through which water exits the filtration element). It should be understood that in this context the term closed-off means that the interior volume is substantially enclosed by the mesh-like side wail 46 and end walls 48.1 and 48.2, which allows water to pass through while obstructing foreign matter, also referred to as detritus, from the water.

It is envisaged that the side wall 46 and end walls 48.1 and 48.2 could be manufactured from perforated or slotted stainless steel sheeting. In applications where higher water pressures are expected to be experienced the filtration element 42 could be reinforced with internal heavy duty perforated stainless steel ribs to prevent failure thereof. The ribs could run transverse to the axial centreline of the filtration element 42 and are preferably arranged to prevent the filtration element from imploding.

It is further envisaged that the flat circular disc welded onto the edge of the end 44.1 of the side wall 46 could be made from a solid material. In this embodiment the water would, in use, flow through the side wall 46 and the end wall 48.2 only.

The strainer 10 further includes a locating formation 52 for locating the filtration element 42 inside the chamber 18 of the body 12. In the illustrated embodiment of Figures 1 and 2 of the strainer 10 the locating formation 52 is located on the filtration element 42. The locating formation 52 is shaped to engage the body 12 of the strainer 10. In the strainer 10 the locating formation 52 on the filtration element 42 is in the form of a protrusion extending from its side wall 46. As shown in Figures 1 and 2 the locating formation 52 protrudes substantially perpendicularly from the side wall 46 such that it is, in use, substantially parallel to the flow direction 20 of the water. The locating formation 52 is also located in a position on the side wail 46 such that it is substantially aligned with the inlet 14 and outlet 16 of the body 12. In the embodiment of Figure 1 and 2 the locating formation 52 Is shaped to engage an internal surface of the outlet 16 and in particular the internal surface of the spigot or connecting flange 38 at the outlet 16. In this configuration the outlet forms a locating formation on the body 12 which is complementally shaped to the locating formation 52 carried by the filtration element 42. It should therefore be understood that in this embodiment of the strainer 10 the locating formation 52, also referred to as the protrusion, is annular or tubular so that it fits into the opening at the outlet 16 when mounted in its operative position inside the chamber 18. It should be clear that the locating formation 52 locates the filtration element 42 in position inside the chamber 18.

It should be understood that the length of the locating formation 52 could vary so as to vary the position of the filtration element 42 inside the chamber 18. By varying the length of the locating formation 52 the distance between the side wall 46 and the inlet 14 and outlet 16 respectively is varied.

Turning now to Figure 2, the strainer 10 further has stops 54 against which the filtration element 42 and in particular its locating formation 52 locates, in use when mounted in position inside the chamber 18. The stops 54 are located in a position wherein it locates the filtration element 42 inside the chamber 42 in a direction in line with the water flow direction 20. From Figure 2 it should be understood that the stops 54 prevents the filtration element 42 from moving in the water flow direction beyond the stops. It should further be clear that the water pressure in use will force the filtration element 42 and in particular its locating formation 52 into a position wherein it locates against the stops 54. This arrangement enables substantially 360° utilisation of the cylindrical side wall surface area for filtration.

It should be understood that the locating formation 52 not only locates and/or connects the filtration element 42 to the body 12, it also acts to seal off the outlet 16, particularly the outlet opening. The manner in which the filtration element 42 engages the outlet 16 forces water to flow into the filtration element prior to exiting the outlet 16. The filtration element 42 therefore substantially seals off the outlet 16. The location formation 42 can therefore be said to be sealing means for sealing off the outlet 16.

Considering that the locating formation 52 also secures the filtration element 42 to the body 12 it can also be described as securing means.

It is also envisaged that the filtration element 42 could be connectable to the removable end cap 24. Referring in particular to Figure 1 the filtration element 42 is shown to be connectable to the end cap 24 by means of fasteners 56. in this embodiment in which the filtration element 42 is connected to the end cap 24 the filtration element may be removed together with the end cap, thereby facilitating easy removal of the filtration element 42 from the chamber 18. The end cap 24 is also referred to as an inspection or maintenance cap that closes off the access opening located at the end 22.1 in the body 12. It should be understood that the inspection cap 24 allows for access to the filtration element 42 located in the body through the access opening when the cap is removed, thereby allowing for inspection and maintenance to be carried out.

However, it is envisaged that in an alternative embodiment of the strainer in accordance with the invention the filtration element 42 may be separate or detached from the inspection cap 24 so that the cap and filtration element are independently removable from the chamber 18 of the body 12. In the alternative embodiment the inspection cap 24 will be removed first. Thereafter, the filtration element 42 will be moved in a direction away from the outlet 16 so as to disengage the locating formation 52 from the outlet opening, which is also the corresponding locating formation of the body 12. After disengagement of the locating formations the filtration element 42 can simply be removed from the chamber 18 through the access opening at the end 22.1 of the body 12.

