WO1990003489A1

WO1990003489A1 - A valve assembly to co-operate with a readily removable valve actuator

Info

Publication number: WO1990003489A1
Application number: PCT/GB1989/001108
Authority: WO
Inventors: Stephen Anthony Hatton; John Ernest Lawson
Original assignee: Mobil Oil Corporation; Fssl Limited; Cameron Offshore Engineering Limited
Priority date: 1988-09-22
Filing date: 1989-09-21
Publication date: 1990-04-05
Also published as: GB8822266D0

Abstract

A valve assembly, comprising a valve (10) and a valve operator (11), and, for example, to be mounted fixedly within a structure, and in particular a sub-sea structure, such as a submerged well-head, is adapted to be combined with a co-operating valve actuator (30), and/or to have a co-operating valve actuator replaced, by employing only remotely-controlled transporting and manipulative means. Thus, there is a first arrangement in which both the valve operator (11) is engaged with, but is detachable from, the piston stem (35), and the valve body (12) is engaged with, but is detachable from, the actuator housing (31), for example, by relative linear movement between the valve assembly and the actuator. In a second arrangement both the valve operator (11) is secured to the piston stem (35), and the valve body (12) is secured to the actuator housing (31), for example, by relative rotation between the valve assembly and the actuator, and from said first, to said second, arrangement. During such a securing action, or an opposite, releasing action, the valve operator (11) may be locked at a predetermined position, by means (25, 26, 27) which is undisturbed by attachment, and detachment, of the actuator, respectively, to, and from, the valve assembly.

Description

A VALVE ASSEMBLY TO CO-OPERATE WITH A READILY

REMOVABLE VALVE ACTUATOR

THIS INVENTION relates to a valve assembly, comprising a valve and a valve operator, adapted to co-operate with a readily removable valve actuator, and to a combination of such a valve assembly and a readily removable valve actuator, for example, the valve actuator being adapted to be attached to, or to be removed from, the valve assembly by remotely-controlled manipulative means, say, when the combination is subjected to a high pressure, such as being submerged at a depth under water which is hazardous for a diver, possibly the operating

environment for the combination being under the sea.

It is an object of the present invention to provide a novel and advantageous construction for a valve assembly, comprising a valve and a valve operator, and adapted to co-operate with a readily removable valve actuator, for example, the valve actuator to be attached to, or to be removed from, the valve assembly by remotely-controlled manipulative means.

It is another object of the present invention to provide a novel and advantageous construction for a combination of a valve assembly, comprising a valve and a valve operator, and a co-operating, readily removable, valve actuator, for example, the combination being adapted so that the valve actuator can be attached to, or can be removed from, the valve assembly by remotely-controlled manipulative means.

According to the present invention a valve assembly has a valve operator, and a valve including a valve stem slidably mounted, for movement along its longitudinal axis, in a valve body, with the valve stem arranged to move with the valve operator, in a known manner, the assembly being arranged to co-operate with a valve actuator, the valve actuator to comprise a fluid actuable piston slidably mounted, for movement along the longitudinal axis of its stem, in a chamber provided in an actuator housing, with the piston stem to extend from the actuator housing, and to be coaxial with the piston stem, the construction of the valve assembly being such, and the construction of the co-operating valve actuator to be such, that there is capable of being a first arrangement of the valve assembly and the co-operating valve actuator in which both the valve operator is engaged with, but is detachable from, the piston stem, and the valve body is engaged with, but is detachable from, the actuator housing, and there is capable of being a second arrangement of the valve assembly and the co-operating valve actuator in which both the valve operator is secured to the piston stem, and the valve body is secured to the actuator housing.

Thus, the valve actuator is readily attached to, and is removable from, the valve assembly, possibly by remotely- controlled manipulative means, for example, if the combination is located in a hazardous environment.

Usually the valve operator is secured to the valve stem.

Advantageously, the construction of the valve assembly is such, and the construction of the co-operating valve actuator is to be such, that both the valve operator is to be secured to the piston stem, and the valve body is to be secured to the actuator housing, solely by relative movement between the valve assembly and the valve actuator, and the arrangement is such that, at least during such a securing action, the valve operator is constrained to be movable only with the valve body. Such an arrangement facilitates the use of remotely-controlled

manipulative means in the attachment, and detachment, of the actuator, respectively, to and from, the valve assembly.

Conveniently, the construction of the valve assembly is such, and the construction of the co-operating valve actuator is to be such, that both the valve operator is to be secured to the piston stem and the valve body is to be secured to the actuator housing, by relative movement, for example, relative rotation, between the valve assembly and the valve actuator, and in which assembly there is provided releasable means to constrain the valve operator , the arrangement being such that , at leas t during such a securing action, the valve operator is releasably constrained to be movable only with the valve body. The valve body may be mounted fixedly within a structure, such as a well-head, connected to a hydrocarbon-extracting production line, the line being controlled by the valve. Irrespective of whether the valve body is mounted fixedly, or not, means may be provided to lock , in a re leasab le manner , the valve operator at a predetermined position within the valve body. Such locking means may include a member slidably displacable within the valve body, in a radial direction in relation to the longitudinal axis of the valve stem, and between a release position and a locking position. Possibly the displacement of the locking member, from the release position to the locking position, is caused by rotation of an eccentric rotatably mounted within the valve body.

According to another aspect the present invention comprises a combination including a valve assembly of any of the possible forms referred to above, and a co-operating valve actuator comprising a fluid actuable piston slidably mounted, for movement along the longitudinal axis of its stem, in a chamber provided in an actuator housing, with the piston stem extending from the actuator housing, and being coaxial with the piston stem, the constructions of the valve assembly and the co-operating valve actuator being such that, at least, there is capable of being a first arrangement of the valve assembly and the co-operating valve actuator in which both the valve operator is engaged with, but is detachable from, the piston stem, and the valve body is engaged with, but is detachable from, the actuator housing, and, at least, there is capable of being a second arrangement of the valve assembly and the co-operating valve actuator in which both the valve operator is secured to the piston stem, and the valve body is secured to the actuator housing.

