Valve component

Abstract

A valve component for a valve, the valve comprises a valve housing defining a hollow bore along which flowable material may flow. The valve component comprises a valve member movable between a valve open position for the valve member to open the hollow bore and a valve closed position for the valve member to close the hollow bore, and a valve control mechanism including a drive member configured to be operable to move the valve member between the valve open position and the valve closed position, the drive member operable to rotate the valve member between the valve open position and a valve intermediate position and to linearly move the valve member between the valve intermediate position and the valve closed position.

Claims

1. A valve component for a valve, the valve comprising a valve housing defining a hollow bore along which flowable material may flow, the valve component comprising: a valve member movable between: a valve open position for the valve member to open the hollow bore; and a valve closed position for the valve member to close the hollow bore; a valve control mechanism including a drive member configured to be operable to move the valve member between the valve open position and the valve closed position, the drive member operable to rotate the valve member between the valve open position and a valve intermediate position and to linearly move the valve member between the valve intermediate position and the valve closed position, wherein the valve control mechanism includes a cam to drive the drive member; and a retention device including an engagement member arranged to engage the cam in the valve open position of the valve member so that the engagement member locates the cam to resist or prevent rotation of the valve member away from the valve open position towards the valve intermediate position.

2. A valve component according to claim 1 wherein the valve control mechanism includes a guide element for guiding the drive member during its operation to rotate the valve member between the valve open position and the valve intermediate position and to linearly move the valve member between the valve intermediate position and the valve closed position.

3. A valve component according to claim 2 wherein the guide element includes a guide slot.

4. A valve component according to claim 3 wherein the guide slot includes first and second guide slot portions, the first guide slot portion shaped to define an arcuate guide slot portion, the second guide slot portion shaped to define a linear guide slot portion.

5. A valve component according to claim 1 wherein the cam includes a cam slot to engage the drive member.

6. A valve component according to claim 5 wherein the cam slot includes a recess arranged to receive the drive member in the valve closed position of the valve member so that the recess locates the drive member to resist or prevent linear movement of the valve member away from the valve closed position towards the valve intermediate position.

7. A valve component according to claim 5 where the cam slot is shaped to define an arcuate cam slot or a crescent-shaped cam slot.

8. A valve component according to claim 1 wherein the cam includes a cam slot to engage the drive member, and wherein the cam slot includes a recess arranged to receive the drive member in the valve open position of the valve member.

9. A valve component according to claim 1 wherein the retention device includes a biasing member configured to apply a biasing force to the engagement member so that the engagement member is urged to engage the cam in the valve open position of the valve member.

10. A valve component according to claim 1 wherein the valve member includes a closure portion for closing the hollow bore, the valve member further including a biasing member configured to apply a biasing force to the closure portion so that the closure portion is urged to close the hollow bore in the valve closed position of the valve member.

11. A valve component according to claim 10 wherein the valve member includes first and second valve member portions, the first valve member portion operably mounted onto a base of the valve component, the second valve member portion configured as the closure portion, the second valve member portion operably mounted on the first valve member portion to permit movement of the second valve member portion relative to the first valve member portion.

12. A valve component according to claim 11 wherein the biasing member is arranged between the first and second valve member portions.

13. A valve component according to claim 12 wherein the biasing member is housed inside an internal cavity formed between the first and second valve member portions.

14. A valve component according to claim 10 wherein the biasing member is compressible.

15. A valve component according to claim 10 wherein the biasing member is a disc spring.

16. A valve component according to claim 1 wherein the drive member is configured to be operable to vary the speed at which the valve member is rotated between the valve open position and the valve intermediate position and/or to vary the speed at which the valve member is linearly moved between the valve intermediate position and the valve closed position.

17. A valve, for use in a fluid conduit, comprising: a valve housing defining a hollow bore along which flowable material may flow; and a valve component according to claim 1, wherein the valve component is located inside the valve housing.

