GB2460543A

GB2460543A - Flange spreader

Info

Publication number: GB2460543A
Application number: GB0909604A
Authority: GB
Inventors: Robert Stephen
Original assignee: Equalizer International Ltd
Current assignee: Equalizer International Ltd
Priority date: 2008-06-05
Filing date: 2009-06-04
Publication date: 2009-12-09
Anticipated expiration: 2029-06-04
Also published as: GB0909604D0; GB2460543B; GB0810231D0

Abstract

A flange spreader (110) provided with a pair of support arms (120 a,b) that can be used to connect the spreader to a pair of opposed flanges. A body (130) connecting the support arms so that they are spaced apart from one another by a gap (120g). A separating tool can be in the form of a wedge member (150) mounted between the arms and be movable relative to the body for driving apart the opposed flanges. The support arms can retain a pin (140) for connecting the arms to the flanges. The pair of arms can present a first gap width between the arms and a second gap width between the arms that is different from the first gap width, for example, by virtue of the arms being non-symmetrical and removable connectable to the body in different rotational positions such that when connected in the different positions, different gaps may be formed between the arms. The wedge member (150) having an axis, and a first and second surfaces that are inclined relative to this axis where the surfaces are arranged at different angles with respect to one another.

Description

Flange Spreader The present invention relates to a flange spreader and in particular, but not exclusively, it relates to a tool which in one embodiment is used to separate opposed flanges of adjacent pipe sections.

In many pipe networks, it is desirable to be able to dismantle or remove assembled components of the pipe system. The pipe system is typically made up of individual pipe sections that are connected at end flanges which protrude radially outwardly at each end of a section, and the flanges are bolted together to connect adjacent sections together through series of circumferentially spaced apart bolt holes extending across the join. In order to change out a pipe section, for example, for repair or maintenance purposes, it is necessary to move the adjacent sections apart. This can be difficult, in particular where such sections to be changed out have been joined very tightly at the flanges or are a close fit between other components, or where the sections are heavy and cannot be easily moved.

When removing sections of pipe from a network, the bolts joining the flanges are removed, and typically the flanges are separated from one another at the joint frequently using a "flange spreader" tool.

An example of such a prior art flange spreader 10 is shown in Figure 1 in use with a pipeline 12 composed of two pipe sections 1 2s, connected together by flanges 1 2f with chamfered edges that come together to form a gap I 2g between the assembled flanges. The flange spreader 10 is provided with a pair of support arms 1 Oa, 1 Ob attached to a body 1 Oc, and has a hydraulically operated wedge 1 Ow which is movable from the hydraulic actuator housing lOh toward the adjoined pipe flanges 12f.

In order to apply sufficient force for moving the flanges 1 2f apart, the spreader 10 is secured against the pipe sections 12s using a pin lOp held at respective ends of the support arms lOa, lOb. The pin is located in a sliding fit through aligned bolt holes 1 2b defining an axial bore through the pipe flanges 1 2f (normally occupied by bolts connecting the pipe sections).

The pins lOp hold the spreader in position relative to the pipeline 12 so that the body 1 Oc is held parallel to the axis of the pipeline 12, and the wedge 1 Ow moves radially with respect to the pipe sections. The spreader is longitudinally aligned by the user relative to the flanges so that a tip of the wedge lOw meets the pipe flanges 12f in the gap 12g. The actuator drives the wedge progressively into this gap 1 2g forcing the flanges 1 2f to separate.

The pipeline sections, flanges and bolt holes to which such flange spreaders need to be applied are often of different dimensions at different sites. If the tool arms have an excessive span for the opposed flanges they are applied to or if the pin has a diameter which too narrow for the bolt holes in which it is located, significant bending moments can arise in the pin due to the leverage provided and reaction force felt by the pin, arms and body due to driving the wedge into engagement with the flanges.

This can cause damage and prevent proper operation of the tool.