Irrespective of whether, or not, the engagement, and the detachment, of the valve body and the actuator housing causes, respectively, the engagement, and the detachment, of the valve operator and the piston stem, and the securing of the valve body to the actuator housing causes the securing of the valve operator to the piston stem, the constructions of the valve assembly, and the co-operating valve actuator, may be such that the valve body is secured to the actuator housing by relative movement, for example, relative rotation, therebetween, and/or, the valve operator is secured to the piston stem by relative movement, for example, relative rotation, therebetween.

The constructions of the valve assembly, and the co-operating valve actuator, may be such that both the valve operator is secured to the piston stem, and the valve body is secured to the actuator housing, by relative movement between the valve assembly and the valve actuator, and the arrangement is such that, at least during such a securing action, the piston stem is constrained to be movable only with the actuator housing in the securing action. If the valve operator is constrained to be movable only with the valve body in the securing action, the piston stem may be arranged to be constrained in the required manner, during the securing action, by engagement with the valve operator.

As stated above, in relation to the valve assembly, and, hence, in accordance with the present invention, also in relation to the combination, constructions of the valve assembly, and the co-operating valve actuator, are required to be such that there is a first arrangement of the valve assembly and the co-operating valve actuator, in which both the valve operator is engaged with, but is detachable from, the piston stem, and the valve body is engaged with, but is detachable from, the actuator housing, and there is a second arrangement of the valve assembly and the co-operating valve actuator, in which both the valve operator is secured to the piston stem, and the valve body is secured to the actuator housing. Further, in relation to the combination, a change between said first arrangement and said second arrangement may be caused by relative movement, for example, relative rotation, in one direction, between the valve assembly and the co-operating valve actuator. With the valve actuator secured to the valve assembly, there is allowed relative movement between the valve assembly and the co-operating valve actuator, in the reverse direction, to cause a change from said second arrangement to said first arrangement. Usually, when a change between said first arrangement, and said second arrangement, is caused by relative movement between the valve assembly and the co-operating valve actuator, such a relative movement therebetween is different in form from the relative movement therebetween, which, with the valve assembly and the co-operating valve actuator in said, first arrangement, is to cause both the piston stem to be detached from the valve operator, and the actuator housing to be detached from the valve body.

Irrespective of whether a change between said first arrangement, and said second arrangement, is caused by relative movement between the valve assembly and the co-operating valve actuator, or not, the constructions of the valve assembly, and the co-operating valve actuator, may be such that, with the valve assembly and the co-operating valve actuator in said first arrangement, linear relative movement between the valve assembly, and the co-operating valve actuator, causes both the piston stem to be detached from the valve operator, and the actuator housing to be detached from the valve body; and said linear relative movement may be parallel to the longitudinal axis of the valve stem.

When the construction of the valve assembly is such, and the construction of the co-operating valve actuator is such, that both the valve operator is secured to the piston stem, and the valve body is secured to the actuator housing, by relative movement therebetween, and releasable means is provided to constrain the valve operator, the arrangement being such that, at least during such a securing action, the valve operator is releasably constrained to be movable only with the valve body in the securing action, and means to actuate, and to release, the constraint on the valve operator extends within the valve body, and through the actuator housing, in a direction parallel to said linear relative movement, between the valve assembly and the co-operating valve actuator, to cause the valve assembly to be detached from the valve actuator, the arrangement being such that, the means to actuate, and to release, the constraint on the valve operator is operable irrespective of whether the valve actuator is secured to the valve assembly, or not, and is undisturbed by detachment of the valve actuator from the valve assembly, or attachment of the valve actuator to the valve assembly. Such an arrangement for the means to actuate, and to release, the constraint on the valve operator, facilities its operation by remotely-controlled manipulative means, without it obstructing the use of the remotely-controlled manipulative means in other tasks to be performed on the combination of the valve assembly and co-operating valve actuator.

If, for example, the valve body is mounted fixedly within a sub-sea structure, such as a submerged well-head, the combination, of the valve assembly and the co-operating valve actuator, is arranged such that, with the co-operating valve actuator detached from the valve assembly, there is no ingress of a fluid at a high pressure into the valve actuator, or the valve assembly. Ports and passages in the valve body, and the actuator housing, may be closed automatically by provided poppet valves.

An advantageous form for the combination has the valve body with a re-entrant part, and the co-operating actuator, in its operable position, resides, at least partially, within the re-entrant part of the valve body.

Supply, and return, ports for fluid for the valve actuator may be provided within the valve body, and passages extending from these ports also are provided within the valve body, with the valve assembly secured to the co-operating valve actuator, the fluid passages within the valve body are in communication with co-operating fluid passages provided within the actuator housing, the co-operating fluid passages extending from the piston chamber within the actuator housing. Thus, a source of fluid for the valve actuator, conveniently, may be connected permanently to the valve body.

When the constructions of the valve assembly, and the co-operating valve actuator, are such that, with the valve assembly and the co-operating valve actuator in said first arrangement, linear relative movement between the valve assembly, and the co-operating valve actuator, causes both the piston stem to be detached from the valve operator, and the actuator housing to be detached from the valve body, at the interface between the valve body and the actuator housing, advantageously, the co-operating pairs of fluid passages, referred to in the preceding paragraph, extend in a direction parallel to said relative linear movement between the valve assembly and the co-operating valve actuator, and a seal is provided between each co-operating pair of fluid passages, the seals being compressed by the engagement of, and the securing of, the actuator housing with the valve body.

The combination may include two valve actuators, which are interchangable with each other, at least, in relation to being secured to the co-operating valve assembly; and possibly also includes one or two sources of fluid for the valve

actuators; at any time, one of the valve actuators is operably connected to the co-operating valve assembly, and one of the provided valve actuators comprises a replacement for the other valve actuator.

Supply, and return, ports for fluid for a first valve actuator may be provided within the co-operating valve body, and passages extending from these ports also are provided within the valve body, to communicate with co-operating fluid passages provided in a first, co-operating, actuator housing, the co-operating fluid passages extending from the piston chamber within the first actuator housing, supply, and return, ports for fluid for a second, replacement, valve actuator may be provided within the housing of the second valve actuator, and passages, extending from these ports to the associated piston chamber, also are provided within the second actuator housing. The arrangement may be such that a first source of fluid is connected permanently to the ports provided in the valve body, and a second source of fluid is connected to the ports provided in the housing of the second, replacement, valve actuator, before the second, replacement, valve actuator is attached to the valve assembly.

