valve

Abstract

The present invention relates to a non-contact valve (10) having: - an upper coupling (40) between the spindle (33) and the valve member (28), wherein the upper coupling (40) comprises an upper pin (42) and an upper pin holder (44) which defines an upper pin cavity (46), wherein upper play in a direction transverse to the bore axis is present between the upper pin (42) and the upper pin cavity (46), which upper play allows the valve member (28) to move relative to the spindle (33) in said direction transverse to the bore axis, - a similar lower coupling (41), - an upper cam track (50) and at least one upper follower (52) which are located at an upper side of the valve member (28), wherein the upper cam track is connected to an upper side of the housing (12), and the follower (52) is connected to an upper side of the valve member (28), wherein the upper follower (52) is configured to move along the upper cam track (50) during rotation of the valve member (28), - a similar lower cam track (51) and at least one lower follower (53), wherein the upper cam track (50) and upper follower (52) and the lower cam track (51) and lower follower(53) are configured to move the valve member (28) toward and against the seat (60) in a final portion of the rotation from the open position to the closed position.

Description

P36570PC00 / WHA Title: Valve Field of the inventionThe present invention relates to the field of non-contact ball valves or in short non-contact valves. Non-contact valves are known.  Background of the inventionBall valves are known and widely used. A known drawback of a ball valve is that during a rotation from a closed to an open position or vice versa, the valve member continuously contacts the seat and slides along the seat. Every sliding movement may cause a scratch in the seat which may result in leakage. This often result in wear and tear of the seat after a limited number of opening and closing movements, possibly resulting in leakage. Non-contact ball valves have been proposed in the past to resolve this problem. US3515371A and US11549595B2 disclose examples of such a non-contact ball valve. This technology works and is used in practice. The technology is generally referred to as: rising stem ball valve. In this technology, the valve member is rotated 90° to the closed position and then tilted when the valve member is almost closed. The tilting prevents sliding of the valve member along the seat. However, this technology has a drawback in that the rising stem ball valve needs to be operated by a linear movement, hence the terminology “rising stem”. Many valves are actuator operated, the Rising Stem Ball Valves needs a linear actuator which is relatively heavy, relatively large and relatively expensive. In WO2019229265A1, a non-contact ball valve is proposed which works in combination with a quarter turn (rotary) movement. This ball valve is based on the idea that a part of the rotation of the stem (also called spindle or shaft in the prior art) is converted into a rotation of the valve member and a part of the rotation of the stem is converted into a displacement of the valve member against the seat. This ball valve has been produced and sold on the market. However, in the present invention it was recognized that this ball valve and the movement which it makes is complex and requires many moving parts. As a result, this valve can be vulnerable to malfunctioning and jamming. In particular the transition from a rotary movement of the valve member to a translational movement of the valve member is difficult to achieve. GB338913A discloses another ball valve. This ball valve is based on a similar idea as the ball valve of WO2019229265A1. A spindle rotates over an angle of 180 degrees. A part of this rotation, namely 90 degrees, causes a rotation of the valve member over 90 degrees, and a part of this rotation, the other 90 degrees, causes a movement of valve plates 20, 21 in the valve member against the seat. The mechanical transmission to create this movement is quite complex and comprises eccenters 11, 12, 11’, 12’, a locking mechanism 41, 44 with roller 50 and groove 51 and cam 57 and several other mechanical parts. The valve member (called the body 15) itself comprises moving parts, namely the valve plates 20, 21, which are driven inward and outward relative to the rest of the valve member. This is also a complex solution. Also, this valve requires two seats to function as a bi-directional valve. Further documents in this field which may be of interest are FR1288786, CN205298625U, JP2012237345A2, and US2008093574A1. As a side remark, the term ‘non-contact’ may be slightly misleading, because in the closed position of the valve, the valve member contacts the seat. For this reason, the term ‘friction free operating’ may be clearer, because what is prevented in these types of valves is friction between the moving valve member and the seat. Also, in practice, the valve may be ‘almost non-contact’ in the sense that a small amount of friction remains. Therefore, the term non-contact is intended to be interpreted broadly in this document.  Object of the invention It is an object of the invention to provide a non-contact ball valve which resolves at least one of the drawbacks discussed above. It is an object of the invention to provide a non-contact ball valve which is relatively sturdy and reliable and has relatively few moving parts. It is an object of the invention to provide a non-contact ball valve which can function in combination with a rotary actuator. It is an object of the invention to provide a non-contact ball valve which works as a bidirectional ball valve with only one seat. In an independent aspect, it is an object of the invention to provide a non-contact ball valve which has a double piston seat. Summary of the invention Valve with cam tracks and followersIn order to achieve at least one object, the invention provides a valve, comprising:a housing, comprising:a first port, anda second port,wherein the housing comprises a chamber which defines an inner volume (V) between the first and second port,a movable valve member positioned in the housing, wherein the valve member has a channel bore which defines a bore axis, wherein the valve member is rotatable between an open position and a closed position,a seat associated with the first or second port, wherein the seat is engaged by the movable valve member in the closed position thereof,a spindle configured to be rotated by an operating device such as a hand-held lever or an actuator in order to rotate the valve member between the open position and the closed position,an upper coupling between the spindle and the valve member, the upper coupling being configured to transfer the rotary movement of the spindle to the valve member, wherein the upper coupling comprises an upper pin and an upper pin holder which defines an upper pin cavity, wherein one of the upper pin and upper pin holder is connected to an upper side of the valve member and the other one is connected to the spindle, wherein the upper pin is accommodated in the upper pin cavity, wherein upper play in a direction transverse to the bore axis is present between the upper pin and the upper pin cavity, which upper play allows the valve member to move relative to the spindle in said direction transverse to the bore axis,a lower coupling between the valve member and the housing, the lower coupling being configured to allow the valve member to rotate relative to the housing, wherein the lower coupling comprises a lower pin and a lower pin holder which defines a lower pin cavity, wherein one of the lower pin and lower pin holder is connected to a lower side of the valve member and the other one is connected to the housing, the lower pin being accommodated in the lower pin cavity, wherein lower play in a direction transverse to the bore axis is present between the lower pin and the lower pin cavity, which lower play allows the valve member to move relative to the housing in the direction transverse to the bore axis,an upper cam track and at least one upper follower which are located at an upper side of the valve member, wherein one of the upper cam track and upper follower is connected to an upper side of the housing, the other one being connected to an upper side of the valve member, wherein the upper follower is configured to move along the upper cam track during rotation of the valve member,a lower cam track and at least one lower follower which are located at a lower side of the valve member, wherein one of the lower cam track and the lower follower is connected to a lower side of the housing, the other one being connected to a lower side of the valve member, wherein the lower follower is configured to move along the lower cam track during rotation of the valve member,wherein the upper cam track and upper follower and the lower cam track and lower follower are configured to move the valve member toward and against the seat in a final portion of the rotation from the open position to the closed position, and wherein the upper and lower cam track and the upper and lower follower are configured to move the valve member away from the seat in an initial portion of the rotation from the closed position to the open position. The present invention is based on the idea that in the final stage of the rotational movement of the valve member, the rotational movement of the valve member is combined with a translational movement of the valve member. In other words, the rotational movement and the translation movement are not separated in time, as with the devices of WO2019229265A1 and GB338913A, but are combined. The construction of the valve according to present invention is considerably simpler and more robust than the valves of the prior art. In some embodiments, wherein when seen in top view, the upper cam track comprises:a first upper track portion which has the shape of a part of a circle and has a first upper radius (R1),a second upper track portion which has a different shape than the first upper track portion and is configured to push the at least one upper follower toward the seat when the valve member approaches