For this reason, several individual flange spreaders each configured for use with different pipeline configurations are typically taken to a worksite to enable different flange configurations to be worked on.

According to a first aspect of the invention, there is provided a flange spreader comprising: -a pair of support arms adapted to be connected to a pair of opposed flanges; -a body connecting the support arms so that they are spaced apart from one another by a gap; -a separating device mounted between the arms and movable relative to the body for driving apart the opposed flanges; -wherein the support arms are adapted to retain a connector device for connecting the arms to the flanges; wherein the pair of arms are adapted to present a first gap width between the arms and a second gap width between the arms different from the first gap width.

The flange spreader can be applied to pipes with flanges but could also be applied to other flanged items such as valves, gearboxes, pressure vessels, etc. Typically the support arms are adapted to connect to the body so that they extend away from the body along axes that are generally perpendicular to the axis of the body.

Typically the support arms are connectable to the body in different orientations to define different assembled configurations of the flange spreader, wherein in a first assembled configuration the arms define the first gap width and in a second assembled configuration the arms define the second gap width. More specifically, the support arms may be connectable to the body in different rotational positions about their respective axes, and typically the arms are non-symmetrical about their axes, such that connection of the arms in different rotational positions thereby define different assembled configurations of the spreader and different gap widths between the arms. Where the arms are non-symmetrical, moving the arms around their axes can change the configuration of the arms and thereby can change the gap between them in the assembled flange spreader. The connection between the arms and the body is optionally the same in the different configurations.

The pair of support arms is typically adapted to hold a pin spanning across the first gap width for connecting the arms to opposed flanges of a first pipe flange thickness, and to hold a pin spanning across the second gap width for connecting the arms to opposed flanges of a second, different pipe flange thickness.

Thus, a single tool is provided which provides for separating flanges of adjacent pipe sections with different flange thicknesses.

The tool may include at least one pin adapted to extend across the gap between the arms. The pin may extend to span the first and or second gap widths. In typical embodiments, the connector device can be a single pin spanning across the gap between the arms, and may be adapted to pass through bolt holes in the adjacent flanges. The arms can be adapted to retain the connector device at the ends of the arms distal to the body.

The arms may be adapted at their distal ends to retain a first pin of a first diameter for connecting the arms to bolt holes of the opposed flanges and a second pin of a second diameter for connecting the arms to different bolt holes. The pin can be cylindrical or cuboidal, but typically is adapted to allow the passage of the pin through the flange bolt holes, and allow sliding of the flanges with respect to the pin, as the flanges separate relative to the stationary pin when in use.

Typically the arms are adapted to connect to the body in two separate configurations. In one of the connection configurations, the arms present the first gap width, and in the other configuration, the arms present the second gap width. Typically the arms are also adapted to retain a connector device in two different configurations. In one such configuration, the arms may retain a first connection device, in the form of a first pin, adapted to connect the arms to flanges with large diameter bolt holes, and in a second configuration, the arms may retain a second pin, adapted to connect the arms to flanges with a smaller diameter bolt hole.

Thus, the pins may be different in different configurations of the spreader, for example, a pin used to span the second gap width may be thicker and/or longer than the pin used to span the first gap width.

The arms may have connection portions for detachable connection of the arms thereto. In this way, the arms may be removably, detachably, and/or interchangeably coupled to the body, for example, the arms may be connectable interchangeably to different connecting portions of the body.

The arms may be coupled in a first configuration (for example facing one way on the body) in which a first gap width is defined between the arms, and a second configuration (for example, facing the other way on the body) in which a second gap width is defined between the arms. The arms may be connected to the same connecting portion in different assembled configurations of the spreader. In particular, the connection portions may be cylindrical and the arms may have holes or sleeves for accommodating a cylindrical connecting portion of the body for connection thereto. Typically the same holes or sleeves of the arms can accommodate the cylindrical portions of the body in different configurations of the spreader, so that the connection between the arms and the body is the same in the different configurations.