18. A fluid conduit comprising a valve according to claim 17.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Preferred embodiments of the invention will now be described, by way of non-limiting examples, with reference to the accompanying drawings in which:

(2) FIGS. 1a to 1c show a valve according to a first embodiment of the invention;

(3) FIG. 2 shows a valve component forming part of the valve of FIGS. 1a to 1c;

(4) FIG. 3 shows a side view of the valve component of FIG. 2;

(5) FIG. 4 shows a cross-sectional view along section A-A′ of the valve component of FIG. 3;

(6) FIG. 5 shows a section view of a valve member forming part of the valve component of FIG. 2;

(7) FIG. 6 shows an exploded view of the valve component of FIG. 2;

(8) FIG. 7 illustrates the operation of the valve component of FIG. 2;

(9) FIGS. 8a to 8f show a valve according to a second embodiment of the invention;

(10) FIG. 9 shows a valve component forming part of the valve of FIGS. 8a to 8f;

(11) FIGS. 10a to 10c shows side views of the valve component of FIG. 9;

(12) FIGS. 11a and 11b show cross-sectional views along section A-A′ of the valve component of FIGS. 10a and 10c respectively;

(13) FIG. 12 shows a section view of a valve member forming part of the valve component of FIG. 9;

(14) FIG. 13 shows an exploded view of the valve component of FIG. 9; and

(15) FIGS. 14a to 14c illustrate the operation of the valve component of FIG. 9.

(16) The figures are not necessarily to scale, and certain features and certain views of the figures may be shown exaggerated in scale or in schematic form in the interests of clarity and conciseness.

DETAILED DESCRIPTION

(17) Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.

(18) A valve according to a first embodiment of the invention is shown in FIGS. 1a to 1c and is designated generally by the reference numeral 10.

(19) The valve 10 is a bidirectional valve. The valve 10 includes a valve housing 12 and a valve component 14.

(20) The valve housing 12 defines a hollow bore 16 along which flowable material may flow in both directions. The valve component 14 is received inside the hollow bore 16 of the valve housing 12. The valve housing 12 further includes a compressible seal 18 that extends around the circumference of a longitudinal section of the hollow bore 16. The seal may be a tapered seal or a flat seal.

(21) In use, the valve housing 12 is connected to a pipeline (not shown) so that the hollow bore 16 of the valve housing 12 is continuous with a hollow bore of the pipeline.

(22) The structure of the valve component 14 is shown in FIGS. 2 to 6.

(23) The valve component 14 includes a valve member and a valve control mechanism.

(24) The valve member includes a flap portion 20 that is shaped in the form of a disc. The diameter of the flap portion 20 is sized so that the flap portion 20 is capable of sealingly engaging with the seal 18 to close the hollow bore 16 of the valve housing 12. Preferably the diameter of the flap portion 20 is 4, 6, 8, 10 or 12 inches.

(25) The valve member further includes a stem portion 22 that projects perpendicularly from a circular surface of the flap portion 20. The stem portion 22 includes proximal and distal ends 22a,22b. The proximal end 22a defines the point of attachment between the stem portion 22 and the flap portion 20. The distal end 22b defines the furthest point of the stem portion 22 away from the flap portion 20. The stem portion 22 includes an internally threaded aperture 24 located near the distal end 22b of the stem portion 22. The stem portion 22 further includes a valve member slot 26 that extends along the stem portion 22 between the aperture and the proximal end 22a of the stem portion 22. The valve member slot 26 is shaped to define a linear slot.

(26) The valve control mechanism includes a pair of drive members 28, a guide element 30, a projecting member 32 and a pair of cams 34. The projecting member 32 is in the form of a shaft but may be an axle or rod in other embodiments.

(27) Each drive member 28 is in the form of a shoulder bolt that is screwed into the internal thread of the threaded aperture 24 of the stem portion 22.

(28) The guide element 30 is in the form of a mounting bracket 30 that includes a pair of opposing walls 36, each of which includes a guide slot 38. The mounting bracket 30 further includes a base 40 that interconnects the pair of opposing walls 36 and is secured to a wall of the valve housing 12.

(29) The valve member, drive members 28 and guide element 30 are arranged so that the stem portion 22 of the valve member is located between the pair of opposing walls 36, and each drive member 28 extends through the guide slot 38 of the respective opposing wall 36.

(30) The guide slot 38 in each opposing wall 36 includes first and second guide slot portions 42,44. The first guide slot portion 42 is shaped to define a one-quarter arcuate guide slot portion. The second guide slot portion 44 is shaped to define a linear guide slot portion. Each guide slot portion 42,44 includes first and second ends. For each guide slot 38, the first end of the first guide slot portion 42 defines a first terminating end 46 of the guide slot 38, the second end of the guide slot portion defines a second terminating end 48 of the guide slot 38, and the second end of the first guide slot portion 42 is continuously connected to the first end of the second guide slot portion 44 to define a point of connection 50 between the second end of the first guide slot portion 42 and the first end of the second guide slot portion 44.

