GB2506148A

GB2506148A - Flange assembly

Info

Publication number: GB2506148A
Application number: GB1216906.6A
Authority: GB
Inventors: Keith Macandrew Haggart
Original assignee: VERDER Ltd
Current assignee: VERDER Ltd
Priority date: 2012-09-21
Filing date: 2012-09-21
Publication date: 2014-03-26
Anticipated expiration: 2032-09-21
Also published as: GB201216906D0; GB2506148B

Abstract

A flange assembly for connecting an inlet/outlet pipe to a pump comprises a mounting block and a flange plate. The mounting block has a proximal end for attachment to the pump, a distal end for connection to the inlet/outlet pipe, a fluid duct connecting the proximal and distal ends, and one or more mounting block lugs. The flange plate, which is for connection to a complementary flange on the inlet/outlet pipe, has one or more flange plate lugs. The mounting block lugs and flange plate lugs can be selectively interlocked, thereby attaching the flange plate to the mounting block.

Description

FLANGE ASSEMBLY

The present invention relates to a flange assembly of the kind that may be used, for example, on pumps such as peristaltic pumps to enable the connection of fluid inlet or outlet pipes thereto.

When connecting a fluid inlet or outlet pipe to a pump such as a peristaltic pump, it is commonplace to attach a flange to the pump and a complementary flange to the pipe. The flanges are bolted together (the bolts passing through holes spaced around the peripheries of the flanges) to connect the pipe, with a gasket placed between the two to seal the joint.

Attaching the flange to the pump is usually achieved by attaching a mounting block, with an integral flange, to the pump. The flange is located on the distal end of the mounting block (that is to say the end furthest from the pump when the mounting block is attached), and an attachment plate is located on its proximal end (the end nearest the pump when the mounting block is attached). The mounting block is bolted to the pump through holes in the attachment plate. To allow access with a tightening tool to bolts inserted into the holes in the attachment plate, the mounting block is manufactured such that each hole in the attachment plate is aligned with one of the holes in the flange. The holes in the flange are oversized. This allows a bolt to be driven through a hole in the attachment plate by passing the tightening tool through the corresponding hole in the flange.

The above arrangement is limited in a number of ways. Firstly, the necessity for each hole in the attachment plate to be aligned with a hole in the flange places design constraints on the mounting block, as well as the pump. It may also make the attachment process awkward and time consuming. In addition, the holes in the flange being oversized necessitates the use of oversize bolts, which in turn necessitates the use of similarly oversized holes in the complementary flange attached to the inlet/outlet pipe. Furthermore, the flanges may have to be made larger or of a stronger material in order to compensate for the weak-spots introduced into the component by the oversized holes. Use of stronger materials or larger flanges may increase raw material cost and/or machining time, and may increase the weight and/or bulk of the finished components.

An alternative solution is to utilise a flange assembly comprising a mounting block with a removable flange plate. In such an arrangement the mounting block is bolted to the pump (through holes in the attachment plate, as above) with the flange plate detached. Once the mounting block is attached to the pump, the flange plate placed around the end of the mounting block and secured in place using a snap ring.

Although this arrangement may simplify the mounting block attachment process and negate the need for oversized holes in the flange, insertion of a snap ring to secure the flange plate (and removal of the snap ring if necessary) is an awkward process. In addition, in some circumstances the flange plate can be subject to high forces which the snap ring is not be able to withstand.

It is one object of the present invention to mitigate or obviate one or more of the aforesaid disadvantages, and/or to provide an improved or alternative flange assembly, mounting block, flange plate and/or pump.

According to a first aspect of the present invention there is provided a flange assembly for connecting an inlet/outlet pipe to a pump, the flange assembly comprising: a mounting block having a proximal end for attachment to the pump, a distal end for connection to the inlet/outlet pipe, a fluid duct connecting the proximal and distal ends, and one or more mounting block lugs; and a flange plate for connection to a complementary flange on the inlet/outlet pipe, the flange plate having one or more flange plate lugs, wherein the mounting block lugs and flange plate lugs can be selectively interlocked, thereby attaching the flange plate to the mounting block.