Typically the arms are non-symmetrical, and may have non-symmetrical faces. For example, in one embodiment, the arms may be identical to one another, but may have recessed portions on at least one face. For example an arm can have one generally flat face and one recessed face.

In this embodiment, the assembled spreader can have three different configurations: a first configuration in which the flat faces of the arms face one another, a second configuration in which the recessed portions of the arms face one another, and a third configuration in which the recessed portion of one arm faces the flat face of the other. The first configuration will have the shortest gap between the arms in the assembled spreader; the second will have the largest, as the depth of the recess will add to the gap, and the third configuration will have a gap intermediate the first and second. Other embodiments can be designed with different gap spacings, by making the recesses larger or smaller. Each of the arms can be recessed, and the depth of the recess in each of the arms can be the same or different. Typically the gap is large enough to accommodate the flange in the assembled spreader.

The arms do not need to be identical to one another, i.e. they may be non-identical to one another. In such embodiments, the arms may still have recessed portions on at least one face but the recessed portions can have different dimensions between the different arms, for example different depths between the two arms, leading to more combinations of gaps using only the two arms.

In some other embodiments, the arms can incorporate a step, so that the connection between the arms and the body can lie in a different plane than the connection between the arms and the connector device and/or pin.

For example, the arms can have an extended (or "lazy") S or Z shape with a first end that is generally disposed in one plane (e.g. the end connected to the body) and a second end that can be spaced apart from the first end and may lie in a different plane generally parallel to the plane of the first end, but vertically spaced therefrom. The spacing between the two planes can be adjusted in accordance with the required dimensions and/or strength of the spreader. For example, if a high strength spreader is required, the size of the step can be reduced to provide a smaller difference in the gaps, so that the distance between the two planes can be reduced to provide a more planar arm. Alternatively if a larger variation between the gaps is required, but a lower strength tool can be used, then the spacing between the planes can be increased. The spacing between the planes can be the same in each arm, or different, giving more combinations. The embodiments having spaced apart planes can also provided with recessed faces as described above.

The arms can have a first set of holes for receiving a pin for connecting the arms to the flanges. A second set of holes can be provided for receiving a second pin. The first and second holes may have different diameters to receive pins of different diameters for different bolt holes.

The separating device can be a wedge device mounted in a cylinder on the body. The separating device can be driven by a screw thread or a hydraulic mechanism. The wedge could also be actuated by a fluid actuation cylinder, such as pneumatic cylinder, or could be actuated by a long lever gaining a mechanical advantage through 2 or more pivots. The body is typically adapted to withstand reaction forces from driving the separating device between the flanges. The body may be adapted to guide movement of the separating device along an axis aligned with a plane separating the opposed flanges.

The invention also provides a wedge member for a flange spreader, the wedge member having an axis, and having first and second surfaces that are inclined relative to the axis of the wedge member for separating the flanges of a pipe, wherein the first and second surfaces are arranged at different angles with respect to one another.

Typically the wedge member is symmetrical about its axis, and has a pair of first angled surfaces, set at the same (but opposite) angle with respect to the axis of the wedge member, and a pair of second angled surfaces set at the same (but opposite) angle with respect to the axis of the wedge member.

Typically the first surface(s) is set at a steeper angle with respect to the wedge member than the second surface(s).

Typically the wedge member tapers toward an apex, which may be set on the axis, and the second surface(s) is optionally closer to the apex than the first surface(s). Typically the first surfaces are arranged at the same distance from the apex, and at opposite sides of the wedge member.

Typically the second surfaces are also arranged at the same distance from the apex (normally closer to the apex than the first surfaces) and are typically arranged on opposite sides of the wedge member.

The apex of the wedge member can optionally have a recess that typically extends parallel to the axis of the wedge member. The recess may be adapted to fit around the connector device or pin of a flange spreader, for example to facilitate extended travel of the wedge member between pipe flanges.