The combination may include remotely-controlled, transporting and manipulative means, the arrangement being such that the transporting and manipulative means causes the engagement of valve actuators with, and the detachment of the valve actuators from, the valve assembly; causes changes between said first arrangement and said second arrangeraent, of the valve assembly and co-operating valve actaators; and causes, if required, the connection of sources of fluid, and the release of the sources of fluid, within the combinstion.

The present invention will now be described by way of example with reference to the accompanying drawings, in which

Figure 1 is a split, sectional side view of part of a combination, in accordance with the present invention, of a valve assembly, comprising a valve and a valve operator, and a readily removable valve actuator, the section of a portion of the valve adjacent to the valve operator being on a line A-A shown in Figure 3, the section of the valve actuator, and an adjacent portion of the valve, and an adjacent portion of the valve operator, being on a line A-A' shown in Figure 3,

Figure 2 is a cross-section of the valve, on the line B-B of Figure 1 ,

Figure 3 is an end view of the combination, in the direction of the arrow X in Figure 1,

Figure 4 is a part section of the valve actuator, and an adjacent portion of the valve, on the line C-C of Figure 3,

Figure 5 corresponds to the pait of Figure 1 comprising a sectional side view of the valve actuator, an adjacent portion of the valve, and an adjacent portion of the valve operator, the section, however, being on a line D-D of Figure 6, and being of a modification, in accordance with the present invention, of the combination of Figure 1,

Figure 6 is an end view of the modified combination, in the direction of the arrow Y in Figure 5, and

Figure 7 shows, in accordance with the present invention, a structure comprising a sub-sea well-head, including several combinations each of a valve assembly, and a

co-operating, readily removable, valve actuator, and remotely-controlled, transporting and manipulative means for attaching, or removing, the valve actuators. Figure 1 shows part of a valve assembly comprising a valve 10 and a valve operator 11. The illustrated part of the valve has a valve body 12, there being shown of the valve body an end part 13, and a valve bonnet 14. Slidably mounted in the valve body 12 is a valve stem 15, a seal 16 being provided between the valve stem and the valve bonnet 14. Coaxial with the longitudinal axis 17 of the valve stem 15 is a generally cylindrical bore 18 in which the valve stem resides. The end part 13 of the valve body 12 has a cylindrically shaped

re-entrant portion 19, coaxial with the longitudinal axis 17 of the valve stem 15, and comprising an extension of the cylindrical bore 18 of the valve body. The valve operator 11 is also generally cylindrical in shape, and is of smaller diameter than the re-entrant portion 19 of the end part 13 of the valve body, but is coaxial therewith. The valve operator 11 is a close sliding fit within a portion 20 of the cylindrical bore 18 in the valve body adjacent to the larger diameter re-entrant portion 19. The valve stem 15 has an enlarged diameter end portion 21, of greater diameter than the valve operator 11, with which it is integral. At the extremity of the range of possible movement of the valve stem adjacent to the re-entrant portion 19 of the end part 13 of the valve body, the enlarged diameter end portion 21 of the valve stem 15 is a close fit within a portion 22 of the cylindrical bore 18.

As is shown in Figure 1, and also in Figure 2, Figure 2 comprising a section on the line B-B of Figure 1, means is provided to lock the valve stem 15 at the above-mentioned extremity of the range of its possible movement. The portion 22 of the cylindrical bore 18, in which the enlarged diameter end portion 21 of the valve stem is a close fit when at this extremity of its range of possible movement, is adjacent to a larger diameter portion 24 of the bore 18. Within the larger diameter portion 24 of the bore 18 resides a locking member 25, which locking member is arcuate in section and is radially slidably. displacable in relation to the longitudinal axis 17 of the valve stem. In its locking position, shown in dotted line form at 25' in Figure 2, the locking member 25 is at its radially inner location, and is in engagement with the enlarged diameter end portion 21 of the valve stem 15. In its release position, the locking member 25 is at its radially outer location, and the enlarged diameter end portion 21 of the valve stem is free to move within the larger diameter portion 24 of the bore 18. The locking member 25 is displaced between its release position, and its locking position by engagement with a rotating eccentric 26 mounted on a shaft 27 rotatably mounted in the end part 13 of the valve body 12. The eccentric 26 is provided within an insert 28 in the valve body. As shown in Figure 1 the longitudinal axis of the shaft 27 is parallel with the longitudinal axis 17 of the valve stem 15.

Figure 1 is a split, sectional side view of the valve assembly 10, 11, and of a co-operating valve actuator described in detail below. The lower portion of Figure 1 is of a portion of the valve 10 adjacent to the valve operator 11, and shows the locking means, 25, 26, and 27, the section of line B-B, comprising Figure 2 being through the locking means. As is more readily understood, by reference to Figure 3, comprising an end view of the combination of the valve assembly and the valve actuator, in the direction of the arrow X is Figure 1, the shaft 27 extends within the end part 13 of the valve body, and through the actuator housing, to be engagable by manipulative means at the end of the combination, to be rotated thereby, as also is described in detail below. The lower portion of Figure 1 is a section on the line A-A of Figure 3; and the upper portion of Figure 1, of the valve actuator, an adjacent portion of the valve 10, and an adjacent portion of the valve operator 11, is a section, on the line A-A' of Figure 3.

The locking means 25, 26 and 27, is also capable of locking the valve stem 15 at the other extremity of the range of its possible movement, in a similar manner. The enlarged diameter end portion 21 of the valve stem is a close fit, when at this extremity of its range of possible movement, in a portion 29 of the cylindrical bore 18 on the opposite side of the larger diameter portion 24 of the bore to the bore portion 22, the bore portion 29 being identical with the bore portion 22. In its locking position, the locking member 25 is in engagement with the enlarged diameter end portion 21 of the valve stem 15. In its release position, the enlarged diameter end portion 21 of the valve stem is free to move within the larger diameter portion 24 of the bore 18.