The above arrangement may provide the advantages discussed above in relation to a flange assembly with a removable flange, i.e. the mounting block attachment process is simplified and the requirement for oversized holes in the flange is negated. In addition, the use of interlocking lugs may provide an attachment mechanism that allows the flange plate to be attached to and detached from the mounting block with advantageous speed. Also, such an attachment mechanism may exhibit improved ease of use and/or increased strength.

The flange plate may be flat and circular, for example it may be shaped to comply with an industry standard, or it may have any other suitable shape. The flange plate may or may not have one or more fastener apertures such as holes or notches for receiving bolts or other fasteners. The distal end may be directly or indirectly connectable to the inlet/outlet pipe.

The flange plate may have a through-bore, the through-bore being aligned with the fluid duct when the mounting block lugs and flange plate lugs are interlocked. The through-bore in the flange plate may be circular or may have any other suitable cross sectional shape, may or may not run in a direction normal to the plane of the flange plate, and may or may not be positioned at the centre of the flange plate. The through-bore may be a fully enclosed bore, or may include an open region (for instance the flange plate may be in the shape of a C or a U).

The mounting block lugs and flange plate lugs may be interlockable via rotation of the mounting block and flange plate relative to one another. Alternatively, they may be interlockable via relative linear motion, a combination of linear and rotary motion, or via any other suitable type of relative movement.

Where the mounting block lugs and flange plate lugs are interlockable via rotation of the mounting block and flange plate relative to one another, in one embodiment the relative rotation of the mounting block and flange plate by which the flange plate lugs and mounting block lugs are interlockable defines a rotational axis, the mounting block lugs and flange plate lugs projecting in substantially radial directions about the rotational axis when interlocked. The mounting block lugs and/or flange plate lugs may instead project substantially tangentially or circumferentially, or in any other suitable direction. The lugs may be mounted on support structures such as rods running along the rotational axis.

In the above embodiment, where the flange assembly has a through bore the mounting block lugs may project substantially radially outwards from the mounting block and the flange plate lugs may project substantially radially inwards into the through-bore in the flange plate. The mounting block lugs may instead project substantially radially inwards and/or project from a different portion of the mounting block. Similarly, the flange plate lugs may instead project substantially radially outwards, and/or not project into the through-bore.

The fluid duct may be provided by an insert, the insert being secured within the mounting block. The fluid duct may instead be integral, for instance it may be a through-bore running along or substantially parallel to a centre-line of the mounting block (such as the coupling axis or mounting block longitudinal axis discussed below). Where the fluid duct is provided by an insert, the insert may be held within mounting block mechanically, for instance the mounting block may consist of multiple sections joined together around the insert, e.g. around a narrowed waist portion of the insert. The insert may be held in place via an interference fit, or the mounting block may be cast or moulded around the insert. Alternatively, the insert may be secured using adhesives, welding, soldering, or by any other suitable method.

One or more of the mounting block lugs and/or flange plate lugs may be provided with a pair of retaining walls positioned to receive an interlocking lug therebetween. The retaining walls may be spaced so as to substantially prevent lateral movement of the lug that is received therebetween, or may be spaced so as to allow a degree of lateral movement of the lug between the retaining walls. Retaining walls may be provided on one, some or all flange plate lugs and/or one, some or all mounting block lugs. For instance, retaining walls may be provided on all the flange plate lugs and none of the mounting block lugs. In some embodiments one or both of the retaining walls may be slanted to form a valley therebetween. The slanted walls of the valley may provide a centring action, camming the corresponding interlocked lug into position when the lugs are urged together.

The assembly may have three or more mounting block lugs and three or more flange plate lugs. The assembly may instead have a single mounting block lug and a single flange plate lug (though some form of stabilisation elements may be necessary in such an arrangement), or two mounting block lugs and two flange plate lugs. The assembly may or may not have equal numbers of flange plate lugs and mounting block lugs.