(31) Each opposing wall 36 further includes a pivot aperture 52. The shaft 32 not only extends through the pivot apertures 52 and through pivot bushes 54 respectively mounted in the pivot apertures 52, but also extends through a tubular pivot sleeve 56 that is located between the two pivot apertures 52. The pivot sleeve 56 extends through the valve member slot 26 in the stem portion 22 of the valve member. The pivot sleeve 56 is sized and shaped so that the valve member is rotatable about the pivot sleeve 56 and so that the pivot sleeve 56 is linearly movable along the length of the valve member slot 26.

(32) The relative positions of the first guide slot portion 42 and pivot aperture 52 in each opposing wall 36 are arranged so that the movement of the drive member 28 along the first guide slot portion 42 causes rotation of the valve member about the pivot sleeve 56. In this manner the valve member is pivotally mounted onto the mounting bracket 30.

(33) The relative positions of the second guide slot portion 44 and pivot aperture 52 in each opposing wall 36 are arranged so that the movement of the drive member 28 along the second guide slot portion 44 causes linear movement of the valve member relative to the pivot sleeve 56 and towards the seal 18.

(34) Each cam 34 is in the form of a cam plate and is mounted onto the shaft 32 so that each cam 34 flanks an outer wall of a respective one of the opposing walls 36 of the mounting bracket 30. The mounting of each cam 34 onto the shaft 32 allows each cam 34 to be rotated when the shaft 32 is rotated in use.

(35) Each cam 34 includes a cam slot 58 through which the respective drive member 28 extends. Each drive member 28 further extends through a cam bush 60 mounted in the corresponding cam slot 58 and a cam bush 60 mounted in the corresponding guide slot 38. The cam slot 58 of each cam 34 is shaped so that the rotation of the corresponding cam 34 drives the corresponding drive member 28 to move back and forth along the corresponding guide slot 38 between its terminating ends 46,48. The interaction of the cams 34 and drive members 28 in this manner permits a rotary motion applied to the shaft 32 to be converted by the cams 34 into a combination of rotary and linear motion that is required to drive each drive member 28 along the corresponding guide slot 38.

(36) The shaft 32 further extends through a wall of the valve housing 12 so that it can be externally rotated from the exterior of the valve housing 12. The shaft 32 may be rotated by hand or machine.

(37) Operation of the valve 10 is described as follows, with reference to FIG. 7.

(38) When the drive member 28 is located at the first end of the first guide slot portion 42 (i.e. the first terminating end 46 of the guide slot 38), the valve member is in a valve open position 62 in which the flap portion 20 is perpendicular to the cross-section of the hollow bore 16 of the valve housing 12 (i.e. the flap portion 20 bisects the hollow bore 16 of the valve housing 12). This opens the hollow bore 16 of the valve housing 12 and thereby permits the flowable material to flow along the hollow bore 16 of the valve housing 12 and therefore the hollow bore of the connected pipeline. The configuration of the valve member as a flap portion 20 that bisects the hollow bore 16 of the valve housing 12 in the valve open position 62 minimizes the resistance to the flow of the flowable material through the hollow bore 16 of the valve housing 12.

(39) The provision of the guide and cam slots 38,58 in the valve component 14 allows the valve member to be securely held in the valve open position 62 during the flow of flowable material through the hollow bore 16 in both flow directions. More specifically, the interaction of the drive member 28 with the guide and cam slots 38,58 enables the cam 34 to be held stationary, by holding the shaft 32 stationary, in order to securely hold the valve member in the valve open position whilst flowable material flowing in the hollow bore 16 continuously pushes against the valve member. Omission of either the guide or cam slots 38,58 from the valve component 14 would allow the flowable material flowing in the hollow bore 16 to push against the valve member to force the valve member from the valve open position 62 to the valve closed position 66.

(40) Rotating the shaft 32 to drive the drive member 28 to move from the first end of the first guide slot portion 42 to the second end of the first guide slot portion 42 causes the valve member to rotate 90° about the pivot sleeve 56. When the drive member 28 is at the point of connection 50 between the second end of the first guide slot portion 42 and the first end of the second guide slot portion 44, the valve member is in a valve intermediate position 64 in which the flap portion 20 is parallel with the cross-section of the hollow bore 16 of the valve housing 12 and separated by a gap from the seal 18. This partially closes the hollow bore 16 of the valve housing 12.