From the above description of the arrangement of the filtration element 42 inside the chamber 18 it should be understood that the filtration element is transverse to the flow direction of water into the inlet and/or out of the outlet. In the accompanying drawings the filtration element 42 is substantially perpendicular to the water flow direction. In other words, the longitudinal axis of the filtration element 42 is transverse, for example perpendicular, to the water flow direction. It can also be said that the filtration element 42 is a cross-flow element in view of the cross-flow configuration in which it is mounted inside the chamber 18 relative to the water flow direction. It is envisaged that, in use, the filtration element 42 will be substantially upright or vertical. It is however envisaged that, depending on the available space inside an existing old valve and water meter chamber, the filtration element 42 could be mounted transversely to the water flow direction. For example, the filtration element 42 could be mounted at an angle of between about 30 and 60 degrees to the vertical 90° plane, i.e. the central axis of the valve.

Returning now to Figure 1, the opening at the end 22.2 of the body 12 could be used as a drainage or scour opening. By removing the removable end cap 46 the chamber 18 is opened to allow the detritus to be dispensed from the chamber 18. In the event that the body 12 is mounted upright as described above, the detritus will be dispensed from the chamber 18 under gravity.

Referring now to Figure 3, a non-limiting example of an inline fluid strainer in accordance with a second embodiment of the invention will be described. In this ftgure the second embodiment of the strainer is indicated by the numeral 60. Again, like numerals indicate like features.

The strainer 60 is substantially identical to the strainer 10 in accordance with the first embodiment of the invention apart from the design of the end 22.2 of the body 12. In this second embodiment, the strainer 60 has an intermediate section 62 which is connectabie to the flange 30. Again, the intermediate section 62 is connected to the flange 30 by means of fasteners 64 so that it is easily removable. The intermediate section 62 defines a necking formation 66 which reduces the size of the drainage opening. In this second embodiment the drainage opening is located at the end of the necking formation 66 and is closed off by a removable drainage cap 68. Accordingly, the intermediate section 62 is said to be connectabie between the body 12 of the strainer and the drainage cap 68. It is envisaged that the drainage cap 68 could also be replaced by a flanged isolating valve, such as a Resilient Seal Valve (RSV) Gate or butterfly valve.

Referring now to Figure 4, a non-limiting example of an inline fluid strainer in accordance with a third embodiment of the invention will be described. In this figure the third embodiment of the strainer is indicated by the numeral 70. Again, like numerals indicate like features.

The inline fluid strainer 70 is substantially similar to the strainer 10 except for its flanges. In particular, the flanges 36 and 38 of the strainer 10 for connecting the inlet 14 and outlet 16 to adjoining pipes, for example, have been replaced by slip ring flange assemblies 72 and 74. Each slip ring flange assembly 72, 74 carries a flange 72.1, 74.1, which is connected to the inlet 14 and outlet 16 respectively, and a movable slip ring 72.2, 74.2. Unlike the first embodiment of the strainer 10, the flanges 72.1 , 72.2 do not carry any holes, instead, the holes 75 for receiving fasteners 76 (Figure 6) are located in the slip rings 72.2, 74.2. Figure 5 shows an end view of the outlet 16 in which the position of the slip ring 74.2 about the spigot carrying the flange 74.1 can be seen clearly. The fastener receiving holes 75 are located radially outside the diameter of the flange 74.1 so that the fasteners 75 are unobstructed by the flange 74.1 , in use.

Figure 6 shows the outlet 16, in use, connected to a section of a pipe 200 carrying a rigid flange 202. From this figure it can been seen that the fasteners 76 extend through the rigid flange 202 of the pipe 200 and the holes in the slip ring 74.2, such that the flange 74.1 is trapped between the rigid flange 202 and the slip ring 74.2. Tightening of the fasteners 76 presses the slip ring 74.2 against the flange 74.1 and towards the rigid flange 202, thereby connecting the outlet 16 to the pipe 200. In this illustrated embodiment a gasket 78 is located between the flange 74.1 and the rigid flange 202. It should be understood that the gasket 78 is used to provide a watertight connection between the flange 74.1 and the rigid flange 202, and accordingly between the outlet 16 and pipe 200.

An advantage of the slip ring flanges 72, 74 is that the orientation of the body 12 can be changed. In this embodiment the fasteners 76 do not prevent the body 12, and accordingly the chamber 18 and filtration element 42, from being rotated. As a result, the strainer 70 can be used in confined spaces where the vertical dimension of the chamber 18 would otherwise have obstructed installation of the strainer. Figure 7 shows an example of where the body 12, and accordingly the chamber 18 and filtration element 42, has been rotated to allow for installation of the strainer 70. In this figure, the body is rotated by an angle a, which is about 45 degrees in the drawing. It can be seen that rotation of the body 12 reduces the vertical space required to install the strainer 70. In use, the strainer 70 is typically installed on a reinforced cast concrete floor (not shown). In many installations the centreline of the pipework is relative close to the floor and, if not for the rotatability of the body 12, would have posed an obstacle to the installation of the strainer 10 or at least limit the dimension of the filtration element 42. In Figure 7 the reference numeral 79 is used to denote detritus that is collected, in use, at the bottom of the chamber 18.