There will now be described by way of example only, embodiments of the invention with reference to the accompanying drawings, of which: Figure 1 is a schematic drawing of a prior art flange spreader in use on a pipeline; Figure 2 is a line drawing of a flange spreader according to an embodiment of the present invention, in a first configuration; Figure 3 is a line drawing of the flange spreader of Figure 2 in a second configuration; Figure 4 is a side view of the flange spreader of Figures 2 and 3, in the first configuration as shown in Figure 2; Figure 5 is a side view of the flange spreader of Figures 2 to 4, in the second configuration as shown in Figure 3; Figure 6 is a perspective representation of the flange spreader in the first configuration as shown in Figure 2; Figure 7 is a perspective representation of the flange spreader in the second configuration as shown in Figure 3; Fig 8 is a side view of a wedge member used for the flange spreader; and Fig 9 is a perspective view from one side of the wedge member of Fig 8 in a cylinder of the flange spreader.

With reference to Figure 2, a flange spreader 110 according to the invention has a pair of support arms 1 20a, 1 20b connected at their proximal ends to a body 130. A gap 1 20g is defined between the arms, and toward distal ends 120e of the arms a pin 140 is held by the arms spanning across the gap 120g. The pin 140 (constituting a "connector device") is removably retained by the arms 1 20a, b so that it can be removed and inserted into bolt holes of opposing pipe flanges to connect the spreader to the pipe flanges. In addition, the spreader has a wedge member 150 (constituting a "separating device") which is movable through a cylindrical housing 1 30c of the main body and in the gap 1 20g so that it is driven into engagement with the flanges (not shown) at their joining faces to move them apart.

The wedge member is shown in more detail in Figs 8 and 9, and is typically symmetrical about a central axis A-A. The wedge member 150 has an apex 151 at one end of the wedge member, which is typically coincident with the axis A-A. The wedge member 150 has a first pair of surfaces 1 52a and 1 52b that are arranged on opposite sides of the wedge member 150, and are inclined relative to the axis A-A of the wedge member 150. The first pair of surfaces 152 diverge from the apex for separating the flanges of a pipe. The wedge member 150 has a second pair of surfaces 1 53a and 1 53b that are also arranged on opposite sides of the wedge member 150 and are inclined relative to the axis A-A of the wedge member 150 and diverge from the apex for separating the flanges of a pipe; however, the angle of the first pair of surfaces 152 is different from the angle of the second pair of surfaces, in that the first pair of surfaces are typically arranged at a steeper angle with respect to the axis of the wedge member 150 than the second pair of surfaces.

The first surfaces are each typically set at an angle of 40° to the axis A-A.

Typically the angle of the first angled surfaces is the same (but opposite) for each of the first surfaces. Likewise the second surfaces are also typically set at the same (but opposite) angle with respect to the axis of the wedge member.

Typically the pair of second surfaces is closer to the apex than the first surfaces.

The apex 151 of the wedge member 150 has a central semi-circular recess 154 to optionally match and accept the diameter of the pin used in the flange spreader.

One advantage of the two different angles on the wedge member is that the initial contact between the wedge member and the flanges is made by the shallower angled second surfaces, which are each typically set at an angle of 30° to the axis A-A. The force needed to prise the flanges apart initially, is often very high, and the amount of separation between the flanges required to effect the initial separation is very low. The shallow angled apical portion of the wedge member therefore takes less force to penetrate the inter-flange space, and perform the initial separation. The flanges then separate at a constant rate dependent on the axial speed of the wedge member and the angle of the second surfaces, until the interface between the first and second surfaces 153, 152 enters the inter-flange space, at which point the flanges start to move apart more rapidly, in response to the steeper angle of the first surfaces. The separation performed by the first surfaces does not require the same amount of force as the initial separation performed by the second surfaces, and so the first surfaces can move the flanges apart from one another more rapidly, and with less force needed. The pin between the arms of the flange spreader can be accommodated within the recess, to permit additional depth for the wedge member 150 to penetrate the inter-flange space.