(41) Further rotating the shaft 32 to drive the drive member 28 to move from the first end of the second guide slot portion 44 to the second end of the second guide slot portion 44 causes the valve member to linearly move relative to the pivot aperture 52 and towards the seal 18. When the drive member 28 is at the second end of the second guide slot portion 44 (i.e. the second terminating end 48 of the guide slot 38), the valve member is in a valve closed position 66 in which the flap portion 20 is parallel with the cross-section of the hollow bore 16 of the valve housing 12 and sealingly engages the seal 18. This closes the hollow bore 16 of the valve housing 12 and thereby prevents the flowable material from flowing along the hollow bore 16 of the valve housing 12 and therefore the hollow bore of the connected pipeline.

(42) The provision of the valve control mechanism in the valve component 14 allows operation of the drive member 28 to linearly move the valve member against the seal 18 to further compress the seal 18. This is particularly useful in circumstances when the seal 18 transitions from a hard state to a soft state whilst it is warming up, e.g. from cryogenic temperatures to atmospheric temperatures. In addition, the speed at which the valve member is linearly moved between the valve intermediate position 64 and the valve closed position 66 may be varied to correspond to the rate of transition of the seal 18 from its hard state to its soft state, so as to ensure maximum compressibility of the seal 18 and thereby enhanced sealing of the hollow bore 16. In contrast, configuring the drive member 28 to be operable to only rotate the valve member between the valve open position 62 and the valve closed position 66 might result in poor compression of the seal 18, thus resulting in an ineffectively sealed hollow bore 16.

(43) The hollow bore 16 of the valve housing 12 is re-opened by linearly moving the valve member from the valve closed position 66 to the valve intermediate position 64 and then rotating the valve member from the valve intermediate position 64 to the valve open position 62 through operation of the shaft 32 to drive the drive member 28 to move along the guide slot 38 in the opposite direction from the second terminating end 48 of the guide slot 38 to the first terminating end 46 of the guide slot 38.

(44) In this manner the valve member is movable between the valve open position 62 and the valve closed position 66, and the drive member 28 is operable to rotate the valve member between the valve open position 62 and the valve intermediate position 64 and to linearly move the valve member between the valve intermediate position 64 and the valve closed position 66.

(45) During the process of closing the hollow bore 16 of the valve housing 12, the drive member 28 is operated to directly control the speed at which the valve member is rotated between the valve open position 62 and the valve intermediate position 64 and the speed at which the valve member is linearly moved between the valve intermediate position 64 and the valve closed position 66 to provide a gradual closure of the hollow bore 16 of the valve housing 12. The speed at which the valve member moves from the valve open position 62 to the valve closed position 66 to provide a gradual closure of the hollow bore 16 of the valve housing 12 may vary depending on the type of flowable material flowing in the hollow bore 16 and its flow rate. The gradual closure of the hollow bore 16 of the valve housing 12 causes a gradual change in flow velocity of the flowable material in the hollow bore 16 of the valve housing 12 and thereby minimizes the risk of occurrence of a surge pressure in the connected pipeline that could damage the pipeline and other components connected to the pipeline.

(46) In this manner the drive member 28 is operable to vary the speed at which the valve member is rotated between the valve open position 62 and the valve intermediate position 64 and to vary the speed at which the valve member is linearly moved between the valve intermediate position 64 and the valve closed position 66.

(47) The provision of the valve control mechanism in the valve component 14 therefore results in a valve 10 that enhances the reliability and lifetime of the pipeline and other components connected to the pipeline.

(48) In addition the interaction between the drive members 28 and the guide and cam slots 58 not only ensures proper operation of the drive member 28 to move the valve member between the valve open position 62 and the valve closed position 66, thus improving the reliability of the valve component 14, but also enables operation of the drive member 28 solely through application of rotary motion to the shaft 32 (and therefore to the cams 34), thus simplifying the operation of the valve component 14.

(49) Furthermore the arrangement of the various components of the valve component 14 results in a compact arrangement of the valve component 14 without hindering the operation of the drive member 28 to move the valve member between the valve open position 62 and the valve closed position 66.

(50) It is envisaged that, in other embodiments of the invention, the valve may be a unidirectional valve.

(51) It is also envisaged that, in other embodiments of the invention, the compressible seal may be replaced by a non-compressible seal.