the closed position,a third upper track portion which has a different shape than the first upper track portion and is configured to push the at least one upper follower away from the seat when the valve member just leaves the closed position,and wherein the lower cam track comprises:a first lower track portion which has the shape of a part of a circle and has a first lower radius (R1),a second lower track portion which has a different shape than the first lower track portion and is configured to push the at least one lower follower toward the seat when the valve member approaches the closed position,a third lower track portion which has a different shape than the first lower track portion and is configured to push the at least one lower follower away from the seat when the valve member just leaves the closed position.It was found that this is a simple and effective way of achieving the desired movement of the valve member. The pushing action towards the seat and the pushing action away from the seat are reliable and effective.In some embodiments:in case the cam tracks are connected to the housing, the second upper and lower track portion - when seen in top view - are located at a respective first upper and lower distance (D1, D1) closer to the seat than an associated virtual continuation of the first upper and lower track portion, and wherein when seen in top view the third upper and lower track portion are located at a respective second upper and lower distance (D2, D2) closer to the seat than an associated virtual continuation of the first upper and lower track portion, andin case the cam tracks are connected to the valve member, the second upper and lower track portion - when seen in top view and when the valve member is in the closed position - are located at a respective first upper and lower distance further away from the seat than an associated virtual continuation of the first upper and lower track portion, and the third upper and lower track portion are located at a respective second upper and lower distance further away from the seat than an associated virtual continuation of the first upper and lower track portion. This is essentially amechanical inversion, and the valve member will be moved against the seat in the closed position. In some embodiments, a port axis is defined by centers (C1, C2) of the first and second ports, wherein when seen in top view the first upper and lower distance (D1, D1) increase with a decreasing distance between the at least one follower and the port axis. In some embodiments, when at least one upper and lower follower move along respectively the second upper and lower track portion, the valve member moves toward the seat while rotating from the open to the closed position and wherein when the at least one upper and lower follower move along respectively the third upper and lower track portion, the valve member moves away from the seat while rotating from the closed to the open position. The combined movement makes a simple and robust construction of the valve possible. In some embodiments, the one of the lower pin and lower pin holder which is connected to the housing, is rotatably connected to the housing. In some embodiments, the upper and lower cam track are connected to the housing and wherein the at least one upper and lower followers are connected to the valve member wherein the valve comprises two lower followers which are rounded projections which project from a circumferential outer wall of the lower pin holder and wherein the valve comprises two upper followers which are rounded projections which project from a circumferential outer wall of the upper pin holder. It was found that this results in a sturdy construction. In some embodiments, the upper and lower pin holder are connected to the valve member, wherein the upper pin is connected to the spindle and the lower pin is rotatably connected to the housing. It was found that this results in a sturdy construction. In some embodiments, the valve member comprises a valve member rotation axis which extends between:an upper center of the one of the upper pin and upper pin cavity holder which is connected to the upper side of the valve member anda lower center of the one of the lower pin and lower pin cavity holder which is connected to lower side of the valve member,wherein the upper and lower play allow a movement of the valve member rotation axis of the valve member relative to the spindle axis, such that:in the open position of the valve member, the valve member rotation axis is aligned with the spindle axis, andin the closed position of the valve member, the valve member rotation axis is located at a distance from the spindle axis, wherein the valve member rotation axis is located closer to the seat. In some embodiments, the valve member rotation axis is parallel to the spindle axis in the closed position of the valve member, and in particular also in any position of the valve member between the open and closed position. The parallel orientation enables a well defined movement of the valve member. In some embodiments, when seen in top view the valve member rotation axis moves along an axis trajectory between an aligned position which is associated with the open position of the valve member, in which aligned position the valve member rotation axis is aligned with the spindle axis, and an off-center position which is associated with the closed position of the valve member and in which the valve member rotation axis is offset relative to the spindle axis, wherein when seen in top view the off-center position is located on the port axis. In some embodiments, the valve member comprises an annular contact part which is configured to contact the seat in the closed position of the valve member. In some embodiments, the upper pin cavity has an upper cavity width and an upper cavity length, wherein a cross-section of the upper pin has an upper pin width and an upper pin length, wherein the upper cavity width matches the upper pin width in that no play is present between them and wherein the upper cavity length is greater than the upper pin length thereby providing said upper play, andwherein the lower pin cavity has a lower cavity width and a lower cavity length, wherein a cross-section of the lower pin has a lower pin width and a lower pin length, wherein the lower cavity width matches the lower pin width in that no play between them is present and wherein the lower cavity length is greater than the lower pin length, thereby providing said lower play, andwherein the upper and lower pin cavity have opposing longitudinal sides which define the length of the upper and lower pin cavity, and wherein the upper and lower pin have longitudinal sides, allowing the upper pin to slide relative to the upper pin cavity and the lower pin to slide relative to the lower pin cavity. This construction is sturdy and allows a welldefined sliding movement of the valve member and consequently a welldefined movement of the valve member rotation axis. In some embodiments, a rotation of the spindle causes a same rotation of the valve member over the entire range of rotation of the spindle between the open and the closed position, such that the valve member does not rotate relative to the spindle. This allows a simple construction of the valve. In some embodiments, when seen in top view a direction of play of the upper and lower pin relative to the upper and lower pin holder is oriented transverse to the bore axis, and in particular oriented at an angle of 80-100 degrees to the bore axis, more in particular at right angles, i.e. 90 degrees, to the bore axis. In some embodiments, the upper and lower cam track are annular and when seen in top view extend around respectively the upper and lower pin holder. This allows a simple construction and fabrication of the upper and lower cam track.In some embodiments, when seen in top view the upper and lower cam track have a same shape. This creates a welldefined movement of the valve member. In some embodiments, the valve member does not comprise any part which moves relative to another part of the valve member. This results in overall simplicity of construction. In some embodiments, the valve comprises:a first upper follower and a second upper follower, wherein when seen in top view the first and second upper follower are placed at a circumferential angle of 160-200 degrees about the valve member rotation axis, in particular at a circumferential angle of 180 degrees, relative to one another,a first lower follower and a second lower follower, wherein when seen in top view the first and second lower follower are placed at a circumferential angle of 160-200 degrees, in particular at a circumferential angle of 180 degrees, about the valve member rotation axis relative to one another.It was found that the double followers enable a simple construction of the cam tracks. In some embodiments, the upper and lower pin holder are connected to the valve member, wherein the first and second upper follower are formed on an outer side of the upper pin holder and wherein the first and second lower follower are formed on an outer side of the lower pin holder, and wherein the upper and lower cam track are located outwardly of respectively the upper and lower pin holder. This was found to be an efficient way of arranging the different parts. It also allows an accurate movement of the valve member. In some embodiments, the housing comprises a seat assembly (herein also referred to as: seat) which is associated with the first or second port, and a downstream seat stop and an upstream seat stop which are associated with the seat assembly, the seat assembly comprising:a seat ring defining a seat opening, wherein the seat ring is movably arranged in the housing, the seat ring being movable between un upstream seat position in which the seat ring abuts the upstream seat stop and a downstream seat position in which the seat ring abuts the downstream seat stop,a seat member, integral with or connected to the seat ring, the seat member being engaged by the movable valve member in the closed position thereof,a number of biasing members, which are in particular