The mounting block lugs and flange plate lugs may be substantially evenly spaced about the mounting block and flange plate respectively. For instance, the mounting block lugs and/or flange plate lugs may be arranged in one or more annular arrays. Alternatively one or more of the flange plate lugs and/or mounting block lugs may be irregularly spaced, in one or more annular arrays or otherwise.

The fluid duct may extend through a conical tail piece, the conical tail piece projecting from the proximal end of the mounting block, away from the distal end.

Instead, the proximal end of the housing may be substantially flat or may have a rounded tail piece, and/or have a conical indentation therein. Alternatively, the proximal end of the mounting block may have a conical tail piece through which the fluid duct does not extend, or the proximal end may take any other suitable form. The conical tail piece and/or indentation, where present, may be an exact cone or may be pyramidal, trumpet-shaped or ogival. The tail piece and/or indentation may have a pointed tip, a flat tip or a tip of any other suitable shape.

The distal end of the mounting block may have an abutment face which surrounds a mouth of the fluid duct, the abutment face being configured to be secured against a complementary abutment face on the inlet/outlet pipe. In use, the abutment face may be secured directly against the complementary abutment face on the inlet/outlet pipe, or indirectly e.g. through a gasket or other suitable sealing element.

In one embodiment where the flange plate has a through-bore, the mounting block lugs and flange plate lugs are positioned to be interlockable when the distal end of the mounting block is received within the through-bore in the flange plate. In this embodiment the distal end of the mounting block may be received in the through bore so that it passes all the way through the flange plate, or alternatively it may be received such that it projects into the through-bore but does not extend fully through it. In other words, after insertion distal end of the mounting block may project beyond, be substantially flush with, or be recessed beneath the surface of the flange plate.

Alternatively, the mounting block lugs and flange plate lugs may be positioned to be interlockable when the distal end of the mounting block as placed against the flange plate, or when the flange plate and the mounting block are arranged in any other suitable relative position.

In the above embodiment, the mounting block and/or flange plate may have a stop member positioned to prevent over-insertion of the distal end of the mounting block into the through-bore in the flange plate. The stop member may be a lip or a peg, or may take any other suitable form.

In further embodiment, the proximal end of the mounting block has a plurality of apertures for receiving elongate fasteners by which the mounting block can be attached to the pump. The apertures may be fully enclosed holes, or may be notches or open-sided holes.

In the above embodiment, the mounting block may define a mounting block longitudinal axis, the apertures being situated at angular displacements around the mounting block longitudinal axis that lie between the angular displacements of the mounting block lugs. Each fastener aperture may be at an angular displacement substantially half way between the angular displacements of two adjacent mounting block lugs, in other words the fastener aperture may be angularly equidistant to the two adjacent apertures. Alternatively, the mounting block lugs and apertures may be in any suitable angular distribution. There may be more than one aperture at an angular displacement between the angular displacements of two adjacent mounting block lugs, and/or there may be two adjacent mounting block lugs with no apertures lying at angular displacements therebetween. The apertures and/or mounting block lugs may be arranged in one or more a regularly-spaced or irregularly-spaced annular arrays.

According to a second aspect of the present invention there is provided a mounting block for use in the flange assembly according the first aspect of the present invention.

According to a third aspect of the present invention there is provided a flange plate for use in the flange assembly according to the first aspect of the present invention.

According to a fourth aspect of the present invention there is provided a pump comprising the flange assembly according to the first aspect of the present invention or a mounting block according to the second aspect of the invention.

The pump may be a peristaltic pump. Alternatively, it may be any other suitable type of pump.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of a first embodiment of the invention; Figure 2 is a perspective view of two of the flange assemblies of figure 1, mounted to a peristaltic pump; Figure 3 is a perspective view of second embodiment of the invention in its component parts; and Figure 4 is a perspective view of the second embodiment of the invention in assembled form.