(52) A valve according to a second embodiment of the invention is shown in FIGS. 8a to 8f and is designated generally by the reference numeral 110. The valve 110 of FIGS. 8a to 8f is similar in structure and operation to the valve 10 of FIGS. 1a to 1c, and like features share the same reference numerals.

(53) The structure of the valve component 14 is shown in FIGS. 9 to 13.

(54) The valve component 14 includes a valve member and a valve control mechanism. The valve member includes a flap portion 20 and a flap portion support 68.

(55) The flap portion 20 is shaped in the form of a disc. The flap portion 20 includes an annular groove extending about its perimeter, where a seal 18 is located inside the annular groove. The diameter of the flap portion 20 is sized so that the seal 18 is capable of sealingly engaging a valve seat of the valve housing 12 to close the hollow bore 16 of the valve housing 12. Preferably the diameter of the flap portion 20 is 4, 6, 8, 10 or 12 inches.

(56) The valve member further includes a pair of parallel stem portions 22 that project perpendicularly from a circular surface of the flap portion support 68. Each stem portion 22 includes proximal and distal ends 22a,22b. The proximal end 22a defines the point of attachment between each stem portion 22 and the flap portion support 68. The distal end 22b defines the furthest point of each stem portion 22 away from the flap portion support 68. Each stem portion 22 includes an internally threaded aperture 24 located near the distal end 22b of the stem portion 22. Each stem portion 22 further includes a valve member slot 26 that extends along the stem portion 22 between the aperture and the proximal end 22a of the stem portion 22. Each valve member slot 26 is shaped to define a linear slot.

(57) The flap portion 20 is operably mounted on the flap portion support 68 to permit movement of the flap portion 20 relative to the flap portion support 68. More specifically, disc springs 70 in the form of Belleville washers are housed inside an internal annular cavity formed between the flap portion 20 and the flap portion support 68, where the disc springs 70 can be compressed by bringing the flap portion 20 and the flap portion support 68 towards each other. In this way the flap portion 20 forms a floating structure relative to the flap portion support 68.

(58) It is envisaged that, in other embodiments of the invention, the disc springs 70 may be replaced by a different type of compressible biasing member, preferably a spring member.

(59) The valve control mechanism includes a drive member 28, a guide element 30, a projecting member 32 and a cam 34. The projecting member 32 is in the form of a shaft but may be an axle or rod in other embodiments.

(60) The drive member 28 is in the form of a shoulder bolt that is screwed into the internal thread of the threaded aperture 24 of each stem portion 22.

(61) The guide element 30 is in the form of a mounting bracket 30 that includes a pair of opposing walls 36, each of which includes a guide slot 38. The mounting bracket 30 further includes a base 40 that interconnects the pair of opposing walls 36 and is secured to a wall of the valve housing 12.

(62) The valve member, drive member 28 and guide element 30 are arranged so that the stem portions 22 of the valve member are located between the pair of opposing walls 36, and the drive member 28 extends through the guide slot 38 of each opposing wall 36.

(63) The guide slot 38 in each opposing wall 36 includes first and second guide slot portions 42,44. The first guide slot portion 42 is shaped to define a one-quarter arcuate guide slot portion. The second guide slot portion 44 is shaped to define a linear guide slot portion. Each guide slot portion 42,44 includes first and second ends. For each guide slot 38, the first end of the first guide slot portion 42 defines a first terminating end 46 of the guide slot 38, the second end of the guide slot portion defines a second terminating end 48 of the guide slot 38, and the second end of the first guide slot portion 42 is continuously connected to the first end of the second guide slot portion 44 to define a point of connection 50 between the second end of the first guide slot portion 42 and the first end of the second guide slot portion 44.

(64) Each opposing wall 36 further includes a pivot aperture 52. The shaft 32 extends through the pivot apertures 52 and through pivot bushes 54 respectively mounted in the pivot apertures 52. The pivot bushes 54 respectively extend through the valve member slots 26 in the stem portions 22 of the valve member. The pivot bushes 54 are sized and shaped so that the valve member is rotatable about the pivot bushes 54 and so that each pivot bush 54 is linearly movable along the length of the corresponding valve member slot 26.

(65) The relative positions of the first guide slot portion 42 and pivot aperture 52 in each opposing wall 36 are arranged so that the movement of the drive member 28 along the first guide slot portion 42 causes rotation of the valve member about the pivot bushes 54. In this manner the valve member is pivotally mounted onto the mounting bracket 30.