springs, and which exert a force on the seat ring in an upstream direction,a double piston mechanism comprising:a seal cavity defined between the seat ring and the housing, the seal cavity being limited on a downstream end thereof by a downstream cavity stop formed by the housing and limited on an upstream end thereof by an upstream cavity stop formed by the seat ring,a seal located in the seal cavity, wherein the seal is movable relative to the seat ring between the downstream and upstream cavity stop,an upstream channel which extends from an upstream side of the seat assembly to the seal cavity,a downstream channel which extends from a downstream side of the seat assembly to the seal cavity,wherein when the valve member is in the closed position: when a downstream fluid pressure is higher than an upstream fluid pressure, the seal moves against the upstream cavity stop and a net force is created on the seat ring which presses the seat member against the valve member and wherein when an upstream fluid pressure is higher than a downstream fluid pressure, the seal moves against the downstream cavity stop and a net force is created on the seat ring which presses the seat member against the valve member, andwherein when the valve member is in the open position the seat ring is pressed against the upstream seat stop by the biasing members.A double piston seat in itself is known. However, a double piston seat is typically unable to work with a non-contact ball valve because it needs to be in contact with the valve member to work properly. This problem has been resolved with the addition of the upstream seat stop, which keeps the seat in place when the valve member is in the open position in which it is retracted from the seat and not in contact with the seat. Further embodimentIn a further embodiment, the present invention relates to a valve (10), comprising:a housing, comprising:a first port, anda second port,wherein the housing comprises a chamber which defines an inner volume between the first and second port,a movable valve member positioned in the housing, wherein the valve member has a channel bore which defines a bore axis, wherein the valve member is rotatable about a valve member rotation axis between an open position and a closed position,a seat associated with the first or second port, wherein the seat is engaged by the movable valve member in the closed position thereof,a spindle configured to be rotated about a spindle axis by an operating device such as a hand-held lever or an actuator in order to rotate the valve member between the open position and the closed position,a first coupling between the spindle and the valve member, the first coupling being configured to transfer the rotary movement of the spindle to the valve member, wherein the first coupling allows the valve member to move relative to the spindle over a distance in a direction transverse to the bore axis and transverse to the valve member rotation axis,a first cam track and at least one first follower, wherein one of the first cam track and first follower is connected to the housing, the other one being connected to the valve member, wherein the first follower is configured to move along the first cam track during rotation of the valve member,wherein the first cam track and the at least one first follower are configured to move the valve member toward and against the seat in a final portion of the rotation from the open position to the closed position, and wherein the first track and the first follower are configured to move the valve member away from the seat in an initial portion of the rotation from the closed position to the open position. It was recognized that the valve may work with a single coupling and a single cam track with follower(s). The single coupling couples the rotation of the valve member to the rotation of the spindle and allows a movement of the valve member rotation axis relative to the spindle rotation axis in a direction transverse to the bore axis. The single cam track forces the valve member along the prescribed trajectory. For this configuration to work, it is required that any rotation of the valve member relative to the housing other than the rotation about the valve member rotation axis is prevented. This may be realized with a first coupling comprising a track and traveller instead of a cavity and a pin, the track being connected to the spindle and the traveller being connected to the valve member, or vice versa. The traveller may have only a single freedom of rotation relative to the track, namely a translation in the direction of the track. It may also be realized by having a single coupling and a first and second cam track with respective followers. It may also be realized by a first and second coupling and a single cam track. The first and second coupling prevent any rotation of the valve member other than the rotation about the valve member rotation axis and the single cam track controls the translation of the valve member toward and away from the seat. It was further recognized that if a second cam track is present, the first and second cam track and the first and second follower can both be positioned above the valve member, i.e. on the side of the valve member where the spindle is, or both be positioned below the valve member, i.e. on the other side of the valve member than the spindle. Although this may have a disadvantageous effect that the housing and the valve as a whole becomes more bulky, it results in a functioning valve. It was realized that the freedom of movement in a direction transverse to the bore axis (when seen in top view) can be realized with a single coupling comprising a cavity and a pin, but also with a single coupling comprising a track and a traveller. The track may be connected to the spindle and the traveller may be connected to the valve member or vice versa. In top view, the track extends transverse to the bore axis. In some embodiments, the first cam track and first follower and the second cam track and second follower form a fixed-moment construction between the housing and the valve member which prevents a rotation of the valve member relative to the housing about any axis which is different from the valve member rotation axis. By forming a fixed moment construction between the housing and the valve member, the freedom of movement of the valve member is limited to a rotation about the valve member rotation axis plus a shift over a horizontal distance toward and away from the seat. In some embodiments, the valve comprises a second cam track and at least one second follower, wherein the second cam track and second follower are positioned at a distance in the direction of the valve member rotation axis from the first cam track and first follower, wherein one of the second cam track and the second follower is connected to the housing, the other one being connected to the valve member, wherein the second follower is configured to move along the second cam track during rotation of the valve member,wherein the first cam track and first follower and the second cam track and second follower are configured to move the valve member toward and against the seat in a final portion of the rotation from the open position to the closed position, and wherein the first and second cam track and the first and second follower are configured to move the valve member away from the seat in an initial portion of the rotation from the closed position to the open position. In some embodiments, the first coupling between the spindle and the valve member is an upper coupling, wherein the upper coupling comprises an upper pin and an upper pin holder which defines an upper pin cavity, wherein one of the upper pin and upper pin holder is connected to an upper side of the valve member and the other one is connected to the spindle, wherein the upper pin is accommodated in the upper pin cavity, wherein upper play in a direction transverse to the bore axis is present between the upper pin and the upper pin cavity, which upper play allows the valve member to move relative to the spindle in said direction transverse to the bore axis, or wherein the first coupling comprises a track and traveller, the track connected to the spindle and the traveller connected to the valve member or vice versa, wherein the track extends in a direction transverse to the bore axis and transverse to the valve member rotation axis. In some embodiments, the valve comprises a second coupling between the valve member and the housing or between the valve member and the spindle, the second coupling being configured to allow the valve member to rotate relative to the housing, wherein the second coupling allows the valve member to move relative to the housing in the direction transverse to the bore axis and transverse to the valve member rotation axis. In some embodiments, the second coupling is a lower coupling between the valve member and the housing, the lower coupling being configured to allow the valve member to rotate relative to the housing, wherein the lower coupling comprises a lower pin and a lower pin holder which defines a lower pin cavity, wherein one of the lower pin and lower pin holder is connected to a lower side of the valve member and the other one is connected to the housing, the lower pin being accommodated in the lower pin cavity, wherein lower play in a direction transverse to the bore axis is present between the lower pin and the lower pin cavity, which lower play allows the valve member to move relative to the housing in the direction transverse to the bore axis,orthe second coupling comprises a track and traveller, the track connected to the housing and the traveller connected to the valve member or vice versa, wherein the track extends in a direction transverse to the bore axis and transverse to the valve member rotation axis.  