Note: Descriptions are shown in the official language in which they were submitted.
WO 2011/120959 PCT/EP2011/054806
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An actuator device
The present invention relates to a device for use in connection with oil
and/or gas
wells onshore or offshore.
In connection with various types of work and operations carried out during
drilling,
completion, start-up and operation of an oil and/or gas well onshore or
offshore,
equipment and tools are employed which are controlled or operated
electrically,
hydraulically, by means of pressure, etc.
A plurality of units in a well, for example valves such as gas lift valves,
are
controlled by the pressure to which they are exposed, and are therefore
designed to
be opened or closed within specific pressure ranges. However, if a sudden rise
or
drop in pressure occurs in the well, these gas lift valves could be opened or
closed
inadvertently on account of their predetermined range of operation. As a
result,
undesirable and dangerous situations could arise. Equipment and tools in a
well
could be inadvertently activated/deactivated, thereby causing undesirable and
potentially dangerous situations to arise.
An object of the present invention is to provide a device which can be
activated or
deactivated in a safe and controlled manner by pressure differences in a fluid
in a
well.
This object is achieved by a device as indicated in the following independent
claim,
where further features of the invention will become evident from the dependent
claims and the description below.
It should be understood, however, that the device according to the present
invention
may also have other areas of application than down in a well, for example in
connection with processing equipment which may be located on the seabed or
also
topsides or on shore.
According to the invention a device is provided, particularly suitable for use
in an
oil and/or gas well. The device comprises an external structure and a pressure-
influenced bellows, where this bellows comprises a first and second bellows
device
in fluid communication with each other, where the first and second bellows
devices
are arranged relatively to the external structure in such a manner that during
use
they can experience different pressure influence. This may be adapted in
several
ways, where the one bellows device is located in a space which is separated
from
the space in which the other bellows device is located, thereby enabling them
to be
influenced pressure-wise by different external fluids. That the bellows
devices are
in fluid communication means that a change in pressure influence on one
bellows
device is transmitted to the other bellows device via the fluid
communications.
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According to the invention the external structure comprises a through-going
bore
and the pressure-influenced bellows is mounted at least partly in an annulus
arranged round the through-going bore. The annulus is at least partly composed
of
the external structure. One of the bellows devices is connected to a device
for
activation of a unit. By this one obtains that a large area of a bellows is
subjected to
a pressure change and thereby obtain a more reliable activation of pressure-
activated units in a well.
According to an aspect of the invention, the unit to which the bellows is
connected
may be a valve device. This valve device may be mounted in the through-going
bore
in the external structure for opening and closing the through-going bore. The
connection between the bellows and the valve device may be arranged so as to
enable the valve device to be activated between an open and a closed position
on
movement of the bellows as a consequence of pressure influence on the bellows.
In
a possible embodiment there may also be locking devices which are released,
thereby releasing for example a valve device from a first position to an
operational
position where the valve device as such can now be controlled by pressure
variations in the ambient fluid. By allowing the device according to the
invention to
be able to be operated at a high pressure, whereby it opens a valve device in
the
through-going bore, it can act as a locking device for a second pressure-
activated
valve device. This second pressure-activated valve device is thereby prevented
from
being activated before the device according to the invention is activated,
whereby a
more reliable activation of pressure-activated units in the well is achieved.
According to another aspect the bellows devices may be arranged relatively
outside
the through-going bore in the external structure. This means that the through-
going
bore can be designed without constrictions as a result of the bellows device.
The
through-going bore can therefore have the desired diameter, either fixed or
varying,
through the device. This can be achieved by the annulus in which the bellows
is
mounted being, for example, arranged internally in the external structure.
This
annulus may have at least one opening or a plurality of openings to the
through-
going bore round the circumference of the through-going opening.
Alternatively, the
bellows devices may be mounted at least partly internally in the through-going
bore
in the external structure. In a variant there may be a recess in the wall of
the
through-going bore and a sleeve element provided internally in the bore,
thereby
forming an annulus between them. Alternatively, a sleeve may be provided
internally in the bore in the external structure, at a distance therefrom, so
that the
annulus is formed between these, where the annulus is closed at one end, where
the
sleeve, the structure and the bellows are configured in such a manner that one
of the
bellows devices is mounted in a closed space formed inside this annulus and is
therefore not influenced by the fluid located in the through-going opening.