The locking member 25 is moved between its locking position, and its release position, when permitted by the eccentric 26, by fluid pressure within the larger diameter portion 24 of the bore 18.

The valve actuator 30 has a housing 31, with a cylindrical part 32 adapted to be a close fit in the cylindrically shaped re-rentrant part 19 of the end part 13 of the valve body 12. This cylindrical part 32 of the actuator housing 31 has provided therein a cylindrical chamber 33 for a piston 34. The piston stem 35 extends, along the longitudinal axis of the cylindrical chamber 33, through a seal 36 to be beyond the housing part 32. The piston stem 35 also extends along an extension of the longitudinal axis 17 of the valve stem 15. For convenience, hereinafter in this specification the term "extending longitudinally" is employed to describe any constituent part of the combination of the valve assembly 10, 11, and the valve actuator 30, extending co-axially with, at least in relation to an extension of, the longitudinal axis 17 of the valve stem 15, or extending parallel therewith. The end of the actuator housing 31, remote from the valve 10, comprises an integral circular plate 37, of the same diameter as the valve body 12. An apertured flange 38, to facilitate the pulling of the actuator from the re-entrant part 19 of the valve body, is provided on the plate 37.

The plate 37 is secured to the end part 13 of the valve body 12, in a readily releasable manner, by two bolts 39 engaging threaded apertures 40 in the valve body end part 13. The bolts 39 extend parallel to the longitudinal axis 17 of the valve stem 15; and extend beyond the end of the valve body 12, and terminate with a head 41, having a flange 42.

With an unillustrated first arrangement of the valve assembly 10, 11, and the co-operating valve actuator 30, the housing 31 of the readily removable valve actuator is engaged with, but is detachable from, the end part 13 of the valve body 12. Slots 43, shown in Figure 3, are provided in the plate 37 of the actuator housing 31, and the bolts 39 extend through enlarged parts 44 of these slots. The first arrangement is such that the valve actuator 30 is removed from the valve assembly 10, 11 by relative linear movement therebetween, in a direction parallel with the longitudinal axis 17 of the valve stem 15. The valve actuator 30 is removed by pulling the apertured flange 38, and the plate 37 of the actuator housing 31 is pulled passed the bolts 39 secured to the valve body 12.

In the illustrated second arrangement of the valve assembly 10, 11, and the co-operating valve actuator 30, the actuator housing 31 is secured to the end part 13 of the valve body 12. A change from the first arrangement, to the second arrangement, is by relative rotation between the valve assembly and the valve actuator. In this relative rotation the two bolts traverse along the associated slots 43 in the plate 37 of the actuator housing 31, from the enlarged parts 44, to smaller parts 45, shown in Figure 1. In the second arrangement the actuator housing 31 is secured to the valve body 12 by the plate 37 of the actuator housing being clamped between the valve body and the flanges 42 of the bolt heads. The clamping is caused by rotation of the actuator housing 31, in the clockwise direction as indicated by arrows Z in Figure 3. Rotation of the actuator housing 31 in the anti-clockwise direction causes a change from the second arrangement to the first arrangement.

The part 46 of the piston stem 35 extending beyond the housing part 32 of the actuator housing 31 has a generally conical shape, and is adapted to fit into a complementary conical shaped recess 47 in the valve operator 11. Flanges 48 are formed on the generally conical shaped part 46 of the piston stem 35. In the illustrated second arrangement of the valve assembly 10, 11, and the valve actuator 30, with the valve body 12 secured to the actuator housing 31, the flanges 48 on the part 46 of the piston stem 35 engage in complementary chanrfels 49 in the complementary, generally conical shaped recess 47 in the valve operator 11, securing the piston stem 35 to the valve operator 11. In the unillustrated first arrangement of the valve assembly 10, 11, and the valve actuator 30, the generally conical shaped part 46 of the piston stem 35 engages with, but is detachable from the complementary, generally conical shaped recess 47 in the valve operator. Rotation of the actuator housing 31 in the anti-clockwise direction as indicated by the arrows Z in Figure 3 causes the flanges 48 on the part 46 of the piston stem 35 to disengage from the complementary channels 49 in the recess 47 in the valve operator, enabling the pulling of the piston stem 35 from the valve operator 11, in a direction parallel to the longitudinal axis 17 of the valve stem 15.

In general, in the first arrangement of the valve assembly 10, 11, and the valve actuator 30, both the actuator housing 31 engages with, but is detachable from, the valve body 12, and the piston stem 35 engages with, but is detachable from, the valve operator 11. Detachment is by linear movement of the valve actuator 30 parallel with the longitudinal axis 17 of the valve stem 15. A change to the second arrangement of the valve assembly 10, 11, and the valve actuator 30, is by rotation of the valve actuator in the clockwise direction as indicated in Figure 3. In the second arrangement both the actuator housing 31 is secured to the valve body 12, and the piston stem 35 is secured to the valve operator 11.

At least during a change between the first and second arrangements, of either sense, it is required both that the valve operator 11 is constrained to rotate with the valve body 12, and the piston stem 35 is constrained to rotate with the actuator housing 31. Because the valve operator 11 is secured to the valve stem 15, the valve stem can be constrained to rotate with the valve body 12, instead of the valve operator. The valve stem 15 is so constrained by actuation of the locking means 25, 26 and 27, described above. The piston stem 35 is so constrained by engagement with the locked valve operator 11.

Thus, the construction of the combination of the valve assembly 10, 11, and the valve actuator 30, is adapted for the removal, and attachment, of the valve actuator, for example, by remotely-controlled manipulative means. With the valve actuator 30 secured to the valve assembly 10, 11, the valve actuator 30 can be rotated, by the manipulative means, in the anti-clockwise direction as indicated by the arrows Z in Figure 3, and there is a change from the second to the first arrangement. The valve actuator 30 then can be detached by the manipulative means pulling on the apertured flange 38 of the actuator housing 31. The manipulative means easily can attach the valve actuator 30 to the valve assembly 10, 11, in a

complementary manner.