Referring now to the drawings, figure 1 shows a flange assembly according to a first embodiment of the invention. The flange assembly has a mounting block 2 and a flange plate 4. The mounting block 2 is generally elongate. It has a proximal end 6 configured to be attached to a pump, and a distal end 8 configured to be connected to an inlet/outlet pipe of the pump. The proximal 6 and distal 8 ends of the mounting block 2 are in fluid communication via a fluid duct 10, which takes the form of a through-bore of substantially circular cross section running along the longitudinal axis of the mounting block. The mounting block 2 also has a regularly-spaced annular array of four mounting block lugs 12, each of which projects radially outwards (relative to the longitudinal axis of the mounting block 2) from the distal end 8.

The flange plate 4 is substantially disc-shaped and has four fastener holes 14 evenly spaced around its perimeter. The flange plate 4 is of a standardised size and shape, and the holes 14 are of a standardised size and spacing, so that the flange plate can be connected to a complementary standardised flange situated on the end of a pump inletloutlet pipe (for example via bolts received in the fastener holes 14).

The flange plate 4 has a through-bore 16, and an evenly-spaced annular array of four flange plate lugs 18. Each flange plate lug 18 projects radially inwards (relative to the longitudinal axis of the flange plate 4) into the through-bore 16, and has a pair of retaining walls, in this case a short retaining wall 20 and a tall retaining wall 22. The retaining walls 20, 22 of each pair are spaced to receive one of the mounting block lugs 12 between them.

As outlined in more detail later, the mounting block lugs 12 and flange plate lugs 18 are configured so as to be interlockable, via relative rotation of the flange plate 4 and mounting block 2, thereby securing the flange plate to the mounting block such that the through-bore 16 is aligned with the fluid duct. This relative rotation defines a rotational axis. The mounting block lugs 12 and flange plate lugs 18 are positioned such that they are interlockable when the distal end 8 of the mounting block 2 is received within the through-bore 16 in the flange plate 4. Four stop members in the form of arcuate lips 24 are positioned on the distal end 8 of the mounting block 2 such that they limit the extent to which the distal end 8 of the mounting block 2 can be inserted into the through-bore 16 in the flange plate 4.

At its proximal end 6, the mounting block 2 has a conical tail piece 24 which projects in the opposite direction to the distal end 8. The fluid duct 10 extends substantially centrally along the length of the tail piece 26 and terminates in a mouth at the tip of the tail piece.

The proximal end 6 also comprises a substantially square attachment plate 28 with four fastener apertures 30, one in each corner, shaped to receive elongate fasteners such as bolts (not shown) by which the mounting block 2 can be attached to a pump. The fastener apertures 30 are arranged such that their angular displacements relative to the longitudinal axis of the mounting block 2 lie between the angular displacements of the mounting block lugs 12. In other words, when viewed along the longitudinal axis of the mounting block 2 the fastener apertures 30 lie between the mounting block lugs 12 around the circumference of the mounting block.

In this embodiment, each fastener aperture 30 is at an angular displacement half way between two adjacent mounting block lugs 12, i.e. each fastener aperture lies equidistant between two mounting block lugs, and similarly each mounting block lug lies equidistant between two fastener apertures. With the fastener apertures 30 so arranged, access to them with a tightening tool (to attach the mounting block 2 to a pump via bolts or screws) is not significantly restricted by the mounting block lugs 12.

For the same reason, each lip 24 is positioned at an angular displacement substantially equal to one of the mounting block lugs 12. On the flange plate 4 however, the fastener holes 14 are positioned at angular displacements such that each fastener hole lies within one of the flange plate lugs 18. This is advantageous in that the material of the flange plate lugs 18 provides extra strength around the fastener holes 14, which in turn allows the holes to be closer to the centre of the flange plate 4 and thus allows the flange plate to be smaller in diameter.

At its distal end 8, the mounting block 2 has an abutment face 32 which surrounds another mouth of the fluid duct 10. The abutment face is substantially smooth and flat, and is configured to be securable against a complementary abutment face on an inlet/outlet pipe, as outlined below.