The
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sleeve is connected in a suitable fashion to the external structure, for
example by
welding, threaded connection or the like.
According to an aspect of the invention, both the first and second bellows
device
may be arranged in the annulus formed between the sleeve and the external
structure. Alternatively, one of the bellows devices may be arranged in the
annulus
formed round the through-going bore, while the other bellows device is
arranged at
the side of this annulus.
According to an aspect of the invention, at least one of the bellows devices
of the
bellows may be formed with an annular structure. In a variant at least one of
the
bellows devices may then form a closed ring and in another variant this ring
may
not be completely closed. This annular structure is thus complementary to the
annulus. Alternatively, both the bellows devices may have an annular structure
and
be mounted in the annulus. The annulus will then be divided into two separate
chambers with one bellows device in one chamber and the other bellows device
in
the other chamber. In such an embodiment at least one of the chambers may be
open
to the through-going bore.
In an alternative embodiment of the present invention, the first and second
pressure-
influenced bellows devices may cover only a part of the circumference of the
annulus. The first and second pressure-influenced bellows devices may be
composed of a number of separate, isolated bellows devices, where these are
arranged at a distance from one another round the circumference of the
annulus. For
example, four separate, isolated pressure-influenced bellows devices may be
mounted in the annulus, where these are arranged in twos diametrically above
one
another. In yet another alternative embodiment of the present invention one
pressure-influenced bellows device may be designed to extend round the whole
circumference of the annulus, while the other pressure-influenced bellows
device
may be composed of a number of separate, isolated bellows devices.
Depending on the configuration of the external structure and the annulus, the
arrangement of the first and second pressure-influenced bellows devices in the
annulus may cause one or both of the first and/or second pressure-influenced
bellows devices to be subjected to the influence of a fluid located in the
through-
going bore in the external structure. In an alternative embodiment one
pressure-
influenced bellows device may in addition also be influenced by an activation
device, or only by an activation device where the activation device may be
controlled electrically, mechanically, electromagnetically, etc.
When viewed in a section in its longitudinal direction which in this case is
substantially parallel to the through-going bore, such a pressure-influenced
bellows
device may have a shape which may be oval, polygonal, curved, but preferably
not
circular, with the result that compression or extension of the bellows device
may
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easily be achieved. A compression or an extension of a pressure-influenced
bellows
device is obtained by the bellows device being subjected to an external
influence,
where this external influence may, for example, be a pressure, a mechanical
influence or the like. According to an embodiment of the present invention the
pressure-influenced bellows devices are made of a number of sections or disks,
which are assembled to form the pressure-influenced bellows device. The
different
sections or disks will then be glued, welded or joined together in another
suitable
way. The pressure-influenced bellows devices may also be envisaged
manufactured
by machining, casting etc. The pressure-influenced bellows devices are
preferably
made of a metallic material, but they may also be made of a non-metallic
material
or an elastomeric material. It is also possible for a pressure-influenced
bellows
device to be made of several different materials.
According to an aspect of the invention, the first and second bellows devices
may
be in fluid connection with each other via a support device, said support
device
forming a transverse wall in the annulus. Transverse wall in this context
should be
understood to refer to a wall which extends in a radial direction, forming a
ring
surface. Furthermore, this transverse wall will also divide the annulus into
two
annular chambers. The two annular chambers are then arranged behind each other
along an axis of the through-going bore. The support device is connected in a
suitable fashion to the inside of the external structure's through-going bore
and the
outside of the sleeve where a sleeve is provided internally in the through-
going
bore.
According to an aspect, the first and second pressure-influenced bellows
devices
and the support device may be filled with an incompressible fluid. As the
pressure-
influenced bellows devices shall contain a fluid, preferably an incompressible
fluid,
they will either be closed at their ends or be designed so that they can be
connected
to the support device, thereby forming a closed volume internally in the unit
composed of the pressure-influenced bellows devices and the support device.