As stated above, the shaft 27 of the locking means for the piston stem 15 extends in the valve body 12, and through the actuator housing 31. In particular, the shaft 27 extends through a slot 50 in the plate 37 of the actuator housing 31, and is engagable by the manipulative means beyond the end of the combination of the valve assembly 10, 11, and the valve actuator 30. Thus, the manipulative means can rotate the shaft 27, and, hence, the eccentric 26 to cause displacement of the locking member 25 from its release position to its locking position; and to allow displacement of the locking member in the reverse direction; when required. The slot 50, through which the shaft 27 extends is arcuate in shape, and the arrangement is such that it is irrelevant whether the valve assembly 10, 11, and the valve actuator 30, are in their first or second arrangements. Because, the shaft 27 extends parallel to the direction of linear relative movement between the valve assembly 10, 11, and the valve actuator 30, the shaft is undisturbed by detachment, or attachment, of the valve actuator. Further, the shaft 27 does not obstruct the use of the manipulative means in other tasks to be performed on the combination of the valve assembly and co-operating valve actuator.

Inevitably when the valve actuator 30 is detached from the valve assembly 10, 11, the valve stem 15 is locked at the extremity of the range of its possible movement adjacent to the valve actuator, as described above. Thus, if the combination of the valve assembly 10, 11, and the valve actuator 30. is located in an environment of a fluid at high pressure, such as being submerged at depth beneath the sea, it is possible for this fluid to enter the valve only by traversing the close fitting between the valve operator 11 and the co-operating portion 20 of the bore 18 in the valve body; and between the close fitting between the enlarged diameter end portion 21 of the valve stem 15 and the portion 22. of the bore 18. The seal 36 prevents ingress of the high pressure fluid into valve actuator 30. With the valve actuator 30 secured to the valve assembly 10, 11, because the valve actuator partially resides in the re-entrant portion 19 of the end part 13 of the valve body 12, and is arranged to be a close fit therein, ingress of high pressure fluid into the valve assembly is made additionally more difficult.

In order tc reduce the number of tasks required to be performed by the manipulative means when attaching, or detaching, the valve actuator 30, ports 51 and 52, for connection to a source of fluid, not shown, for the valve actuator, are provided in the valve body 12. The port 52 is shown in the part section of Figure 4, on the line C-C of Figure 3, whilst port 51 is shown in Figure 1. Passages 53 and 54, extend within the valve body 12, to extend, respectively, from the ports 51 and 52. Co-operating passages 55 and 56, extend within the actuator housing 31, from the piston chamber 33, to communicate, respectively, with the passages 53 and 54, in the valve body 12. The passage 56 is formed in the plate 37 of the actuator housing 31. For convenience in providing the passage 55 in the actuator housing 31, the cylindrical part 32 of the housing has a composite construction, comprising an outer sleeve part 57 secured to an inner part 58 integral with the plate

37. A portion of the passage 55 is provided through the inner part 58, and another portion is provided at the interface between the outer sleeve part 57 and the inner part 58. The sleeve 57 is provided with a lug 59, and the remaining portion of the passage 55 is formed through the lug 59, and at an interface between the lug and a co-operating portion of the valve body 12. When the valve actuator 30 rotates relative to the valve assembly 10, 11, between the second and first arrangements thereof, the lug 59 traverses an actuate shaped channel, not shown, formed in the valve body 12, to be beneath a longitudinally extending slot, not shown, formed in the valve body. Hence, when the valve actuator 30 is detached from the valve assembly 10, 11, the lug 59 traverses through the associated longitudinally extending slot, without hindrance.

The combination of the valve assembly 10, 11, and valve actuator 30, may be part of a structure submerged at a depth such that it is subjected to a high pressure. Consequently, it is required to provide a good seal between each pair of co-operating passages 53 and 55, and 54 and 56, at the interface between the valve body 12 and co-operating parts, respectively, the lug 59 and the plate 37, of the actuator housing 31. An annular shaped seal 60 is provided for each pair of co-operating passages 53 and 55, and 54 and 56; and portions of the passages adjacent to the seals 60 extend parallel with the longitudinal axis 17 of the valve stem 15, and, hence, extend parallel to the linear movement of the valve actuator when being attached, or detached. Thus, the seals 60, advantageously, are compressed by the engagement of, and the securing of, the actuator housing 31 with the valve body 12. The seals 60 are indicated in dotted form in Figure 3.

Upon the detachment of the valve actuator 30 from the fluid assembly 10, 11; and/or upon the detachment of the source of fluid from the ports 51 and 52; poppet valves provided within the combination automatically prevent any unintentional ingress of fluid into the ports and co-operating passages 53 to 56.

Figures 5 and 6 show a modification of the combination of the valve assembly 10, 11, and the valve actuator 30, providing an alternative manner of securing the actuator housing to the valve body to that shown in Figures 1 and 3. Parts of the embodiment of Figures 5 and 6 identical with, or closely resembling, parts of the embodiment of Figures 1 and 3 are identified by the same reference numerals in Figures 5 and 6. Figure 5, for convenience, corresponds only to the upper part of Figure 1. Figure 6 corresponds to Figure 3, but is an end view in the direction of the arrow Y of Figure 5. Figure 5 comprises a section on the line D-D of Figure 6.

The plate 37' of the actuator housing 31' of the embodiment of Figures 5 and 6 extends only within the

cylindrical sleeve 57 of the housing. Two lugs 59' are provided on the inner part 58 of the composite cylindrical part 32' of the housing 31', only one being shown in Figure 5, but both correspond to the lug 59 of Figure 1. Both lugs 59' are indicated in dotted form in Figure 6. The lugs 59' extend within arcuate slots 62 in the valve body 12. When the valve actuator 30 rotates relative to the valve assembly 10, 11, between the second and first arrangements thereof, the lugs 59' traverse the arcuate slots 59' to be beneath longitudinally extending slots 63 also formed in the valve body 12. Hence, when the valve actuator 30 is detached from the valve assembly 10, 11, the lugs 59' traverse through the associated longitudinally extending slots 63, without hindrance. With the valve actuator 30, and the valve assembly 10, 11, in the second arrangement, the valve body 12 is secured to the actuator housing 31', the lugs 59' are at the extremities of the arcuate slots 62 remote from the longitudinally extending slots 63, and are clamped to the valve body by engagement with longitudinally extending bolts 39', extending through the portions of the valve body 12 substantially coplanar with the actuator plate 37', and partially defining the slots 62 and 63.