In some embodiments, the first cam track is an upper cam track and the first follower is an upper follower which are located at an upper side of the valve member, wherein one of the upper cam track and upper follower is connected to an upper side of the housing, the other one being connected to an upper side of the valve member, wherein the upper follower is configured to move along the upper cam track during rotation of the valve member, andwherein the second cam track is a lower cam track and wherein the second follower is a lower follower which are located at a lower side of the valve member, wherein one of the lower cam track and the lower follower is connected to a lower side of the housing, the other one being connected to a lower side of the valve member, wherein the lower follower is configured to move along the lower cam track during rotation of the valve member. In some embodiments, when seen in top view, the first, upper cam track comprises:a first upper track portion which has the shape of a part of a circle and has a first upper radius (R1),a second upper track portion which has a different shape than the first upper track portion and is configured to push the at least one upper follower toward the seat when the valve member approaches the closed position,a third upper track portion which has a different shape than the first upper track portion and is configured to push the at least one upper follower away from the seat when the valve member just leaves the closed position,and wherein the second, lower cam track comprises:a first lower track portion which has the shape of a part of a circle and has a first lower radius (R1),a second lower track portion which has a different shape than the first lower track portion and is configured to push the at least one lower follower toward the seat when the valve member approaches the closed position,a third lower track portion which has a different shape than the first lower track portion and is configured to push the at least one lower follower away from the seat when the valve member just leaves the closed position. In some embodiments:in case the cam tracks are connected to the housing, the second upper and lower track portion - when seen in top view - are located at a respective first upper and lower distance (D1, D1) closer to the seat than an associated virtual continuation of the first upper and lower track portion, and wherein when seen in top view the third upper and lower track portion are located at a respective second upper and lower distance (D2, D2) closer to the seat than an associated virtual continuation of the first upper and lower track portion, andin case the cam tracks are connected to the valve member, the second upper and lower track portion - when seen in top view and when the valve member is in the closed position - are located at a respective first upper and lower distance further away from the seat than an associated virtual continuation of the first upper and lower track portion, and the third upper and lower track portion are located at a respective second upper and lower distance further away from the seat than an associated virtual continuation of the first upper and lower track portion. In some embodiments, a port axis is defined by centers (C1, C2) of the first and second ports, wherein when seen in top view the first upper and lower distance (D1, D1) increase with a decreasing distance between the at least one follower and the port axis. In some embodiments, when the first and second upper and lower follower move along respectively the second upper and lower track portion, the valve member moves toward the seat while rotating from the open to the closed position and wherein when the at least one upper and lower follower move along respectively the third upper and lower track portion, the valve member moves away from the seat while rotating from the closed to the open position. In some embodiments, the one of the lower pin and lower pin holder which is connected to the housing, is rotatably connected to the housing. In some embodiments, the first, upper cam track and second, lower cam track are connected to the housing and wherein the at least one first, upper followers and second, lower followers are connected to the valve member, wherein the valve comprises two lower followers which are in particular rounded projections from a circumferential outer wall of the lower pin holder and wherein the valve comprises two upper followers which are rounded projections from a circumferential outer wall of the upper pin holder . In some embodiments, the upper and lower pin holder are connected to the valve member, wherein the upper pin is connected to the spindle and the lower pin is rotatably connected to the housing. In some embodiments, the valve member rotates about a valve member rotation axis and wherein the spindle rotates about a spindle axis, and wherein in the open position of the valve member, the valve member rotation axis is aligned with the spindle axis, and in the closed position of the valve member, the valve member rotation axis is located at a distance from the spindle axis, wherein the valve member rotation axis is located closer to the seat. In some embodiments, the valve member rotation axis is parallel to the spindle axis in the closed position of the valve member, and in particular also in any position of the valve member between the open and closed position. In some embodiments, when seen in top view the valve member rotation axis moves along an axis trajectory between an aligned position which is associated with the open position of the valve member and an off-center position which is associated with the closed position of the valve member, wherein when seen in top view the off-center position is located on the port axis. In some embodiments, the valve comprises an annular contact part which is configured to contact the seat in the closed position of the valve member, wherein when seen in top view the contact part approaches the seat in an approach direction which extends at an angle of between 5 and 85 degrees, in particular 30-60 degrees with the port axis. In some embodiments, the upper pin cavity has an upper cavity width and an upper cavity length, wherein a cross-section of the upper pin has an upper pin width and an upper pin length, wherein the upper cavity width matches the upper pin width in that no play is present between them and wherein the upper cavity length is greater than the upper pin length thereby providing said upper play, andwherein the lower pin cavity has a lower cavity width and a lower cavity length, wherein a cross-section of the lower pin has a lower pin width and a lower pin length, wherein the lower cavity width matches the lower pin width in that no play between them is present and wherein the lower cavity length is greater than the lower pin length, thereby providing said lower play, andwherein the upper and lower pin cavity have opposing longitudinal sides which define the length of the upper and lower pin cavity, and wherein the upper and lower pin have longitudinal sides, allowing the upper pin to slide relative to the upper pin cavity and the lower pin to slide relative to the lower pin cavity. In some embodiments, the first coupling rotationally fixes the valve member to the spindle such that a rotation of the spindle causes a same rotation of the valve member over the entire range of rotation of the spindle between the open and the closed position, wherein the valve member does not rotate relative to the spindle. In some embodiments, when seen in top view a direction of play of the upper and lower pin relative to the upper and lower pin holder is oriented transverse to the bore axis, and in particular oriented at an angle of 80-100 degrees to the bore axis, more in particular at right angles to the bore axis. In some embodiments, the first, upper and second lower cam track are annular and when seen in top view extend around the valve member rotation axis. In some embodiments, when seen in top view the upper and lower cam track have a same shape. In some embodiments, the valve member does not comprise any part which moves relative to another part of the valve member. In some embodiments, the housing comprises a seat assembly which is associated with the first or second port, and a downstream seat stop and an upstream seat stop associated with the seat assembly, wherein the seat assembly comprises:a seat ring defining a seat opening, wherein the seat ring is movably arranged in the housing, the seat ring being movable between an upstream seat position in which the seat ring abuts the upstream seat stop and a downstream seat position in which the seat ring abuts the downstream seat stop,a seat member, integral with or connected to the seat ring, the seat member being engaged by the movable valve member in the closed position thereof,a number of biasing members, which are in particular springs, and which exert a force on the seat ring in an upstream direction,a double piston mechanism comprising:a seal cavity defined between the seat ring and the housing, the seal cavity being limited on a downstream end thereof by a downstream cavity stop formed by the housing and limited on an upstream end thereof by an upstream cavity stop formed by the seat ring,a seal located in the seal cavity, wherein the seal is movable relative to the seat ring between the downstream and upstream cavity stop,an upstream channel which extends from an upstream side of the seat assembly to the seal cavity,a downstream channel which extends from a downstream side of the seat assembly to the seal cavity,wherein when the valve member is in the closed position and a downstream fluid pressure is higher than an upstream fluid pressure, the seal moves against the upstream cavity stop and a net force is created on the seat ring which presses the seat member against the valve member, andwherein when the valve member is in the closed position and an upstream fluid pressure is higher than a downstream fluid pressure, the seal moves against the downstream cavity stop and a net force is created on the seat ring which presses the seat member against the valve member, andwherein when the valve member is in the open position, the seat ring is pressed against the upstream seat stop by the biasing members. NON-CONTACT BALL VALVE WITH DOUBLE PISTON SEAT In an independent aspect, the present invention relates to a non-contact ball valve, comprising:a housing, comprising:a first