The support arms 1 20a, 1 20b of the flange spreader are detachably connected to cylindrical cross members 1 30x of the body at respective ends 1 30a, 1 30b of the cross members 1 30x. The arms 120 are stepped and are typically formed in a lazy Z shape, with first (proximal) end portions 121 adapted to connect to the body 130, and second (distal) end portions 125 adapted to connect to the pin. The first end portion 121 typically lies in a different plane than the second end portion 125. The two planes are therefore parallel but spaced apart from one another. Each arm is therefore asymmetrical when viewed in side profile, e.g., as in Figures 2 and 3.

The first end portions 121 have tubular sleeves 122 to receive the cylindrical ends of the cross members 130x, and locking pins 123 that extend radially through the sleeves 122 and restrict relative rotation of each arm 120 around the cross member 130x. The locking pins 123 can also restrict axial translocation of the arms along the axes of the cross members 130x. The locking pins 123 can be radially withdrawn from the sleeves 122 to facilitate removal of the arms from the cross members 130x.

The second (distal) end portions 125 are typically (but not necessarily) parallel to the first end portions 121, but are spaced from the plane of the first portions 121 by a canted portion 126. In this embodiment, the arms each have a first (recessed) face 120p, on which the surfaces of the first 121 and second portions 125 are stepped with respect to one another to lie in planes that are spaced apart, and a second (relatively flatter) face, 1 20q, on which the planes of the first 121 and second 125 portions are more aligned with one another, although there is still optionally a small displacement between the faces of the first 121 and second 125 portions.

The canted portion 126 can have a pair of reinforcing struts 127 connecting it to its sleeve 122. The reinforcing struts 127 can be webbed to the second (relatively flatter) face 1 20q of the first portion 121 and optionally to the same face of the second portion 122 also. Typically the arms are cast or forged as single piece items.

The second portions 125 therefore lie in a different plane than the first portions 121, and the distance between the planes is dependent on the inclination and length of the canted portion 126 formed between them. A similar effect can be achieved by providing arms that have one flat face on one side, and a recessed portion on the other side.

The arms 120a, 120b in this embodiment are shown attached in a first configuration in Figure 2, presenting an across gap length or width 1201 determined by the opposed first faces 120p of the arms 120. In this first configuration the gap between the arms 120 is relatively wide, to accommodate wide flanges between the second end portions 125 of the arms 120, because the recessed faces 120p between second portions 125 both face inwards. Therefore the innermost faces of the second portions are spaced further apart from one other, by virtue of the recesses formed by the canted portion 126 between the two end portions 121, 125 of the arms 120. Therefore, the spreader in the first configuration can accommodate large flanges between the second portions of the arms.

With reference to Figure 3, the same spreader 110 is shown with the arms 120a, 120b attached to the body 130 in a second alternative configuration, with respective arms 1 20a, 1 20b located onto the ends 1 30a, 1 30b of the cross members 1 30x in the opposite orientation (arms rotated 180°) to that of Figure 2. In the second configuration both of the relatively flatter (second) faces 1 20q of the arms face inwards, such that a second, narrower across-gap width 120k is presented between the arms 1 20a, 1 20b. In this way, by providing the flange spreader with arms that provide for two different across-gap widths, the spreader can be applied effectively to pipe flanges of different thicknesses, without compromising its integrity from bending moments imparted to the pin 140.

In certain circumstances, the arms 120 can be used facing the same way on the body 130 (e.g. by rotating just one of the arms by 180° from the configuration of Figure 2 or Figure 3), instead of facing in opposite directions, providing, in the same embodiment, an across-gap width intermediate the first and second configurations shown in the drawings.