How
this connection is carried out and the design of the support device will be
explained
later.
Furthermore, the first and second pressure-influenced bellows devices may be
designed with substantially the same shape and volume. Alternatively, the
first and
second pressure-influenced bellows devices may be designed with substantially
the
same shape, but with different volume. In yet another alternative the first
and
second pressure-influenced bellows devices may be designed with different
shape
and volume. When one bellows device is influenced by pressure and compressed,
a
volume of fluid will be displaced from this bellows device over to the other
bellows
device which will be extended in order to make room for the volume displaced
from
the first bellows device. The length of the compression and/or extension
depends on
the shape and volume of the respective bellows devices. The bellows devices
may
WO 2011/120959 PCT/EP2011/054806
be arranged to have corresponding lengths or there may be ratios between the
bellows devices and compression/extension.
In an embodiment the present invention may be regarded as a pressure-
controlled
actuator, where the pressure-controlled actuator comprises an external
structure and
5 a pressure-influenced bellows.
The external structure is provided with a through-going bore, where the
bellows are
mounted in an annulus in connection with the through-going bore.
As the device or the pressure-controlled actuator should be capable of being
connected to equipment and/or tools, one or both ends of the actuator's
external
structure may be designed to be able to be connected or coupled in a fluid-
tight
manner to the said equipment and/or tools. The external structure's end(s)
(external
circumference) may then be provided with a threaded portion, a flange for a
bolt or
screw connection, include rapid couplings etc., thereby enabling the pressure-
controlled actuator to be connected via one end, for example to a gas lift
valve
mounted in a production tubing, and with a pressure pipe connected to one of
the
bellows devices, where the pressure pipe is used for activating/deactivating
the
pressure-controlled actuator. The pressure-controlled actuator's external
structure
may be manufactured in a single piece, or it may be composed of several
component
elements, which together form the external structure.
In an embodiment of the present invention, when it is mounted in the external
structure, the first pressure-influenced bellows device may only be supported
by the
support device, while the second pressure-influenced bellows device will be
supported by the support device at one end and at the opposite end by a sleeve
which is axially movable in the external structure.
In one embodiment, the annulus may have an axial length and a radial dimension
(width), where the bellows which are mounted in this annulus will have a width
which is less than the "width" of the annulus, when viewed in the same
direction as
the through-going bore. This means that when they are influenced, the first
and
second pressure-influenced bellows devices can move "freely" in the axial
direction
of the external structure, thereby permitting them to be extended/compressed
in
their axial directions. The bellows device is furthermore configured in such a
manner that all volume change takes place on extension/compression in the
axial
direction. The first and second pressure-influenced bellows devices are
furthermore
"hydraulically" connected to each other via the support device, with the
result that
the pressure-influenced bellows devices will mutually influence each other in
their
axial direction. If, for example, the first pressure-influenced bellows device
is
influenced so that it is compressed, the compression will be "transmitted" via
the
support device, with the result that the second pressure-influenced bellows
device is
extended by a certain length.
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In a similar manner an influence on the second pressure-influenced bellows
device
will cause the first pressure-influenced device to be extended or compressed,
depending on whether the second pressure-influenced bellows device was
compressed or extended. The incompressible fluid will then be "transmitted"
from
one pressure-influenced bellows device to the other, whereby in an embodiment
it
will be possible to control and monitor the opening and closing of the
pressure-
controlled actuator by means of this "transmission" of fluid between the
pressure-
influenced bellows devices.
In an embodiment of the invention the support device is securely connected in
a
suitable manner to the walls of the annulus. This may be implemented, for
example,
by welding, gluing, screwing etc. Since the support device has a radial
dimension
(width) which substantially corresponds to the width of the annulus, the
support
device and walls of the annulus including an end wall of the annulus will form
a
fluid-tight space, in which fluid-tight space one of the pressure-influenced
bellows
devices is mounted. In an alternative embodiment, therefore, this fluid-tight
space
may be influenced by a pressure fluid controlled from a remote location, or a
pressure set when the device was assembled. In this fluid-tight space,
however, an
elastic element surrounding the first pressure-influenced bellows device may
also be
mounted, for example a nitrogen package, one or more springs etc., where these
will
be capable of creating a "pre-tensioning" or bias against the pressure-
influenced
bellows device.