port,a second port,a downstream seat stop and an upstream seat stop associated with the first or second port,wherein the housing comprises a chamber which defines an inner volume (V) between the first and second port, and wherein a port axis is defined by a centre of the first port and a centre of the second port,a movable valve member positioned in the housing, wherein the valve member has a channel bore which defines a bore axis, wherein the valve member is rotatable between an open position and a closed position,a spindle configured to be rotated by an operating device such as a lever or an actuator in order to move the valve member between the open and closed position, or a rising stem configured to be moved up and down in order to move the valve member between the open and closed position,a seat assembly associated with the first or second port, the seat assembly comprising:a seat ring defining a seat opening, wherein the seat ring is movably arranged in the housing, the seat ring being movable between an upstream seat position in which the seat ring abuts the upstream seat stop and a downstream seat position in which the seat ring abuts the downstream seat stop,a seat member, integral with or connected to the seat ring, the seat member being engaged by the movable valve member in the closed position thereof,a number of biasing members, which are in particular springs, and which exert a force on the seat ring in an upstream direction,a double piston mechanism comprising:a seal cavity defined between the seat ring and the housing, the seal cavity being limited on a downstream end thereof by a downstream cavity stop formed by the housing and limited on an upstream end thereof by an upstream cavity stop formed by the seat ring,a seal located in the seal cavity, wherein the seal is movable relative to the seat ring between the downstream and upstream cavity stop,an upstream channel which extends from an upstream side of the seat assembly to the seal cavity,a downstream channel which extends from a downstream side of the seat assembly to the seal cavity,wherein when a downstream fluid pressure is higher than an upstream fluid pressure, the seal moves against the upstream cavity stop and a net force is created on the seat ring which presses the seat member against the valve member and wherein when an upstream fluid pressure is higher than a downstream fluid pressure, the seal moves against the downstream cavity stop and a net force is created on the seat ring which presses the seat member against the valve member,a non-contact mechanism which causes the valve member to:have a component of movement in the direction of the port axis and toward the seat member in a final portion of a movement of the valve member from the open position to the closed position thereof and,have a component of movement in the direction of the port axis and away from the seat member in an initial portion of a movement of the valve member from the closed position thereof to the open position,wherein the non-contact mechanism prevents the valve member from sliding against the seat member during the final portion respectively initial portion of movement, andwherein when the valve member is in the open position the seat ring is pressed against the upstream seat stop by the biasing members. A double piston seat in itself is known. However, it was recognized in the present invention that a double piston seat is typically unable to work with a non-contact ball valve because it needs to be in contact with the valve member continuously in order to work properly. This problem has been resolved with the addition of the upstream seat stop, which keeps the seat in place when the valve member is in the open position in which it is retracted from the seat and not in contact with the seat.In some embodiments the non-contact mechanism is:a rising stem mechanism which converts a part of a linear movement of stem into a rotation of the valve member and converts a part of a linear movement of a stem into a tilting of the valve member toward or away from the seat, e.g. as disclosed in US3515371A or US11549595B2, ora non-contact mechanism having a coupling between the spindle and the valve member, wherein the coupling converts a first portion of a rotation of the spindle into a rotation of the valve member and converts a second portion of a rotation of the spindle into a displacement of the valve member toward or away from the seat, e.g. as disclosed in WO2019 / 229265A1, ora non-contact mechanism comprising a valve member having a main body and valve plates which are movable relative to the main body, e.g. as disclosed in GB338913A, ora non-contact mechanism according to any of claims 11-31.The double piston seat of the preset invention essentially works with multiple non-contact mechanisms, and the application is not restricted to the non-contact mechanism presented in this document.The valve according to the present invention can be a single seat valve. To the best of the knowledge of the applicant, a non-contact valve having a single seat assembly with a double piston mechanism does not exist. It is noted that a double-piston mechanism is also known as a bi-directional seat. Hence, the present invention provides a non-contact valve having a single seat assembly with a bi-directional sealing function.In some embodiments, the seal cavity is formed by an L-shaped portion in an outer circumference of the seat ring and by an opposed L-shaped portion in the housing. In some embodiments, the upstream and downstream seat stop extend circumferentially around the seat. In some embodiments, the seat member is an annular metal insert.In some embodiments, the seat ring can make a stroke between the upstream seat stop and the downstream seat stop, wherein the stroke has a stroke length which depends on the size of the valve. It was found that a limited stroke length works well to allow the valve member to disengage from the seat in the open position. In some embodiments, the upstream channel is defined between the seat and the housing, and the downstream channel is defined between the seat and the housing. In some embodiments, the upstream channel and / or downstream channel extend circumferentially around the seat.These and other aspects of the invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference symbols designate like parts. Short description of the figuresFigures 1A and 1B show isometric views of a first embodiment of the invention.Figures 2A and 2B show isometric views of a second embodiment of the invention.Figures 3, 4, 5 and 6 show respectively a top view, left view, front view an right view of the first embodiment.Figure 7 shows a sectional front view of the first embodiment.Figures 8,9,11 and 12 show sectional views as indicated with respectively A-A, B-B, C-C and D-D in the side view of fig. 10.Fig. 13 shows a sectional isometric view of the valve according to the invention.Fig. 14 and 15 show a top view and an isometric view of a valve member of the valve.Figs. 16A and 16B show sectional top view of the valve in an almost closed state.Fig. 17 shows a sectional top view of the valve in a closed state.Fig. 18 shows a sectional top view of the valve in an open state.Figs. 19, 20 and 21 shows sectional detail top views of the cam track and follower in respectively an almost closed position, a closed position and an open position.Figures 22 and 23 show sectional top views of the valve member and seat in respectively an almost closed position and a closed position.Figures 24 and 25 show close-up sectional top views of the valve member and seat in respectively an almost closed position and closed position.Figure 26 shows another embodiment of the invention. Detailed description of the figuresTurning to figures 1A, 1B,3, 4, 5 and 6, the valve 10 according to the invention is shown. The valve comprises a housing 12 which comprising a first port 14, and a second port 16. The housing has a chamber 18 between the first and second port which defines an inner volume (V). In this embodiment, the valve has a hand-held lever 20 but any suitable operating device may be used. For instance, a wheel which can be manually operated may also be used. The housing comprises a top plate 22 which is secured by bolts 24 and which can be removed. The removable top plate allows installation and maintenance of the inner parts. Turning to figs. 2A and 2B. in another embodiment, the valve 10 is the same, but the hand-held lever is replaced by a rotary type actuator 26. This can be an electric, pneumatic or hydraulic actuator. Turning to fig. 7, the valve has a movable valve member 28 positioned in the housing 12. The the valve member has a channel bore 30 which defines a bore axis 32. The valve member 28 is rotatable between an open position and a closed position. Fig. 7 shows the closed position. In this embodiment the valve member 28 does not comprise any part which moves relative to another part of the valve member. The valve 10 has a spindle 33 configured to be rotated by the hand-held lever or by the actuator in order to rotate the valve member 28 between the open position and the closed position.The valve comprises a first, upper coupling 40 between the spindle 33 and the valve member 28. The first, upper coupling is configured to transfer the rotary movement of the spindle to the valve member. This coupling may be referred to as an upper coupling or as a first coupling. The first, upper coupling comprises an upper pin 42 and an upper pin holder 44 which defines an upper pin cavity 46. One of the upper pin and upper pin holder, in this case the pin holder, is connected to an upper side of the valve member. The other one, in this case the pin, is connected to the spindle. This can be inverted. The upper pin 42 is accommodated in the upper pin cavity 46. The upper pin cavity is larger than the upper pin. Upper play in a direction transverse to the bore axis 32 is present between the upper pin 42 and the upper pin cavity 46. The upper play allows the valve member 28 to move relative to the spindle 33 in said direction transverse to the bore axis.It is noted that the terms “upper” and “lower” refer to the orientation