The combination of the valve assembly, and the co-operating valve actuator, may be such that a change between the first and second arrangements thereof is caused other than solely by relative rotation therebetween, and possibly is caused other than solely by any form of relative movement therebetween. For example, a change between the first and second arrangements may be caused without any relative rotation between the valve assembly and the co-operating valve actuator, and possibly is caused without any relative movement

therebetween.

The constructions of the valve assembly and the co-operating valve actuator may be such that the valve body is secured to the actuator housing independently of the securing of the piston stem to the valve operator.

With any such alternative constructions of the valve assembly and the co-operating valve actuator it may not be necessary to constrain the valve operator for movement only with the valve body, and/or to constrain the piston stem for movement only with the actuator housing, during the securing of the valve assembly to the co-operating valve actuator.

If means to constrain the valve operator for movement only with the valve body, and/or to constrain the piston stem for movement only with the actuator housing, is required, it may have any convenient form.

Detachment, and attachment, of the valve actuator and the co-operating valve assembly may be other than by linear relative movement therebetween parallel to the longitudinal axis of the valve stem, and may be by any form of relative movement therebetween.

It is not essential that detachment, and attachment, of the valve actuator and the co-operating valve assembly is by relative movement therebetween of the same form as relative movement therebetween causing a change between said first and second arrangements thereof.

It is known, for example, in the sub-sea production of hydrocarbons, to use remotely-controlled submersible vehicles to perform tasks, such as the replacement of valve actuators on sea bed structures, such as well-heads. It is known for such a vehicle to operate in conjunction with a cage-like garage to which it is tethered, the cage providing transport for the vehicle between a surface vessel and the work site. The cage-like garage is connected by an electro-hydraulic umbilical to the surface vessel.

Figure 7 shows a sub-sea structure comprising a well-head Christmas tree, indicated generally at 70, and including combinations of valve assemblies and valve actuators, such as described above, with the valve assemblies fixedly mounted within the structure 70. The combinations are operated by electrical and/or hydraulic power and control signals, from a remote site, by an electro-hydraulic umbilical 71. The umbilical 71 contains a plurality of electrical and/or hydraulic channels, for the transmission of the power and control signals from the remote site to the sub-sea structure.

The structure sits on a prepared bed.

A vertical docking leg 72 is also provided, secured in any convenient manner to the sea-bed at a location adjacent to, but spaced from the structure 70. For convenience, two production flow lines 73, to extend from the structure 70 to remote means to receive the produced hydrocarbons, are secured to the base of the vertical docking leg 72, serving to anchor the ends of the flow lines 73. Connections 73' are provided between the ends of the flow lines 73 and the structure 70.

The main purpose of the vertical docking leg 72 is to provide means to support the cage-like garage 74 for a remotely-controlled vehicle 75. The umbilical from a surface vessel to the garage is indicated at 76.

In operation, the remotely-controlled vehicle 75 is capable of leaving, and returning to, the garage 74, being controlled via an electro-hydraulic umbilical 77 connecting the vehicle to means fixed to the garage. The vehicle 75 moves over the sea bed, and/or is capable of docking on the structure 70. In addition to propulsion, lighting, and viewing, means,

(not shown), the vehicle 75 has manipulative means 78, and is supported by a tray 79, carrying tools and replacement parts

(not shown). As indicated above, the combination of the valve assembly 10, 11 and valve actuator 30, of Figures 1 to 4, or the modification thereof shown in Figures 5 and 6, is adapted so that removal, and attachment, of the valve actuator by

remotely-controlled manipulative means is facilitated. The manner of detachment, and attachment, of the valve actuator 30 to the valve assembly 10, 11, by remotely-controlled manipulative meams is described above.

The remotely-controlled vehicle 75 may carry a replacement actuator, interchangable with valve actuators within the structure 70. The constructions of the valve assembly 10, 11, and the valve actuator 30, described above are advantageous in relation to the arrangement of the ports, and the co-operating passages, for fluid for the valve actuator, because the source of fluid may be connected permanently to the valve body, even though the valve actuator is to be replaced, and so not requiring any action of the manipulative means in this respect.

When at least two valve actuators are interchangable with each other, at least, in relation to being secured to the co-operating valve assembly, at any time, at most one of the valve actuators is operably connected to the co-operating valve assembly, whilst each other valve actuator comprises a replacement therefor, and is carried by the remotely-controlled, transporting and manipulative means.

In addition, when supply, and return, ports for fluid for a first valve actuator are provided within the co-operating valve body, (and passages extending from these ports also are provided within the valve body, to communicate with co-operating fluid passages provided in the first, co-operating, actuator housing, the co-operating fluid passages to extend from the piston chamber within the first actuator housing), and supply, and return, ports for fluid for a second, replacement, valve actuator are provided within the housing of the second valve actuator, (and passages, extending from the ports to the

associated piston chamber, also are provided within the second actuator housing), a first source of fluid is connected to the ports provided in the valve body, a second source of fluid is connected to the ports provided in the housing of the second, replacement, valve actuator, and the second valve actuator, and the associated second source of fluid, comprise an operable part of the remotely-controlled, transporting and manipulative means.

A replacement actuator, and the actuator it replaces, unlike the actuator 30 described above, each may have ports to be connected to a source of fluid formed within the actuator housing. Thus, in addition to the attachment, and detachment, of valve actuators to the valve assembly fixedly mounted within the structure 70, other tasks, which are required to be performed by the remotely-controlled manipulative means, includes the connection, and release, of sources of fluid for the valve actuators.