According to an embodiment of the invention the support device is in the form
of a
hollow, closed cylinder, where a through-going hole or opening is provided in
the
closed cylinder's top and bottom surface, when viewed in the cylinder's
longitudinal direction. The first and second pressure-influenced bellows
devices are
then connected via their open end with the holes in the support device's top
and
bottom surface, with the result that the first and second pressure-influenced
bellows
devices together with the support device form a closed, fluid-tight unit. It
should be
understood, however, that the support device may also have other shapes.
According to an embodiment of the present invention a "floating" piston may be
provided internally in the support device, where the piston is permitted to be
moved
in the support device's axial direction when one or both of the pressure-
influenced
bellows devices are subjected to an external influence. The piston has a
radial
dimension (diameter) which is substantially the same radial dimension as the
support device's internal surface (circumference). When the piston comes into
contact with the support device's top or bottom surface, the piston will not
move
further, thereby causing the movement of the pressure-influenced bellows
devices to
also be stopped.
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In another embodiment of the present invention a delay device may be provided
in
the support device, where this delay device is intended to delay the flow of
the
incompressible fluid through the support device. In its simplest form this
delay
device may comprise a plate provided with one or more through-going holes. The
plate is attached internally in the support device in a suitable fashion.
Since the object of the present invention is to provide a device which
operates
within a predefined pressure range, the pressure-influenced bellows devices
may be
mounted in the annulus in such a manner that the support device in itself
forms a
delimitation (end stop) for the movement the first and the second pressure-
influenced bellows devices respectively are permitted to perform. This means
that if
the first pressure-influenced bellows device is subjected to a pressure which
causes
the first pressure-influenced bellows device to be compressed in its axial
direction,
the support device, which acts as an end stop, will prevent a further
extension of the
second pressure-influenced bellows device from occurring. Correspondingly,
when
the pressure round it is increased, the second pressure-influenced bellows
device
will be permitted only a certain amount of travel in its axial direction
before the
second pressure-influenced bellows device's movement is stopped by the support
device, whereby the first pressure-influenced bellows device is also prevented
from
being further extended.
In an alternative embodiment an end stop may be composed of a sleeve which is
preferably provided on the inside of the support device, in which case the
sleeve
will extend through the through-going hole in the support device's top and/or
bottom surface and continue for a length into the pressure-influenced bellows
device's axial direction. Such an end stop, in the form of a sleeve, may then
be
provided on each side of the support device, or only on one side.
It should also be understood that the sleeve forming the end stop may be
arranged
externally of the pressure-influenced bellows device or devices. In this case
the
sleeve will be connected in a suitable manner with the support device's top
and/or
bottom surface. The pressure-influenced bellows devices may then be provided
with
a radially extending flange at the end opposite the support device, where the
flange
is brought into abutment with the sleeve when the pressure-influenced bellows
device is compressed by a certain length. A further compression of the
pressure-
influenced bellows device will therefore not be possible.
The end stop may also be composed of a flange or the like mounted in the
actual
annulus.
With regard to the above it should be noted that the travel permitted for the
first
and/or second pressure-influenced bellows device will be dependent on a number
of
parameters, for example the well conditions, the type of work and/or operation
that
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has to be conducted, size of the tubing etc., where a person skilled in the
art will
know how this should be done.
In an embodiment of the present invention one or both of the pressure-
influenced
bellows devices may be designed so that when a desired compression of the
pressure-influenced bellows device is achieved, the pressure-influenced
bellows
device will be substantially compressed, with the result that a further
compression
of the pressure-influenced bellows device cannot be achieved. This means that
in its
maximum compressed position, the pressure-influenced bellows device will
behave
like a solid, compact element, thereby giving the pressure-influenced bellows
device great mechanical strength and pressure resistance.