of the valve as shown in the figures, which is the most used orientation for a valve. However, the valve may be mounted in a different orientation and the skilled person will understand that some terms in this document like upper and lower would then need to be changed accordingly.The valve further comprises a lower coupling 41 between the valve member and the housing. The lower coupling is configured to allow the valve member to rotate relative to the housing 12. The lower coupling 41 comprises a lower pin 43 and a lower pin holder 45 which defines a lower pin cavity 47. In this case, the lower pin holder 45 is connected to a lower side of the valve member 28 and the lower pin 43 is connected to the housing 12 but this may be reversed. The lower pin 43 is rotary. The lower pin 43 is accommodated in the lower pin cavity 47 which is larger. Lower play 49 in a direction transverse to the bore axis 32 is present between the lower pin and the lower pin cavity. The lower play allows the valve member to move relative to the housing in the direction transverse to the bore axis.A seat assembly 60 (short: seat) is associated with the first or second port 14, 16, in this case the second port. The seat assembly 60 is engaged by the movable valve member 28 in the closed position thereof.A first, upper cam track 50 and at least one upper follower 52 are located at an upper side of the valve member 28. The cam track 50 may be referred to as the first cam track or the upper cam track. One of the upper cam track 50 and upper follower 52 is connected to an upper side of the housing 12, in this case the cam track. The other is connected to an upper side of the valve member 28, in this case the follower 52. The upper follower is configured to move along the upper cam track during rotation of the valve member.A second, lower cam track 51 and at least one lower follower 53 are located at a lower side of the valve member. The cam track 51 may be referred to as the second cam track or as the lower cam track.One of the lower cam track and the lower follower is connected to a lower side of the housing, in this case the cam track. The other one is connected to a lower side of the valve member. The lower follower is configured to move along the lower cam track during rotation of the valve member.The upper cam track 50 and upper follower 52 and the lower cam track 51 and lower follower 53 are configured to move the valve member 28 toward and against the seat assembly 60 in a final portion of the rotation from the open position to the closed position. The upper and lower cam track 50, 51 and the upper and lower follower 52, 54 are configured to move the valve member away from the seat assembly in an initial portion of the rotation from the closed position to the open position. The upper and lower cam track 50, 51 are connected to the housing 12 and the at least one upper and lower followers 52, 53 are connected to the valve member 28. When seen in top view the upper and lower cam track 50, 51 have a same shape. The upper and lower pin holder 44, 45 are connected to the valve member 28, wherein the upper pin 42 is connected to the spindle and the lower pin 43 is rotatably connected to the housing. A port axis 71 is defined by centers C1, C2 of the first and second ports 14,16, wherein when seen in top view the second upper and lower distance D2, D2 (see figure 16B) increase with decreasing distance from the port axis. Turning to figures 8 through 12, further views of the valve according to the invention are shown, wherein the valve member 28 is in the open position. In the open position, the valve member 28 does not contact the seat assembly. The spindle axis 67 and valve member rotation axis 68 are shown in figure 8. In the open position, the valve member rotation axis 68 is aligned with the spindle axis. In the closed position, the valve member rotation axis 68 is slightly offset from the spindle axis 67 as will be explained in more detail below. Turning to fig. 13, a lower part of the valve is shown. When seen in top view, the lower cam track 51 comprises:a first lower track portion 61 which has the shape of a part of a circle and has a first lower radius (R1),a second lower track portion 63 which has a different shape than the first lower track portion and is configured to push the at least one lower follower toward the seat assembly when the valve member approaches the closed position,a third lower track portion 65 which has a different shape than the first lower track portion and is configured to push the at least one lower follower away from the seat assembly the housing comprises a downstream seat stop and an upstream seat stop associated with a seat assembly when the valve member just leaves the closed position.The lower cam track 51 has an annular configuration with the second lower track portion 63 and the third lower track portion 65 at opposite positions along the annulus.Although not shown, the upper cam track has a similar configuration as the lower cam track and comprises:a first upper track portion 62 which has the shape of a part of a circle and has a first upper radius (R1),a second upper track portion 64 which has a different shape than the first upper track portion and is configured to push the at least one upper follower toward the seat assembly when the valve member approaches the closed position,a third upper track portion 66 which has a different shape than the first upper track portion and is configured to push the at least one upper follower away from the seat assembly when the valve member just leaves the closed position.The upper and lower cam track extend around respectively the upper and lower pin holder. In fig. 13, there are two lower followers 53A, 53B. The two lower followers 53A, 53B are rounded projections which project from a circumferential outer wall of the lower pin holder 45. The two lower followers 53A, 53B are placed opposite one another. Different embodiments of the cam tracks and followers are possible, however. With reference to fig. 26, a slotted cam track 51 is also possible, as the skilled person will understand. With the words “slotted cam track” a cam track in the form of a groove is meant. In the embodiment of fig. 26, there is one slotted cam track 51 which extends over a circumferential angle of 360 degrees and accommodates two followers 53A, 53B. The followers are pins which extend downward or upward into the cam track. This embodiment may be less strong than the first embodiment with the open cam track as shown in figs. 1-21, because the pins may be subject to fatigue and break off after a number of operating cycles. However, for some light applications this may still work. Other configurations of a slotted cam track are also possible. A single slotted cam track would need to extend at least over a circumferential angle of about 90-100 degrees. Two slotted cam tracks would need to extend over 90 degrees each. Various configurations are possible. In some other embodiments, there may be only one cam track with associated follower(s). In this embodiment, the valve member rotation axis 68 is maintained parallel to the spindle axis 67 by the first coupling, which may be a track and traveller. Also, in versions with a first and second coupling, these couplings may comprise a track and traveller instead of a pin and a pin cavity. In some other embodiments, the first and second cam track may both be situated above the valve member or both be situated below the valve member. Returning to figs. 13, 14 and 15, in the shown embodiment, there are also two upper followers 52A, 52B. The two upper followers 52A, 52B are rounded projections from a circumferential outer wall of the upper pin holder 44 which are opposite one another. It was found that this is a strong construction, as opposed to pins in a slotted cam track, which may break off under high loads. The projections are only put under compressive loads during operation, which reduces or eliminates the risk of mechanical overload. The first upper and lower track portion 62, 61 each have two first track portions 62, 61, one first track portion 62 respectively 61 for each upper follower 52A, 52B respectively lower follower 53A, 53B. It can also be seen in fig. 13 that a first lower follower 53A and a second lower follower 53B are provided, commonly denoted as 53. When seen in top view the first and second lower follower 53A, 53B have a mirrored position, i.e. are placed at a circumferential angle of 160-200 degrees, in particular at a circumferential angle of 180 degrees, about the valve member rotation axis 68 relative to one another. The upper followers may have have similar configuration with first and second upper follower 52A, 52B. The one of the lower pin 43 and lower pin holder 45 which is connected to the housing, in this case the lower pin holder, is rotatably connected to the housing. In case the lower pin holder 45 is connected to the housing, it is rotatably connected to the housing. In case the lower pin would be connected to the housing (this embodiment is not shown), the lower pin would be rotatably connected to the housing. In top view, a longitudinal direction of the upper pin cavity is aligned with the position of the upper followers 52. The first and second upper follower 52A, 52B are formed on an outer side of the upper pin holder 44 and wherein the first and second lower follower 53A, 53B are formed on an outer side of the lower pin holder 45. The upper and lower cam track 50, 51 are located outwardly of respectively the upper and lower pin holder.The upper and lower cam tracks, upper and lower followers, upper and lower pins and pin holders with pin cavity as described in these embodiments constitute a non-contact mechanism 100 or in other words: a friction free mechanism in which no or very little friction is present between the movable valve member and the valve seat.Turning to figures 14 and 15, the upper followers 52 may have a same or similar configuration as the lower followers 53.Turning to figures 16A and 16B, when the first upper and lower follower 52A, 53A move in a clockwise direction along respectively the second upper and lower track portion 