Figure 2 shows the flange assembly with the flange plate 4 connected to the mounting block 2. The flange assembly is attached to a pump 34 by four bolts 36 passing through the apertures (not visible in figure 2) in the attachment plate 28. As figure 2 shows, in this embodiment with the mounting block lugs 12 and flange plate lugs 18 interlocked the longitudinal axes of the mounting block 2 and flange plate 4 are in line with the rotational axis. When the mounting block lugs 12 and flange plate lugs 18 are aligned, therefore, each mounting block lug 12 projects radially outwards relative to the rotational axis and each flange plate lug 18 projects radially inwards relative to the rotational axis. In other words, the mounting block lugs 12 and flange plate lugs 18 project in radial directions relative to the rotational axis, as well as relative to the longitudinal axes of the mounting block 2 and flange plate 4 respectively.

As is also apparent from figure 2, the abutment face 32 projects beyond the surface of the flange plate 4. In this case, therefore, the fluid duct 10 is not only aligned with the through-bore 16 but also runs fully through it.

A method of using the flange assembly of the first embodiment will now be described with reference to figures 1 and 2.

To attach the mounting block 2 to a peristaltic pump 34 (with the flange plate 4 not connected to the mounting block), the mounting block is positioned so that the fastener apertures 30 in the attachment plate 28 are aligned with corresponding threaded apertures (not visible) in the pump 34. A bolt 36 is passed through each of the fastener apertures 30 and threadedly engaged with the corresponding threaded aperture in the pump. As the bolts 36 are tightened, they draw the mounting block 2 towards the pump 34. This begins to force the end of the tail piece 26 into the hose (not visible) of the pump 34. Continuing to tighten the bolts 36 pulls the mounting block 2 further towards the pump 34 and forces the end of the tail piece 26 further inside the hose of the pump. Due to its taper, forcing the tail piece 26 further into the hose causes it to engage with the inner surface of the bore in the hose. The hose spreads slightly, accommodating the end of the tail piece 26 and forming a tight seal therewith. This prevents the boundary between the hose of the pump 34 and the mounting block from leaking when the pump is in use.

When the bolts 36 have been fully tightened, the mounting block 2 is attached to the pump 34 and is ready to receive the flange plate 4. To secure the flange plate 4 in place, it is placed onto the mounting block 2 such that the distal end S of the mounting block is received within the through-bore 16. During insertion of the distal end 8 of the mounting block 2 into the through-bore, the flange plate 4 is positioned such that each mounting block lug 12 passes between adjacent flange plate lugs 18.

When the flange plate 4 has passed far enough down the distal end 8 of the mounting block 2 for the mounting block lugs 12 and flange plate lugs 18 to be interlocked, the lips 24 contact the flange plate and prevent it moving any further. At this point the flange plate 4 is rotated, clockwise by around 30° in this embodiment, to interlock the lugs. During this rotation, the shod restraining wall 20 of each flange plate lug 18 moves across a mounting block lug 12. The tall restraining wall 22 then contacts that mounting block lug 12, preventing the flange plate 4 being over-rotated.

At this point the flange plate lugs 18 and mounting block lugs 12 are interlocked.

In order to secure the lugs 12, 18 in their interlocked state, the flange plate 4 is moved so as to withdraw the distal end 8 of the mounting block 2 from the through-bore 16 as far as the interlocked lugs will allow. This urges the interlocked pairs of lugs 12, 18 towards each other, moving each mounting block lug into the space between the two retaining walls 20, 22 of the corresponding flange plate lug. With the mounting block lugs 12 so positioned, the retaining walls 20, 22 restrict the movement of the mounting block lugs, thereby restricting relative rotation of the flange plate 4 and mounting block 2 and maintaining the lugs 12, 18 in their interlocked configuration.

To attach an inlet/outlet pipe to the flange assembly, the end of the pipe is positioned such that an abutment face of the pipe is aligned with the abutment face 32 of the flange assembly, and a flange of the pipe is aligned with the flange plate 4.