Due to the fact that the fluid-tight space in which the first pressure-
influenced
bellows device is located is supplied with a fluid and subsequently
pressurised at a
specific pressure, where this causes the first pressure-influenced bellows
device to
be subjected to a preset pressure, the first pressure-influenced bellows
device will
be influenced by this preset pressure and compressed against the support
device.
The first pressure-influenced bellows device will then be able to be
completely
compressed, i.e. it assumes the position of a solid, compact element, which
cannot
be further compressed. This compression of the first pressure-influenced
bellows
device will then cause the second pressure-influenced bellows device to be
extended
for a length, with the result that the second pressure-influenced bellows
device,
which in an embodiment is connected to the movable sleeve, will permit a
damper
to rotate out to abut with one or more "seats" in the external structure's
bore,
thereby causing the damper to shut off the longitudinal bore in the external
structure. Where the second pressure-influenced bellows device is connected to
a
flap, the flap will be pushed out of the stationary sleeve, whereby, on
account of its
properties, the flap will be bent or curved in order thereby to close the
longitudinal
bore in the external structure.
The transmission of the axial movement between the first and the second
pressure-
influenced bellows device, however, may also be carried out in other ways than
the
first pressure-influenced bellows device being subjected to a fluid pressure,
for
example by means of a transmission mechanism. The transmission mechanism may,
for example, be a slide valve, a rack transmission or the like which is
attached
internally in the external structure's bore and connected in a suitable manner
to the
first pressure-influenced bellows device. By influencing the transmission
mechanism, this influence will be transmitted to the first pressure-influenced
bellows device. The transmission mechanism may furthermore be capable of being
influenced hydraulically, electro-hydraulically, electrically,
electromagnetically,
magnetically etc.
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In an embodiment of the present invention the first and/or the second pressure-
influenced bellows device may be designed to be capable of being filled with
or
drained of the fluid it contains, thereby enabling the pressure and/or the
fluid it
contains to be varied/replaced.
Other advantages and special features of the present invention will become
clear
from the following detailed description, the attached figures and the
following
claims.
The invention will now be described in greater detail with reference to the
following figures, in which:
Figure 1 illustrates a first embodiment of a device according to the present
invention,
Figure 2 illustrates a second embodiment of a device according to the present
invention, and
Figure 3 illustrates a third embodiment of a device according to the present
invention.
Figure 1 illustrates an embodiment of a device according to the present
invention,
where the device comprises an external structure 1, such as the cylindrical
wall of a
pipe or similar. In the illustrated embodiment, the external structure 1 is
designed in
a single piece. It may also be envisaged, however, that the external structure
1 is
composed of several elements, which when assembled form the external structure
1.
The external structure 1 is provided with a through-going bore 2, with the
result that
the external structure 1 is open at its ends. Internally in the through-going
bore 2
there is further provided a sleeve 3, said sleeve 3, which is stationary,
having an
external diameter which is less than the through-going bore's 2 internal
diameter.
This will result in the formation of an annulus between the wall of the
external
structure 1 and the stationary sleeve 3. The stationary sleeve 3 is attached
in a
suitable manner to the external structure 1, internally therein. Furthermore,
the
annulus which is delimited by the through-going bore 2 in the external
structure 1
and the stationary sleeve's 3 external diameter will be closed at one end of
the
external structure 1/the stationary sleeve 3 by a plate 4. At its opposite end
the
external structure 1/the stationary sleeve 3 will be open.
Internally in the annulus which is delimited by the through-going bore 2 and
the
stationary sleeve 3, a support device 5 is provided, which support device 5 is
securely connected to the external structure 1 and the stationary sleeve 3.
Two
pressure-influenced bellows devices, the first pressure-influenced bellows
device 6
and the second pressure-influenced bellows device 7 are furthermore connected
to
the support device 5.
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The first and second pressure-influenced bellows devices 6, 7 are provided as
a
bellows, having a shape resembling an accordion bellows, where a plurality of
sections or disks 8 are assembled to form the actual bellows. This may be
implemented, for example, by welding, gluing or by interconnecting the
sections or
5 disks 8 in another suitable manner.