The second portions 125 of the arms 120 can optionally each have two pin holes 128 and 129. The pin holes 128 and 129 have different diameters adapted to accommodate different diameters of pin 140. For example, as is best shown in Figs 4 and 5, the wide diameter pin 140' is accommodated in large diameter hole 128 and the narrow diameter pin 140" is accommodated in the narrower diameter pin hole 129. The large diameter pin holes in each of the arms can be arranged to align with one another when the arms 120 are attached to the body 130 in the first configuration, for accommodating a pair of large diameter heavy duty flanges in the gap between the arms, requiring a commensurately large pin to fill the bolt holes as much as possible, for example to help avoid excessive bending forces. The narrow diameter pin holes 129 in each of the arms can be arranged to align with one another when the arms are in the second configuration, for accommodating a narrower pair of lighter duty flanges in the gap between the arms, requiring a smaller pin to fill the bolt holes as much as possible. Optionally the arms 120 are arranged so that reversing the configuration of the arms on the body automatically permits only one of the two configurations -e.g. either large gap, with large diameter pin holes aligned, or small gap, with smaller diameter pin holes aligned. Typically the same connection interface between the arms and the body can be used for the two different configurations.

Various modifications and improvements may be made within the scope of the invention herein described. In particular, it will be appreciated that instead of using arms that are interchangeably mounted to present different gap widths, the arms could alternatively be fixed to the main body but may have an alternative surface structure to create different gap widths between the arms by different regions of surfaces either side of the gap. Alternatively, the spreader tool may be provided with inserts to narrow the gap.