Returning to Figure 4, it can be seen that the flanges, to which the ends caps 24 and 26 are removably connectable, also different from the flanges 28 and 30 of the strainer 10 of the first embodiment. The flange 80 extends radially inwardly to assist with the locating of the filtration element 42. In this particular embodiment the flange 80 is dimensioned so that it is, in use, in close proximity to or abuts the filtration element 42. The flange to which the end cap 26 is connectable is again in the form of a slip ring flange 82. Similarly to the slip ring flanges 72 and 74, the slip ring flange 82 has a flange 82.1 and a movable slip ring 82.2. The slip ring flange 82 functions in the same manner as the slip ring flanges 72 and 74, and will accordingly not be described again. Referring now to Figure 8, a non-limiting example of an inline fluid strainer in accordance with a fourth embodiment of the invention will be described. In this figure the fourth embodiment of the strainer is indicated by the numeral 90. Again, like numerals indicate like features.

The strainer 90 is substantially similar to the strainer 70. The only difference between these two embodiments is the ratio between the inlet 14 and outlet 16, and the dimensions of the body 12. This embodiment aims to illustrate that the ratios between diameter of the body 12 and the size of the inlet 14 and/or outlet 16 opening(s) may vary. For example, the size of the inlet 14 and/or outlet 16 are not limited in relation to the larger cartridge chamber 18. It is envisaged that the cylindrical chamber 18 diameter may be enlarged to a much greater ratio in comparison to the inlet 14 and outlet 16. It follows that the chamber 18 and therefore the filtration element 42 may be tailored to suit specific customer requirements.

Referring now to Figure 9, a non-limiting example of an inline fluid strainer in accordance with a fifth embodiment of the invention will be described. In this figure the fifth embodiment of the strainer is indicated by the numeral 100. Again, like numerals indicate like features.

The strainer 100 is again substantially similar to the strainer 70. However, the strainer 100 carries an intermediate section 102 which is connectable to the body 12. In particular, the intermediate section 102 is connectable to the slip ring flange 82 by means of fasteners 104 so that it is easily removable. In use, the intermediate section 102 forms a dirt trap for collecting the detritus removed from the water flow. The intermediate section 102 carries an outlet 106, which is referred to as a scour outlet, through which the accumulated detritus/dirt may be flushed. The scour outlet 106 carries a flange 108 for In comparison with the second embodiment of the strainer 60, the dirt trap 102 has a greater volume than that of the strainer 60. it should be understood that the size and/or design of the dirt trap could be varied according to the requirements of a particular installation.

Referring now to Figure 10, a non-limiting example of an inline fluid strainer in accordance with a sixth embodiment of the invention will be described, in this figure the sixth embodiment of the strainer is indicated by the numeral 110. Again, like numerals indicate like features.

In this embodiment of the strainer 110 the inlet 14 and outlet 16 are offset or staggered. In particular, the inlet 14 and outlet 16 are offset in two planes. As shown in Figure 10 the inlet 14 and outlet 16 are offset along the axial centreline of the body 12. With particular reference to the orientation of the strainer 110 as shown in Figure 11, the iniet 14 and outlet 16 could be said to be vertically offset. Turning now to Figure 11 it can be seen that the iniet 14 and outlet 16 are offset in second place, which is perpendicular to the first, vertical plane. In this particular configuration shown in the drawings the second plane is also said to be a horizontal plane. Referring in particular to Figure 11, the inlet 14 and outlet 16 are diametrically offset. In particular, the inlet 14 and outlet 16 are tangential.

As a result of the staggered, tangential inlet 14 and outlet 16, the strainer 110 is prone to create a swirling effect where the water flows in a spiral pattern from the top, where the inlet 14 is located, to the bottom of the strainer, where the outlet 16 is located. It is envisaged that this arrangement would be particularly useful in raw water processing applications, such as filtering water from lakes, dams, rivers and the like.

Referring now to Figure 12, a non-limiting example of an inline fluid strainer in accordance with a seventh embodiment of the invention will be described. In this figure the seventh embodiment of the strainer is indicated by the numeral 120. Again, like numerals indicate like features.