The flange of the pipe is positioned so that its holes are in line with the holes 14 in the flange plate 4. With a gasket inserted between the abutment face 32 of the flange assembly and the abutment face of the pipe, the two flanges are clamped together using bolts. This presses the abutment faces together, compressing the gasket and sealing the joint. As the abutment face 32 projects slightly beyond the flange plate 4 (and the same is true of the abutment face and flange of the pipe), the clamping force applied by the bolts passes entirely through the junction between the abutment faces, rather than any passing through the junction between the flanges. This not only ensures that a strong seal is provided, but also maintains a force urging the flange plate 4 to be withdrawn from the mounting block 2. This urges the mounting block lugs 12 against the flange plate lugs 18, keeping the mounting block lugs firmly seated between the restraining walls 20, 22 of the flange plate lugs.

The procedures by which the pipe can be detached from the flange assembly, the flange plate 4 can be removed from the mounting block 2 and the mounting block 2 can be removed from the pump 34 are simply the reverse of the above.

The flange assembly of a second embodiment of the invention is shown in dismantled form in figure 3, and in assembled form in figure 4. The flange assembly of the second embodiment is identical to that of the first embodiment with the exception that the mounting block 2 is formed from three distinct parts. The fluid duct 10, tail piece 26 and abutment surface 32 are provided by an insert 38. The insert 38 is sandwiched between two casing portions 40, 42, which form the remainder of the mounting block 2 as described in relation to the first embodiment. In this embodiment the two casing portions 40, 42 are substantially identical, with the exception of two fastener holes 44 on opposite sides of one of the casing portions 40. By inserting a fastener such as a bolt or screw into each of the fastener holes 44 and tightening them, the two housing portions 40, 42 are clamped together around a narrowed waist portion 46 of the insert 38. Once the housing portions 40, 42 are clamped together, the shoulders 48, 50 of the waist portion 46 act to retain them.

The fluid duct 10 (and in this embodiment the tail portion 26 and abutment face 32) being provided by an insert allows the portion of the flange assembly that contacts the medium being pumped to be made from a different material than the structural components. For example, the material from which the insert 38 is made can be selected to optimise its corrosion resistance while the materials from which the flange plate 4 and casing portions 40, 42 is made can be selected to optimise strength. As another example, the material from which the insert 38 is made can be selected to optimise wear resistance, allowing the pumping of abrasive fluids, while the materials from which the flange plate 4 and casing portions 40, 42 are made can be selected to reduce weight or raw material costs. A mounting block of multi-piece design also allows only the affected component(s), rather than the whole mounting block, to be replaced if needed. For instance, a corroded insert 38 or a damaged mounting block lug 12 could be replaced at lower cost than replacing the entire assembly.

It will be appreciated that numerous modifications to the above described design may be made without departing from the scope of the invention as defined by the appended claims. For instance, while in the described embodiments the fluid duct and through-bore are aligned such that the fluid duct passes fully through the through-bore, in other embodiments they may be aligned such that the fluid duct enters the through-bore but does not run all the way through it, or such that the fluid duct does not enter the through-bore at all but is merely arranged such that fluid passing through the through-bore can enter the fluid duct (or vice versa).

In addition, while in the described embodiments the longitudinal axes of the mounting block and flange plate are in line with the rotational axis when the lugs are interlocked, in other embodiments this may not be the case. It is to be understood that in embodiments where the longitudinal axes of one or both of the mounting block and flange plate are not in line with the rotational axis (or where one or more of said axes are not present), the relative position of features that have been described herein in relative to one axis may instead be so positioned relative to a different axis.

For the avoidance of doubt, reference to lugs' herein is intended to cover any suitable elements of an article which perform the function of interlocking with elements extending from another article. For instance, an attachment mechanism akin to those found in a B22d or a GU1O light fitting incorporates lugs as defined herein. While in the embodiments described herein the lugs are projections, in other embodiments this may not be the case. For example, an embodiment where the distal end of the mounting block is substantially square, and is inserted through a substantially square hole in the flange plate before being rotated to prevent withdrawal, is intended to be covered. In this example, the corners of the square portion of the distal end of the mounting block, and the portions of the square hole which are overlapped by said corners, fall under the definition of lugs' as used herein.