(66) The relative positions of the second guide slot portion 44 and pivot aperture 52 in each opposing wall 36 are arranged so that the movement of the drive member 28 along the second guide slot portion 44 causes linear movement of the valve member relative to the pivot bushes 54 and towards the valve seat of the valve housing 12.

(67) The cam 34 is in the form of a cam plate and is mounted onto the shaft 32 so that the cam 34 is located between the stem portions 22 of the valve member so as to be flanked by the stem portions 22.

(68) The cam 34 includes a cam slot 58 through which the drive member 28 extends. The drive member 28 further extends through cam bushes 60 mounted in the cam slot 58 and cam bushes 60 mounted in the guide slots 38. The cam slot 58 is shaped so that the rotation of the cam 34 drives the drive member 28 to move back and forth along each guide slot 38 between its terminating ends 46,48. The interaction of the cam 34 and drive member 28 in this manner permits a rotary motion applied to the shaft 32 to be converted by the cam 34 into a combination of rotary and linear motion that is required to drive the drive member 28 along each guide slot 38.

(69) In the embodiment shown, the cam slot 58 is shaped to define a crescent-shaped cam slot 58 that defines a first recess 72 at a first end and a second recess 74 at a second end. The first recess 72 receives the drive member 28 when the drive member 28 is at the first terminating end 46 of each guide slot 38. The second recess 74 receives the drive member 28 when the drive member 28 is at the second terminating end 48 of each guide slot 38.

(70) The shaft 32 further extends through a wall of the valve housing 12 so that it can be externally rotated from the exterior of the valve housing 12. The shaft 32 may be rotated by hand or machine.

(71) The valve component further includes a retention device that is mounted on a wall of the valve housing and extends through the base 40. The retention device includes an engagement member 76 and a spring member 78. The engagement member 76 is in the form of a protrusion with a concave engagement surface. The spring member 78 is arranged between the engagement member 76 and the wall of the valve housing 12 so that the engagement member 76 forms a floating structure relative to the wall of the valve housing 12.

(72) When the cam 34 is rotated so that the drive member 28 is at the first terminating end 46 of each guide slot 38, a convex surface of the cam 34 enters into mating engagement with the concave engagement surface of the engagement member 76. In turn the spring member 78 becomes compressed and thereby applies a biasing force to the engagement member 76 so as to urge the engagement member 76 towards the cam 34. At the same time the first recess 72 of the cam slot 34 receives the drive member 28.

(73) Operation of the valve 110 is described as follows, with reference to FIGS. 14a to 14c.

(74) When the drive member 28 is located at the first end of the first guide slot portion 42 (i.e. the first terminating end 46 of each guide slot 38), the valve member is in a valve open position 62 in which the flap portion 20 is perpendicular to the cross-section of the hollow bore 16 of the valve housing 12 (i.e. the flap portion 20 bisects the hollow bore 16 of the valve housing 12). This opens the hollow bore 16 of the valve housing 12 and thereby permits the flowable material to flow along the hollow bore 16 of the valve housing 12 and therefore the hollow bore of the connected pipeline. The configuration of the valve member as a flap portion 20 that bisects the hollow bore 16 of the valve housing 12 in the valve open position 62 minimizes the resistance to the flow of the flowable material through the hollow bore 16 of the valve housing 12.

(75) In the valve open position 62 of the valve member, the compressed spring member 78 urges the engagement member 76 into mating engagement with the cam 34 while the first recess 72 of the cam slot 34 receives the drive member 28. This helps to locate the cam 34 and drive member 28 in order to resist or prevent rotation of the valve member away from the valve open position 62 towards the valve intermediate position 64. This securely holds the valve member in the valve open position 62, without the need to maintain the application of a torque to the cam 34 either by hand or machine, in order to keep the valve member in the valve open position 62.

(76) Rotating the shaft 32 to drive the drive member 28 to move from the first end of the first guide slot portion 42 to the second end of the first guide slot portion 42 causes the valve member to rotate 90° about the pivot bushes 54. Due to the compressibility of the spring member 78, the cam 34 can be disengaged from the engagement member 76 upon application of a sufficiently large torque to the shaft 32. When the drive member 28 is at the point of connection 50 between the second end of the first guide slot portion 42 and the first end of the second guide slot portion 44, the valve member is in a valve intermediate position 64 in which the flap portion 20 is parallel with the cross-section of the hollow bore 16 of the valve housing 12 and separated by a gap from the valve seat. This partially closes the hollow bore 16 of the valve housing 12.