The strainer 120 is substantially simitar to the strainer 70 apart from the construction of its filtration element 122 and, in particular, the method of supporting the filtration element 122 in the chamber 18. In this embodiment of the strainer 120 the filtration element 122 is connectable to the body 12 at the outlet 16 by means of a T-pieoe 124. In this illustrated embodiment the T-piece 124 is made from stainless steef. It carries a stub end 126.1 and two opposed ends 128. and 128.2. The stub end 126 is used to connect the T-piece 124 to the outlet 16, whilst each end 128.1, 128.2 carries a section of the filtration element 122. A piece of woven mesh-like perforated sheeting or any other screening material is connected, typically welded, to each end 128.1 and 128.2. En Figure 12 the sections of the filtration element 122 carried by the ends 128.1 and 128.2 are indicated by the reference signs 130.1 and 130.2 respectively. It is envisaged that the longitudinal length of the filtration element 122 could be enlarged to compensate for the loss of free flow open area of the filtration element due to the T-piece 124.

From the above description of the T-piece 124 it should be understood that the stub 126 forms a location formation substantially similar to the location formation 52 of the strainer 10 according to the first embodiment.

It is envisaged that the strainers 10, 60, 70, 90, 100, 110, 120 could also include pressure gauges (Figure 2) for measuring and displaying the pressure at the inlet 14 and outlet 16. These pressure readings could then be used to determine when cleaning of the filtration element 42, 122 is required. It is welt known that the pressure differential between the inlet 14 and outlet 16 will increase proportionally with the degree of clogging of the filtration element 42, 122. This pressure differential could therefore be an indication of when the filtration element 42, 122 requires cleaning.

It is further envisaged that the strainer in accordance with the invention, in particular the body, could either be fabricated or cast. It should also be kept in mind that the particular dimensions of the strainer will vary according to the particular application which prefers to be used. Operational design pressures will have an effect on the dimensions of the strainer. In view of the above description of the fluid strainers 10, 60, 70, 90, 100, 110, 120 it should be understood that detritus is removed from the water flow stream by forcing the water through the filtration element 42. An advantage of the orientation of the filtration element 42, 122 inside the chamber 18 is that the water flows through the filtration element 42, 122 over the majority, and substantially the entire, surface area of the side wait 46 as well as at least the surface area of the end wall 48.2. As a result, the ratio of open surface area of the filtration element 42, 122 used for filtering water to the cross-sectional area of the water flow stream is increased considerably, compared to known strainers, without having to increase the flange face to face dimension.

Another advantage of the arrangement of the filtering element 42, 122 inside the chamber 18 is that the water, in use, flows from the outside of the filtration element 42, 122 towards the inside. In the event of a failure of the filtration element 42, 122 the flow of water from the outside to the inside of the filtration element is more likely to cause an implosion than an explosion.

Yet another advantage of the strainers 10, 60, 70, 90, 100, 110, 120 in accordance with the invention is that the design is simplified significantly with a much shorter flange face to face (F-F) dimension with larger filter free flow open area, in comparison to known strainers currently available in the market. This simplified design reduces production costs considerably which, in turn, reduces the sales price. In addition thereto, the resulting cost saving in the construction of water meter and control valve chambers, due to the shorter F-F dimension is substantial. The strainers 10, 60, 70, 90, 100, 110, 120 further provides for quick and easy installation and removal of the filtration element 42, 122 when carrying out maintenance, for example. From the above description it should be clear that once the removable cap 24 is removed from the body 12 no other tools are required to remove the filtration element 42, 122 and install it again after cleaning or replacing it with a replacement element. It is therefore believed that the strainer in accordance with the invention also reduces maintenance time and costs. It is further believed that the shape of the filtration element of the strainer in accordance with the invention is particularly resistant to damage and deformation in use. This is due to the configuration and material selected in the manufacturing of the filtration element.

From the above description it should be clear that the strainer 10, 60, 70, 90, 100, 110, 120 in accordance with the invention does not collect detritus inside its cartridge or filtration element. In contrast to known strainers the strainer according to the invention has a closed-off filtration element defining an internal volume into which water flows through a majority of the surface area of the filtration element so that water is filtered as it flows into the internal volume of the filtration element. Unlike known strainers the filtration element 42, 122 of the strainer according to the invention engages the outlet 16 of the strainer, thereby forcing water to pass through into the internal volume of the filtration element prior to exiting the strainer.

It will be appreciated that the above are only some embodiments of the invention and that there may be many variations without departing from the spirit and/or the scope of the invention, ft is easily understood from the present application that the particular features of the present invention, as generally described and illustrated in the figures, can be arranged and designed according to a wide variety of different configurations. In this way, the description of the present invention and the related figures are not provided to limit the scope of the invention but simply represent selected embodiments.

The skilled person will understand that the technical characteristics of a given embodiment can in fact be combined with characteristics of another embodiment, unless otherwise expressed or it is evident that these characteristics are incompatible. Also, the technical characteristics described in a given embodiment can be isolated from the other characteristics of this embodiment unless otherwise expressed.