The two pressure-influenced bellows devices 6, 7 are interconnected via the
support
device 5. The outermost section or disk 8 (i.e. an end section) in one end of
the
pressure-influenced bellows device 6, 7 is then welded, glued or connected in
another suitable manner to each side of the support device 5. The pressure-
10 influenced bellows devices 6, 7 are closed at their other end. For its part
the support
device 5 is connected with the inside of the bore 2 and the sleeve's 3 outer
surface.
This may be implemented, for example, by welding, gluing, screwing or in
another
suitable fashion.
The design of the actual support device 5 will be explained later.
In a similar manner to the first pressure-influenced bellows device 6, the
second
pressure-influenced bellows device 7 is closed at its other end (i.e. the end
which is
opposite the connection with the support device 5) and in addition connected
to a
flap mechanism 9 unit.
Since the support device 5 is securely connected to the inside of the through-
going
bore 2 and the outer surface of the stationary sleeve 3, the support device 5
will
form a fluid-tight partition internally in the external structure between the
first and
second pressure-influenced bellows devices 6, 7. This results in the formation
of a
closed space 10, which closed space 10 encloses the first pressure-influenced
bellows device 6. This closed space 10 is filled with a fluid, for example
nitrogen
under pressure, with the result that the first pressure-influenced bellows
device 6 is
subjected to a desired "pre-tensioning" or bias. Depending on its magnitude,
this
pre-tensioning will influence the first pressure-influenced bellows device 6,
causing
it to be compressed. The closed space 10 is filled by arranging a through-
going hole
(not shown) in the external structure 1, to which hole a non-return valve for
example is attached.
It may, however, also be conceivable that the first pressure-influenced
bellows
device 6 may be influenced by an activation mechanism 11, with the result that
the
closed space 10 does not have to have a preset pressure. In this case the
activation
mechanism 11 may be designed so as to transmit or apply a force to the first
pressure-influenced device 6, causing it to be compressed or extended in its
axial
direction. The activation mechanism 11 may, for example, be designed so as to
be
activated electrically, hydraulically, magnetically, electromagnetically etc.
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In a similar manner a space 12 will also be formed round the second pressure-
influenced bellows device 7, which space 12 is formed by the support device 5,
the
through-going bore 1 in the external structure 1 and the stationary sleeve 3.
The
space 12 will be open at the end opposite the support device 5. The second
pressure-
influenced bellows device 7 will then also be subjected to an external
influence, for
example from a pressure inherent in a fluid in the well's annulus.
Each of the pressure-influenced bellows devices 6, 7 is hollow in form and
contains
an incompressible fluid, and the pressure-influenced bellows devices 6, 7
therefore
must be designed as a closed unit. This may be achieved in several different
ways,
for example by one end of the pressure-influenced devices 6, 7 being connected
to
the support device 5, while their opposite end is delimited by an end surface
(not
shown).
The support device 5 according to figure 1 is in the form of a closed
cylinder, where
a through-going hole (not shown) is provided in the material of the closed
cylinder's top and bottom surface. The first and second pressure-influenced
bellow
devices' 6, 7 open end (i.e. the end opposite the end surface) is then
connected to
this through-going hole, thereby forming a closed unit, consisting of the
first
pressure-influenced bellows device 6, the intermediate support device 5 and
the
second pressure-influenced bellows device 7.
A movable piston 13 is further mounted internally in the support device 5,
where
this piston 13 is permitted to be moved in the support device's 5 axial
direction. The
piston 13, moreover, may be designed in such a manner that together with the
through-going hole in the support device's 5 top and/or bottom surface, it
forms a
metal-to-metal seal, with the result that when the piston 13 is brought into
contact
with the support device's 5 top or bottom surface, the first or the second
pressure-
influenced bellows device 6, 7 will not be permitted a further movement in its
axial
longitudinal direction. The device will be able to function without this
movable
piston internally in the support device.
In the support device 5 a delay device 14 may also be provided, where this
delay
device 14 is intended to delay the flow of the incompressible fluid in the
support
device 5. In its simplest form the delay device 14 comprises a plate provided
with
one or more through-going holes (not shown). The delay device 14 is mounted in
a
suitable manner in the support device 5. The device will be able to function
without
this delay device.