64, 63 the valve member moves toward the seat assembly and towards the closed position while rotating and when the second upper and lower follower 52B, 53B move in a counter-clockwise direction along respectively the third upper and lower track portion 66, 65, the valve member moves away from the seat assembly and towards the open position while rotating.In figures, 16A and 16B, the valve member 28 is in the almost closed position. The arrow 29 indicates the direction of rotation to the fully closed position which is clockwise. In case the cam tracks are connected to the housing – as shown – the second upper and lower track portion 64, 63 - when seen in top view – are located at a first upper and lower distance (D1, D1) closer to the seat assembly than an associated virtual continuation 69 of the first upper and lower track portion. When seen in top view the third upper and lower track portion are located at a respective second upper and lower distance D2, D2 closer to the seat assembly than an associated virtual continuation 69, 70 (indicated in dash-dotted lines in Fig. 16B) of the first upper and lower track portion. In case the cam tracks are connected to the valve member and the followers are connected to the housing (which is a mechanical inversion which is not shown), the second upper and lower track portion - when seen in top view and when the valve member is in the closed position - are located at a respective second upper and lower distance D1, D2 further away from the seat assembly than an associated virtual continuation of the first upper and lower track portion, and the third upper and lower track portion are located at a respective second upper and lower distance D1, D2 further away from the seat assembly than an associated virtual continuation of the first upper and lower track portion. As a result, the valve member will be moved against the seat in the closed position. This embodiment is a mechanical inversion which is not shown in the figures. The lower pin cavity 47 has a lower cavity width 72 and a lower cavity length 74, wherein a cross-section of the lower pin has a lower pin width 73 and a lower pin length 75. The lower cavity width 72 matches the lower pin width 73 in that no play between them is present. The lower cavity length 74 is greater than the lower pin length 75, thereby providing said lower play. Likewise, the upper pin cavity has an upper cavity width and an upper cavity length. A cross-section of the upper pin has an upper pin width and an upper pin length, wherein the upper cavity width matches the upper pin width in that no play is present between them. The upper cavity length is greater than the upper pin length thereby providing said upper play. The upper and lower pin cavity have opposing longitudinal sides 77 which define the length of the upper and lower pin cavity. The upper and lower pin have longitudinal sides 78, allowing the upper pin to slide relative to the upper pin cavity and the lower pin to slide relative to the lower pin cavity. When seen in top view a direction of play 47, 48 of the upper and lower pin relative to the upper and lower pin holder is oriented transverse to the bore axis 32, and in particular oriented at an angle of 80-100 degrees to the bore axis, more in particular at right angles to the bore axis. The first and second upper follower 52A, 52B are formed on an outer side of the upper pin holder 44 and wherein the first and second lower follower 53A, 53B are formed on an outer side of the lower pin holder 45. The upper and lower cam track 50, 51 are located outwardly of respectively the upper and lower pin holder.  The valve member 28 rotates about a valve member rotation axis 68 which extends between:an upper center of the one of the upper pin and upper pin cavity holder which is connected to the upper side of the valve member, anda lower center of the one of the lower pin and lower pin cavity holder which is connected to lower side of the valve member,wherein the upper and lower play 48, 49 allow a movement of the valve member rotation axis 68 of the valve member relative to the spindle axis 67, such that:in the open position of the valve member, the valve member rotation axis is aligned with the spindle axis, andin the closed position of the valve member, the valve member rotation axis is located at a distance from the spindle axis, wherein the valve member rotation axis is located closer to the seat assembly than the spindle axis. The valve member rotation axis 68 is parallel to the spindle axis 67 in the closed position of the valve member, and in particular also in any position of the valve member between the open and closed position. In the open position, the valve member rotation axis 68 and the spindle axis 67 are aligned. When seen in top view, the valve member rotation axis 68 moves along an axis trajectory between an aligned position which is associated with the open position of the valve member, in which aligned position the valve member rotation axis is aligned with the spindle axis, and an off-center position which is associated with the closed position of the valve member, in which the valve member rotation axis is offset from the spindle axis, wherein when seen in top view the off-center position is located on the port axis. The offset distance may be equal to the distance D1 and depends on the size of the valve.The valve member comprises an annular contact part which is configured to contact the seat assembly in the closed position of the valve member. The contact part may be integral with the valve member and simply be a part of the valve member. A rotation of the spindle 33 causes a same rotation of the valve member 28 over the entire range of rotation of the spindle between the open and the closed position, such that the valve member does not rotate relative to the spindle. Turning to fig. 17, the valve member is shown in its closed position. The valve member 28 engages the seat assembly 60, which will be explained in more detail below. The valve member rotation axis 68 is offset with respect to the spindle axis 67. Turning to fig. 18, the valve member 28 is shown in its open position. The valve member 28 does not engage the seat assembly 60. The bore axis 32 is aligned with the port axis 71. The valve member rotation axis 68 is aligned with the spindle axis 67. Turning to figures 19, 20 and 21, the position of the lower followers 53, pin, pin holder is shown again in respectively the almost closed position, closed position and open position.  NON-CONTACT VALVE WITH DOUBLE PISTON SEATTurning to figures 22 through 25, the housing 12 comprises a downstream seat stop 80 and an upstream seat stop 81. The upstream and downstream seat stop extend circumferentially around the seat.It is noted that the valve 10 can be used as a bi-directional valve. The terms upstream and downstream are used to indicate relative positions, but do not limit the valve to a single direction of flow. For easy assembly of the seat assembly 60 in the housing, a separate housing ring 90 is used which placed after the seat assembly has been installed. The seat assembly 60 comprises a seat ring 85 defining a seat opening 96, wherein the seat ring is movably arranged in the housing 12. The seat ring is movable between un upstream seat position in which the seat ring abuts the upstream seat stop and a downstream seat position in which the seat ring abuts the downstream seat stop. The housing ring 90 allows the installation of the seat assembly from the outside. First the seat ring 85 is positioned in place and next the housing ring 90 is installed. In other embodiments, the installation of the seat assembly may take place from the inside and then a housing ring 90 is not required. Instead, a similar provision which locks the seat assembly in place is then present on the inside. This may for instance be a ring which forms the upstream seat stop 81. During assembly, the seat ring 85 is first installed from the inside and subsequently the ring which forms the upstream seat stop 81 is installed, also from the inside. In this way the seat ring 85 is correctly installed. The housing ring 90 may then be integral with the housing and is considered to form part of the housing 12. Figure 22 shows the valve assembly in the almost closed position and figure 23 shows the valve assembly in the closed position. It is noted that in the shown embodiment the upstream seat stop 81 is formed by the housing and is located upstream of the seat ring 85. However, the upstream seat stop 81 may also be formed by or in the housing ring 90, for instance as an inward protrusion of the housing ring 90. The inward protrusion may interact with a recess in the seat ring 85. Alternatively, the upstream seat stop may be recess in the housing ring 90 and the seat ring 85 may comprise a protrusion which interacts with said recess. Such a protrusion may not be integral with the seat ring 85 but may be connected to it by a screw or bolt or other type of connection.Various embodiments are possible. Hence, the upstream seat stop 81 need not necessarily be located upstream of the seat ring 85. What is important is that the upstream seat stop 81 forms a stop which stops the seat ring from moving further in an upstream direction beyond the upstream seat stop 81. Also, in the shown embodiment the upstream and downstream seat stop extend circumferentially around the seat but embodiments of the upstream and downstream seat stop which are intermittent, i.e. which extend only over a portion of the circumference, are also conceivable. All these embodiments are covered by the terms ‘upstream seat stop’ and ‘an upstream seat position in which the seat ring abuts the upstream seat stop’. Similarly, for the downstream seat stop various embodiments which are different than the shownn embodiments are conceivable. The seat assembly comprises a seat member 82, integral with or connected to the seat ring 85, the seat member being engaged by the movable valve member 28 in the closed position thereof. The seat member is an annular metal insert, but a different design is possible.The seat assembly comprises a number of biasing members 83, which are in