It is possible that a replacement actuator has ports for fluid provided within its housing, and the valve body has ports for fluid formed therein, for co-operation with a valve actuator which does not have ports for fluid provided within its housing. A single source of fluid may be provided for both the valve actuator to be replaced, and the replacement valve

actuator, the source being transferred by the manipulative means to be connected to the ports within the housing of the replacement valve actuator, when this actuator is secured to the valve assembly. However, advantageously, such a replacement valve actuator, and an associated source of fluid, together, comprise an operable part of the manipulative means, and are connected together before the manipulative means causes the securing of the replacement valve actuator to be secured to the valve assembly. The other source of fluid, for the valve actuator to be replaced, remains connected to the valve body during the time the replacement valve operator, and its associated fluid source, are secured to the valve assembly. Hence, no action of the manipulative means is required in relation to the connection, or release, of fluid sources.

Claims

Claims:

1. A valve assembly has

a valve operator, and

a valve including a valve stem slidably mounted, for movement along its longitudinal axis, in a valve body, with the valve stem arranged to move with the valve operator, the assembly being arranged to co-operate with a valve actuator, the valve actuator to comprise a fluid actuable piston slidably mounted, for movement along the longitudinal axis of its stem, in a chamber provided in an actuator housing, with the piston stem to extend from the actuator housing, and to be coaxial with the piston stem,

the construction of the valve assembly being such, and the construction of the co-operating valve actuator to be such, that there is capable of being a first arrangement of the valve assembly and the co-operating valve actuator in which both the valve operator is engaged with, but is detachable from, the piston stem, and the valve body is engaged with, but is detachable from, the actuator housing, and

there is capable of being a second arrangement o f the valve assembly and the co-operating valve actuator in which both the valve operator is secured to the piston stem, and the valve body is secured to the actuator housing.

2. An assembly as claimed in claim 1, in which the

construction of the valve assembly is such, and the construction of the co-operating valve actuator is to be such, that both the valve operator is to be secured to the piston stem, and the valve body is to be secured to the actuator housing, solely by relative movement between the valve assembly and the valve actuator, and the arrangement is such that, at least during such a securing action, the valve operator is constrained to be movable only with the valve body.

3. An assembly as claimed in claim 2, in which the construction of the valve assembly is such, and the construction of the co-operating valve actuator is to be such, that both the valve operator is to be secured to the piston stem, and the valve body is to be secured to the actuator housing, by relative movement between the valve assembly and the valve actuator, and in which assembly there is provided releasable means to constrain the valve operator, the arrangement being such that, at least during such a securing action, the valve operator is releasably constrained to be movable only with the valve body.

4. An assembly as claimed in claim 3, in which the construction of the valve assembly is such, and the construction of the co-operating valve actuator is to be such, that both the valve operator is to be secured to the piston s tem, and the valve body is to be secured to the actuator housing, by relative rotation between the valve assembly and the valve actuator, and in which assembly there is provided releasable means to constrain the valve operator, the arrangement being such that, at least during such a securing action, the valve operator is releasably constrained to be rotatable only with the valve body.

5. An assembly as claimed in claim 2, or claim 3, or claim 4, having means to lock, in a releasable manner, the valve operator at a predetermined position within the valve body.

6. An assembly as claimed in claim 5, in which the locking means includes a member slidably displacable within the valve body, in a radial direction in relation to the longitudinal axis of the valve stem, and between a release position and a locking position.

7. An assembly as claimed in claim 6, in which an

eccentric is rotatably mounted within the valve body, rotation of the eccentric being arranged to cause displacement of the locking member from the release position to the locking position.

8. An assembly as claimed in claim 6, or claim 7, in which the valve operator is secured to the valve stem, and the locking member, when in its locking position, is arranged to engage with an enlarged diameter part of the valve stem, with the valve stem at an extremity of its possible range of movement within the valve body.

9. A combination including a valve assembly as claimed in any one of the preceding claims, and a co-operating valve actuator comprising a fluid actuable piston slidably mourrted, for movement along the longitudinal axis of its stem, in a chamber provided in an actuator housing, with the piston stem extending from the actuator housing, and being coaxial with the piston stem, the constructions of the valve assembly and the co-operating valve actuator being such that, at least, there is capable of being a first arrangement of the valve assembly and the co-operating valve actuator in which both the valve operator is engaged with, but is detachable from, the piston stem, and the valve body is engaged with, but is detachable from, the actuator housing, and, at least, there is capable of being a second arrangement of the valve assembly and the co-operating valve actuator in which both the valve operator is secured to the piston stem, and the valve body is secured to the actuator housing.

10. A combination as claimed in claim 9, in which the constructions of the valve assembly, and the co-operating valve actuator, are such that the valve body is secured to the actuator housing by relative movement therebetween.

11. A combination as claimed in claim 10, in which the constructions of the valve assembly, and the co-operating valve actuator, are such that the valve body is secured to the actuator housing by relative rotation therebetween.

12. A combination as claimed in any one of claims 9 to 11, in which the constructions of the valve assembly, and the co-operating valve actuator, are such that the valve operator is secured to the piston stem by relative movement therebetween.

13. A combination as claimed in claim 12, in which the constructions of the valve assembly, and the co-operating valve actuator, are such that the valve operator is secured to the piston stem by relative rotation therebetween.

14. A combination as claimed in any one of claims 9 to 13, in which the constructions of the valve assembly, and the co-operating valve actuator, are such that both the valve operator is secured to the piston stem, and the valve body is secured to the actuator housing, by relative movement between the valve assembly and the valve actuator, and the arrangement is such that, at least during such a securing action, the piston stem is constrained to be movable only with the actuator housing in the securing action.

15. A combination as claimed in claim 14, in which the piston stem is arranged to be constrained in the required manner, during the securing action, by engagement with the valve operator, with the valve operator constrained to be movable only with the valve body in the securing action.

16. A combination as claimed in any one of claims 9 to 15, in which the construction of the valve assembly is such, and the construction of the co-operating valve actuator is such, that a change between said first arrangement and said second arrangement, of the valve assembly and the co-operating valve actuator, is caused by relative movement, between the valve assembly and the co-operating valve actuator, different in form from the relative movement therebetween, causing, with the valve assembly and the co-operating valve actuator in said first arrangement, both the piston stem to be detached from the valve operator, and the actuator housing to be detached from the valve body.