In figure 1 the first pressure-influenced bellows device 6 is connected to an
activation mechanism 11, which is composed of a rack transmission or a slide
valve.
By means of an external influence of the first and/or second pressure-
influenced
bellows device 6, 7, they will be able to be controlled so that the flap
mechanism 9,
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which is connected to the second pressure-influenced bellows device 7, will be
able
to be pushed into the space 12, in order thereby to open up through-flow
through the
device, or out of the space 12, in order thereby to shut off through-flow
through the
device.
Figure 2 illustrates a second embodiment of the device according to the
present
invention, where the external structure 1 is provided with a through-going
bore 2,
with the result that the external structure 1 is open at its ends. Internally
in the bore
2, moreover, a stationary sleeve 3 is provided. The stationary sleeve 3 is
connected
in a suitable manner to the external structure 1. This results in the
formation of an
annulus, when viewed in a plane perpendicular to the external structure's 1
axial
longitudinal direction, between the through-going bore 2 and the stationary
sleeve
3. In this annulus a support device 5 is provided, where the support device 5
is
securely connected to the external structure 1 and the stationary sleeve 3.
Two
pressure-influenced bellows devices, the first pressure-influenced bellows
device 6
and the second pressure-influenced bellows device 7, are furthermore connected
to
the support device 5 via one end.
The design of the first and second pressure-influenced bellows devices 6, 7
corresponds to what has been described above (the version according to figure
1)
and therefore no further explanation thereof will be given here.
The pressure-influenced bellows devices' 6, 7 one end surface 15 (i.e. the end
surface opposite the connection to the support device 5) will therefore be
subjected
to an external influence, for example from a fluid located in the external
structure's
1 through-going bore 2.
The second pressure-influenced bellows device 7 will furthermore be connected
in a
suitable manner to a unit which in this case is a movable sleeve 16, where
this
movable sleeve 16 will follow the second pressure-influenced bellows device's
movement. The movable sleeve 16 will furthermore be arranged outside and
partly
overlapping the stationary sleeve 3, thereby forming a space between the
stationary
and the movable sleeves 3, 16. In this space is mounted a closing mechanism 9
(for
example in the form of a damper) for the device, which closing mechanism 9 is
permitted to rotate about its suspension point 17. This means that in an open
position of the device (the closing mechanism's 9 retracted position), the
closing
mechanism 9 is "stored" in the space between the stationary and the movable
sleeves 3, 16, thereby permitting a fluid to flow through the device, and in a
closed
position of the device (the closing mechanism's 9 extended position) it is
brought
into abutment with seat 18, in order thereby to close the device in a fluid-
tight
manner.
By means of an external influence of the first and/or second pressure-
influenced
bellows devices 6, 7, they will be able to be controlled in such a manner that
the
WO 2011/120959 PCT/EP2011/054806
13
closing mechanism 9 will be able to be brought from an open to a closed
position
and vice versa, in order thereby to close or open the device.
Figure 3 illustrates yet another embodiment of the device according to the
present
invention, where the closing mechanism is now composed of a ball valve 19. The
ball valve 19 is provided with a through-going hole (only roughly
illustrated),
where the through-going hole will extend parallel to the external structure's
longitudinal bore 2 in an open position of the device. When the pressure-
influence
bellows devices 6, 7 are influenced, on account of its connection with the
second
pressure-influenced bellows device 7, the ball valve 19 will be rotated 90
degrees
relative to its open position, whereby the ball valve 19 will shut off a
through-flow
of fluid through the device. The pressure-influenced bellows devices' 6, 7
mode of
operation will be as described for the other embodiments.
Only elements related to the invention have been explained and described in
the
above and a person skilled in the art will understand that the external
structure may
be designed as a unit or it may be composed of several elements which are
interconnected. The device may furthermore have suitable devices for
interconnection or mounting in a process fluid flow. A person skilled in the
art will
furthermore appreciate that several versions and modifications of the
described and
illustrated embodiments may be provided within the scope of the invention as
defined in the attached claims.