Claims

CLAIMS1. A flange spreader comprising: -a pair of support arms adapted to be connected to a pair of opposed flanges; -a body connecting the support arms so that they are spaced apart from one another by a gap; -a separating device mounted between the arms and movable relative to the body for driving apart the opposed flanges; -wherein the support arms are adapted to retain a connector device for connecting the arms to the flanges; wherein the pair of arms are adapted to present a first gap width between the arms and a second gap width between the arms different from the first gap width.
2. A flange spreader as claimed in claim 1, wherein the support arms are adapted to connect to the body so that they extend away from the body along axes that are generally perpendicular to the axis of the body.
3. A flange spreader as claimed in claim 1 or claim 2, wherein the support arms are connectable to the body in different orientations to define different assembled configurations of the flange spreader, wherein in a first assembled configuration the arms define the first gap width and in a second assembled configuration the arms define the second gap width.
4. A flange spreader as claimed in claim 3, wherein the support arms are connectable to the body in different rotational positions about their respective axes and are non-symmetrical about their axes such that connection of the arms in different rotational positions thereby define different assembled configurations of the spreader and different gap widths between the arms.
5. A flange spreader as claimed in claim 3 or claim 4, wherein the arms are coupled in a first configuration facing one way on the body to define the first gap width therebetween, and in a second configuration facing an opposite way on the body to define the second gap width therebetween.
6. A flange spreader as claimed in any of claims 3 to 5, wherein the body has connecting portions for detachable connection of the arms thereto, and the arms are connected to the same connecting portion in the different assembled configurations of the spreader.
7. A flange spreader as claimed in claim 6, wherein the connecting portions are cylindrical and the support arms have sleeves for accommodating a cylindrical connecting portion of the body for connection thereto.
8. A flange spreader as claimed in claim 7, wherein the same sleeves of the support arms accommodate the cylindrical portions of the body in the different configurations of the spreader, so that the connection between the arms and the body is the same in the different configurations.
9. A flange spreader as claimed in any of claims 6 to 8, wherein the support arms are connectable interchangeably to different connecting portions of the body.
10. A flange spreader as claimed in any preceding claim, wherein the connector device is a single pin that spans across the gap between the arms, and is adapted to pass through bolt holes in the adjacent flanges.
11. A flange spreader as claimed in claim 10, wherein the pair of support arms is configured to hold a pin spanning across the first gap width for connecting the arms to opposed flanges of a first pipe flange thickness, and to hold a pin spanning across the second gap width for connecting the arms to opposed flanges of a second, different pipe flange thickness.
12. A flange spreader as claimed in claim 10 or claim 11, wherein the pin is adapted to allow the pin to pass through the flange bolt holes, and allow sliding of the flanges with respect to the pin, as the flanges separate relative to the stationary pin in use.
13. A flange spreader as claimed in any preceding claim, wherein the arms are adapted to retain the connector device at ends of the arms distal to the body.
14. A flange spreader as claimed in claim 13, wherein the arms are adapted at their distal ends to retain a first pin of a first diameter for connecting the arms to bolt holes of the opposed flanges and a second pin of a second diameter for connecting the arms to different bolt holes.
15. A flange spreader as claimed in any preceding claim, wherein the arms are non-symmetrical, and have non-symmetrical faces.
16. A flange spreader as claimed in any preceding claim, wherein the arms are identical to one another.
17. A flange spreader as claimed in any preceding claim, wherein the arms have recessed portions on at least one face.
18. A flange spreader as claimed in claim 17, wherein the arms have one generally flat face and one recessed face.
19. A flange spreader as claimed in claim 18, wherein the arms define three different configurations of the spreader: a first configuration in which the flat faces of the arms face one another, a second configuration in which the recessed portions of the arms face one another, and a third configuration in which the recessed portion of one arm faces the flat face of the other.
20. A flange spreader as claimed in any preceding claim, wherein the arms are non-identical to one another.
21. A flange spreader as claimed in claim 20, wherein the arms have recessed portions on at least one face and the recessed portions have different dimensions between different arms.
22. A flange spreader as claimed in claim 20 or claim 21, wherein the arms incorporate a step, so that the connection between the arms and the body lies in a different plane than the connection between the arms and the connector device.
23. A flange spreader as claimed in claim 22, wherein the arms have an extended S-shape with a first end that is generally disposed in one plane and a second end that is spaced apart from the first end and lies in a different plane that is generally parallel to the plane of the first end.
24. A flange spreader as claimed in claim 23, wherein the spacing between the two planes is adjusted according to the required dimensions and strength of the spreader.
25. A flange spreader as claimed in claim 23 or claim 24, wherein the spacing between the two planes is the same between arms.
26. A flange spreader as claimed in any preceding claim, wherein the separating device is a wedge device mounted in a cylinder on the body.
27. A flange spreader as claimed in any claim 26, wherein the wedge device is driven by a screw thread mechanism.
28. A flange spreader as claimed in claim 26, wherein the wedge device is actuated by a fluid actuation cylinder.
29. A flange spreader as claimed in any preceding claim, wherein the body is adapted to withstand reaction forces from driving the separating device between the flanges.
30. A flange spreader as claimed in any preceding claim, wherein the body is adapted to guide movement of the separating device along an axis aligned with a plane separating the opposed flanges.
31. A wedge member for a flange spreader, the wedge member having an axis, and having first and second surfaces that are inclined relative to the axis of the wedge member for separating the flanges of a pipe, wherein the first and second surfaces are arranged at different angles with respect to one another.
32. A wedge member as claimed in claim 31, wherein the wedge member is symmetrical about its axis, and has a pair of first angled surfaces, set at the same (but opposite) angle with respect to the axis of the wedge member, and a pair of second angled surfaces set at the same (but opposite) angle with respect to the axis of the wedge member.
33. A wedge member as claimed in claim 31 or claim 32, wherein the first surface(s) are set at a steeper angle with respect to the wedge member than the second surface(s).
34. A wedge member as claimed in any of claims 31 to 33, wherein the wedge member tapers toward an apex and the second surface(s) is closer to the apex than the first surface(s).
35. A wedge member as claimed in claim 34 when dependent on claim 32, wherein the first surfaces are arranged at the same distance from the apex, and at opposite sides of the wedge member.
36. A wedge member as claimed in claim 34 when dependent on claim 32, or as claimed in claim 35, wherein the second surfaces are arranged at the same distance from the apex and are arranged on opposite sides of the wedge member.
37. A wedge member as claimed in any of claims 34 to 36, wherein the apex of the wedge member has a recess that extends parallel to the axis of the wedge member.