17. A combination as claimed in any one of claims 9 to 16, in which the construction of the valve assembly is such, and the construction of the co-operating valve actuator is such, that, with the valve assembly and the co-operating valve actuator in said first arrangement linear relative movement between the valve assembly, and the co-operating valve actuator, causes both the piston stem to be detached from the valve operator, and the actuator housing to be detached from the valve body.

18. A combination as claimed in claim 17, in which said linear relative movement is parallel to the longitudinal axis of the valve stem.

19. A combination as claimed in claim 18, in which the construction of the valve assembly is such, and the construction of the co-operating valve actuator is such, that both the valve operator is secured to the piston stem, and the valve body is secured to the actuator housing, by relative movement therebetween, and releasable means is provided to constrain the valve operator, the arrangement being such that, at least during such a securing action, the valve operator is releasably constrained to be movable only with the valve body in the securing action, and means to actuate, and to release, the constraint on the valve operator is provided, and the means to actuate, and to release, the constraint on the valve operator extends within the valve body, and through the actuat-or housing, in a direction parallel to said linear relative movement, between the valve assembly and the co-operating valve actuator, to cause the valve assembly to be detached from the valve actuator, the arrangement being such that the means to actuate, and to release, the constraint on the valve operator is operable irrespective of whether the valve actuator is secured to the valve assembly, or not, and is undisturbed by detachment of the valve actuator from the valve assembly, or attachment of the valve actuator to the valve assembly.

20. A combination as claimed in any one of claims 9 to 19, including a structure with the valve body mounted fixedly within the structure.

21. A combination as claimed in claim 20, in which the structure comprises a well-head to be connected to a hydrocarbon-extracting production line.

22. A combination as claimed in any one of claims 9 to 21, in which the valve assembly, and the co-operating valve actuator, is arranged such that, with the co-operating valve actuator detached from the valve assembly, there is no ingress of a fluid at a high pressure into the valve actuator, or the valve assembly.

23. A combination as claimed in any one of claims 9 to 22, in which the valve body has a re-entrant part, and the

co-operating actuator, in its operable position, resides, at least partially, within the re-entrant part of the valve body.

24. A combination as claimed in any one of claims 9 to 23, in which supply, and return, ports for fluid for the valve actuator are provided within the valve body, and passages extending from these ports also are provided within the valve body, and with the valve assembly secured to the co-operating valve actuator, the fluid passages within the valve body are in communication with co-operating fluid passages provided within the actuator housing, the co-operating fluid passages extending from the piston chamber within the actuator housing.

25. A combination as claimed in claim 24, in which the construction of the valve assembly is such, and the construction of the co-operating valve actuator is such, that, with the valve assembly and the co-operating valve actuator in said first arrangement, linear relative movement between the valve assembly, and the co-operating valve actuator, causes both the piston stem to be detached from the valve operator, and the actuator housing to be detached from the valve body, at the interface between the valve body and the actuator housing, the co-operating pairs of fluid passages extend in a direction parallel to said relative linear movement between the valve assembly and the co-operating valve actuator, and a seal is provided between each co-operating pair of fluid passages.

26. A combination as claimed in any one of claims 9 to 25, having two valve actuators which are interchangable with each other, at least, in relation to being secured to the

co-operating valve assembly, wherein at any time, one of the valve actuators is operably connected to the co-operating valve assembly and one of the provided valve actuators comprises a replacement for the other valve actuator.

27. A combination as claimed in claim 26, in which supply, and return, ports for fluid for a first valve actuator are provided within the co-operating valve body, and passages extending from these ports also are provided within the valve body, to communicate with co-operating fluid passages provided in the first, co-operating, actuator housing, the co-operating fluid passages extending from the piston chamber within the first actuator housing, supply, and return, ports for fluid for a second, replacement, valve, actuator are provided within the housing of the second valve actuator, and passages, extending from these ports to the associated piston chamber, also are provided within the second actuator housing.

28. A combination as claimed in claim 27, in which a first source of fluid is connected to the ports provided in the valve body, and a second source of fluid is connected to the ports provided in the housing of the second, replacement, valve actuator.

29. A combination as claimed in any one of claims 9 to 28, including remotely-controlled, transporting and manipulative means, the arrangement being such that the transporting and manipulative means causes the engagement of valve actuators with, and the detachment of the valve actuators from, the valve assembly; causes changes between said first arrangement and said second arrangement, of the valve assembly and co-operating valve actuators; and causes, if required, the connection of sources of fluid, and the release of the sources of fluid, within the combination.

30. A combination as claimed in claim 29, having two valve actuators which are interchangable with each other, at least, in relation to being secured to the co-operating valve assembly, at any time, one of the valve actuators is operably connected to the co-operating valve assembly, and one of the provided valve actuators comprises a replacement for the other valve actuator, and is carried by the transporting and manipulative means.

31. A combination as claimed in claim 30, having supply, and return, ports for fluid for a first valve actuator provided within the co-operating valve body, and passages extending from these ports also are provided within the valve body, to

communicate with co-operating fluid passages provided in the first, co-operating, actuator housing, the co-operating fluid passages extending from the piston chamber within the first actuator housing, supply, and return, ports for fluid for a second, replacement, valve actuator are provided within the housing of the second valve actuator, and passages, extending from these ports to the associated piston chamber, also are provided within the second actuator housing, a first source of fluid is connected to the ports provided in the valve body, a second source of fluid is connected to the ports provided in the housing of the second, replacement, valve actuator, and the second valve actuator, and the associated second source of fluid, comprises an operable part of the transporting and manipulative means.

32. A valve assembly, or the modification thereof, substantially as described herein, with reference to Figures 1 to 6 of the accompanying drawings.

33. A combination of a valve assembly, and at least one readily removable valve actuator, substantially as described herein, with reference to Figures 1 to 4 of the accompanying drawings.

34. A combination of a valve assembly, and at least one readily removable valve actuator, substantially as described herein, with reference to Figures 1, 2, 5 and 6 of the accompanying drawings.

35. A combination of a valve assembly, at least one readily removable valve actuator, and a co-operating structure, substantially as described herein, with reference to the accompanying drawings.

36. A combination of a valve assembly, at least one readily removable valve actuator, and remotely-controlled, transporting and manipulative means, substantially as described herein, with reference to the accompanying drawings.