(77) Further rotating the shaft 32 to drive the drive member 28 to move from the first end of the second guide slot portion 44 to the second end of the second guide slot portion 44 causes the valve member to linearly move relative to the pivot aperture 52 and towards the valve seat. When the drive member 28 is at the second end of the second guide slot portion 44 (i.e. the second terminating end 48 of the guide slot 38), the valve member is in a valve closed position 66 in which the flap portion 20 is parallel with the cross-section of the hollow bore 16 of the valve housing 12 and sealingly engages the valve seat. This closes the hollow bore 16 of the valve housing 12 and thereby prevents the flowable material from flowing along the hollow bore 16 of the valve housing 12 and therefore the hollow bore of the connected pipeline.

(78) The provision of the valve control mechanism in the valve component 14 allows operation of the drive member 28 to linearly move the valve member against the valve seat to further compress the seal 18. This is particularly useful in circumstances when the seal 18 transitions from a hard state to a soft state whilst it is warming up, e.g. from cryogenic temperatures to atmospheric temperatures. In addition, the speed at which the valve member is linearly moved between the valve intermediate position 64 and the valve closed position 66 may be varied to correspond to the rate of transition of the seal 18 from its hard state to its soft state, so as to ensure maximum compressibility of the seal 18 and thereby enhanced sealing of the hollow bore 16. In contrast, configuring the drive member 28 to be operable to only rotate the valve member between the valve open position 62 and the valve closed position 66 might result in poor compression of the seal 18, thus resulting in an ineffectively sealed hollow bore 16.

(79) Meanwhile, as the flap portion 20 sealingly engages the valve seat, the flap portion 20 is brought into closer proximity with the flap portion support 68. The ensuing compression of the disc springs 70 result in the application of a preload that urges the flap portion 20 towards the valve seat to help close the hollow bore 16. When there is a build-up of pressure in the closed-off hollow bore 16 (e.g. during a purging process), the compressibility of the disc springs 70 permit a limited push-back of the flap portion 20 to partially open the hollow bore 16, thus providing pressure relief. Once the pressure has dropped to a safe level, the disc springs 70 acts to bias the flap portion 20 to fully reclose the hollow bore 16.

(80) In the valve closed position 66 of the valve member, the second recess 74 receives the drive member 28 so that the second recess 74 locates the drive member 28 to resist or prevent linear movement of the valve member away from the valve closed position 66 towards the valve intermediate position 64. This securely holds the valve member in the valve closed position 66, without the need to maintain the application of a torque to the cam 34 either by hand or machine, in order to keep the valve member in the valve closed position 66. Hence, the valve member is maintained in the valve closed position 66 even when a pushing force is applied to the flap portion 20 as a result of flowing flowable material or pressure build-up.

(81) The hollow bore 16 of the valve housing 12 is re-opened by linearly moving the valve member from the valve closed position 66 to the valve intermediate position 64 and then rotating the valve member from the valve intermediate position 64 to the valve open position 62 through operation of the shaft 32 to drive the drive member 28 to move along the guide slot 38 in the opposite direction from the second terminating end 48 of the guide slot 38 to the first terminating end 46 of the guide slot 38.

(82) Preferences and options for a given aspect, feature or parameter of the invention should, unless the context indicates otherwise, be regarded as having been disclosed in combination with any and all preferences and options for all other aspects, features and parameters of the invention.

(83) As utilized herein with respect to numerical ranges, the terms “approximately,” “about,” “substantially,” and similar terms generally mean +/−10% of the disclosed values. When the terms “approximately,” “about,” “substantially,” and similar terms are applied to a structural feature (e.g., to describe its shape, size, orientation, direction, etc.), these terms are meant to cover minor variations in structure that may result from, for example, the manufacturing or assembly process and are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims.

(84) It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

(85) The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using a separate intervening member and any additional intermediate members coupled with one another, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic.

(86) References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below”) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.

(87) It is important to note that the construction and arrangement of the valve component as shown in the various exemplary embodiments is illustrative only. Additionally, any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein. For example, the disc spring of the exemplary embodiment shown in at least FIG. 11.sub.a may be incorporated in the valve component of the exemplary embodiment shown in at least 1a. Although only one example of an element from one embodiment that can be incorporated or utilized in another embodiment has been described above, it should be appreciated that other elements of the various embodiments may be incorporated or utilized with any of the other embodiments disclosed herein.