The described and illustrated embodiments are to be considered as illustrative and not restrictive in character, it being understood that only preferred embodiments have been shown and described and that all changes and modifications that come within the scope of the invention as defined in the claims are desired to be protected. In relation to the claims, it is intended that when words such as "a," "an," "at least one," or "at least one portion" are used to preface a feature there is no intention to limit the claim to only one such feature unless specifically stated to the contrary in the claim. When the language "at least a portion" and/or "a portion" is used the item can include a portion and/or the entire item unless specifically stated to the contrary.

Optional and/or preferred features as 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 and/or preferred features for each aspect of the invention set out herein are also applicable to any other aspects of the invention, where appropriate.

Claims

CLAIMS1. A flange assembly for connecting an inlet/outlet pipe to a pump, the flange assembly comprising: a mounting block having a proximal end for attachment to the pump, a distal end for connection to the inlet/outlet pipe, a fluid duct connecting the proximal and distal ends, and one or more mounting block lugs; and a flange plate for connection to a complementary flange on the inlet/outlet pipe, the flange plate having one or more flange plate lugs, wherein the mounting block lugs and flange plate lugs can be selectively interlocked, thereby attaching the flange plate to the mounting block.
2. The flange assembly according to claim 1 wherein the flange plate has a through-bore, the through-bore being aligned with the fluid duct when the mounting block lugs and flange plate lugs are interlocked.
3. The flange assembly according to claim 1 or 2 wherein the mounting block lugs and flange plate lugs are interlockable via rotation of the mounting block and flange plate relative to one another.
4. The flange assembly according to claim 3 wherein the relative rotation of the mounting block and flange plate by which the flange plate lugs and mounting block lugs are interlockable defines a rotational axis, the mounting block lugs and flange plate lugs projecting in substantially radial directions about the rotational axis when interlocked.
5. The flange assembly according to claim 3, incorporating claim 2, wherein the mounting block lugs project substantially radially outwards from the mounting block and the flange plate lugs project substantially radially inwards into the through-bore in the flange plate.
6. The flange assembly according to any preceding claim wherein the fluid duct is provided by an insert, the insert being secured within the mounting block.
7. The flange assembly according to any preceding claim wherein one or more of the mounting block lugs and/or flange plate lugs are provided with a pair of retaining walls positioned to receive an interlocking lug therebetween.
8. The flange assembly according to any preceding claim wherein the flange assembly has three or more mounting block lugs and three or more flange plate lugs.
9. The flange assembly according to any preceding claim wherein the mounting block lugs and flange plate lugs are substantially evenly spaced about the mounting block and flange plate respectively.
10. The flange assembly according to any preceding claim wherein the fluid duct extends through a conical tail piece, the conical tail piece projecting from the proximal end of the mounting block, away from the distal end.
11. The flange assembly according to any preceding claim wherein the distal end of the mounting block has an abutment face which surrounds a mouth of the fluid duct, the abutment face being configured to be secured against a complementary abutment face on the inlet/outlet pipe.
12. The flange assembly according to any preceding claim, incorporating claim 2, wherein the mounting block lugs and flange plate lugs are positioned to be interlockable when the distal end of the mounting block is received within the through-bore in the flange plate.
13. The flange assembly according to claim 12 wherein the mounting block and/or flange plate has a stop member positioned to prevent over-insertion of the distal end of the mounting block into the through-bore in the flange plate.
14. The flange assembly according to any preceding claim wherein the proximal end of the mounting block has a plurality of apertures for receiving elongate fasteners by which the mounting block can be attached to the pump.
15. The flange assembly according to claim 14 wherein the mounting block defines a mounting block longitudinal axis, the apertures being situated at angular displacements around the mounting block longitudinal axis that lie between the angular displacements of the mounting block lugs.
16. A flange assembly substantially as hereinbefore described with reference to figures 1 and 2 or figures 3 and 4.
17. A mounting block for use in the flange assembly according to any preceding claim.
18. A flange plate for use in the flange assembly according to any one of claims 1-16.
19. A pump comprising the flange assembly according to any one of claims 1-16 or the mounting block according to claim 17.
20. The pump according to claim 19 wherein the pump is a peristaltic pump.