particular springs, and which exert a force on the seat ring in an upstream direction, The seat assembly 60 comprises a double piston mechanism 84 comprising:a seal cavity 105 defined between the seat ring and the housing, the seal cavity being limited on a downstream end thereof by a downstream cavity stop 86 formed by the housing and limited on an upstream end thereof by an upstream cavity stop 87 formed by the seat ring,a seal located 88 in the seal cavity, wherein the seal is movable relative to the seat ring between the downstream and upstream cavity stop,an upstream channel 89 (indicated in dashed lines) which extends from an upstream side of the seat assembly to the seal cavity 105,a downstream channel 91 (indicated in dashed lines) which extends from a downstream side of the seat assembly to the seal cavity 105.The seal cavity 105 is formed by an L-shaped portion in an outer circumference of the seat ring 85 and by an opposed L-shaped portion in the housing 12. The seal 88 is annular and may in particular be an O-ring, but may also be a different kind of seal, such as a graphite seal or a different kind of seal, depending on the application and the operating conditions, such as temperature and medium. Other seals may also be possible.Turning specifically to fig. 25, when the valve member 28 is in the closed position and a downstream fluid pressure is higher than an upstream fluid pressure, the seal 88 moves against the upstream cavity stop 87 and a net force is created on the seat ring 85 which presses the seat member 82 against the valve member. When the valve member 28 is in the closed position and an upstream fluid pressure is higher than a downstream fluid pressure, the seal 88 moves against the downstream cavity stop 86 and a net force is created on the seat ring 85 which presses the seat member 82 against the valve member. Hence, when the valve member 28 is in the closed position the seat member 82 is pressed against the valve member both when a positive and negative pressure difference exists between the upstream and downstream side. The downstream cavity stop 86 is formed on the housing ring 90 which for this purpose is considered part of the housing 12.Returning to fig. 24, when the valve member is in the open position, the seat ring 85 is pressed against the upstream seat stop 81 by the biasing members 83. The upstream channel 89 is closed. The downstream fluid pressure press the seal 88 against the upstream cavity stop 87 and assists in pressing the seat ring 85 against the upstream seat stop 81.The non-contact mechanism 100 which is described above causes the valve member to:have a component of movement in the direction of the port axis and toward the seat member in a final portion of a movement of the valve member from the open position to the closed position thereof and,have a component of movement in the direction of the port axis and away from the seat member in an initial portion of a movement of the valve member from the closed position thereof to the open position,wherein the non-contact mechanism 100 prevents the valve member 28 from sliding against the seat member 82 during the final portion respectively initial portion of movement, andwherein when the valve member 28 is in the open position the seat ring is pressed against the upstream seat stop 81 by the biasing members. The seat assembly with the upstream seat stop 81 and the downstream seat stop 80 can be used with the present non-contact mechanism 100 but can also be used in combination with existing ball valves having a different non-contact mechanism, such as the rising stem ball valve configured to be moved up and down in order to move the valve member between the open and closed position.Hence, the non-contact mechanism may be:a rising stem mechanism which converts a part of a linear movement of stem into a rotation of the valve member and converts a part of a linear movement of a stem into a tilting of the valve member toward or away from the seat, e.g. as disclosed in US3515371A or US11549595B2, ora non-contact mechanism having a coupling between the spindle and the valve member, wherein the coupling converts a first portion of a rotation of the spindle into a rotation of the valve member and converts a second portion of a rotation of the spindle into a displacement of the valve member toward or away from the seat, e.g. as disclosed in WO2019 / 229265A1, ora non-contact mechanism comprising a valve member having a main body and valve plates which are movable relative to the main body, e.g. as disclosed in GB338913A, ora non-contact mechanism 100 as claimed in any of claims 11-31.The seat ring 85 can make a stroke between the upstream seat stop 81 and the downstream seat stop 80. The stroke has a stroke length which depends on the size of the valve.The upstream channel 89 is defined between the seat ring 85 and the housing 12, and the downstream channel 91 is defined between the seat ring 85 and the housing 12. The upstream channel and / or downstream channel extend circumferentially around the seat ring 85.In the open position of the valve member, the bore axis 32 may be substantially aligned with a port axis 71 extending through respective centers of the first and second port. In the closed position of the valve member 28, the bore axis 32 may be transverse to the port axis 71. The valve member stays vertically upright and does not tilt during the rotation between the open and closed position thereof. The spindle, valve member, upper and lower couplings and the upper and lower cam tracks and followers form a non-sliding mechanism which prevents the valve member from sliding along the seat. An advantage of the present invention is that the valve can act as a non-contact, bidirectional valve with only one seat. In other words, the valve works regardless of the direction of flow of the fluid through the valve. This is due to the fact that the seat is pressed against the valve member regardless the direction of flow. The valve member of the present invention may be used with any fluid, gas or liquid. Examples may be oil, water, air, all kinds of chemicals. In some embodiments, the second and third lower track portion and / or the second and third upper track portion may be opposite sides of a slot-type cam track as shown in fig. 26.As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the invention. The terms "a" or "an", as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and / or having, as used herein, are defined as comprising (i.e., open language, not excluding other elements or steps). Any reference signs in the claims should not be construed as limiting the scope of the claims or the invention. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. 

Claims

1. Valve (10), comprising:a housing (12), comprising:a first port (14), anda second port (16), wherein the housing comprises a chamber (18) which defines an inner volume (V) between the first and second port,a movable valve member (28) positioned in the housing, wherein the valve member has a channel bore (30) which defines a bore axis (32), wherein the valve member is rotatable between an open position and a closed position, a seat (60) associated with the first or second port, wherein the seat is engaged by the movable valve member in the closed position thereof, a spindle (33) configured to be rotated by an operating device such as a hand-held lever or an actuator (26) in order to rotate the valve member between the open position and the closed position,an upper coupling (40) between the spindle (33) and the valve member, the upper coupling being configured to transfer the rotary movement of the spindle to the valve member, wherein the upper coupling comprises an upper pin (42) and an upper pin holder (44) which defines an upper pin cavity (46), wherein one of the upper pin and upper pin holder is connected to an upper side of the valve member and the other one is connected to the spindle, wherein the upper pin is accommodated in the upper pin cavity, wherein upper play in a direction transverse to the bore axis is present between the upper pin and the upper pin cavity, which upper play allows the valve member to move relative to the spindle in said direction transverse to the bore axis,a lower coupling (41) between the valve member and the housing, the lower coupling being configured to allow the valve member to rotate relative to the housing, wherein the lower coupling comprises a lower pin (43) and a lower pin holder (45) which defines a lower pin cavity (47), wherein one of the lower pin and lower pin holder is connected to a lower side of the valve member and the other one is connected to the housing, the lower pin being accommodated in the lower pin cavity, wherein lower play in a direction transverse to the bore axis is present between the lower pin and the lower pin cavity, which lower play allows the valve member to move relative to the housing in the direction transverse to the bore axis,an upper cam track (50) and at least one upper follower (52) which are located at an upper side of the valve member, wherein one of the upper cam track and upper follower is connected to an upper side of the housing, the other one being connected to an upper side of the valve member, wherein the upper follower is configured to move along the upper cam track during rotation of the valve member,a lower cam track (51) and at least one lower follower (53) which are located at a lower side of the valve member, wherein one of the lower cam track (51) and the lower follower is connected to a lower side of the housing, the other one being connected to a lower side of the valve member, wherein the lower follower is configured to move along the lower cam track during rotation of the valve member,wherein the upper cam track and upper follower and the lower cam track and lower follower are configured to move the valve member toward and against the seat in a final portion of the rotation from the open position to the closed position, and wherein the upper and lower cam track and the upper and lower follower are configured to move the valve member away from the seat in an initial portion of the rotation from the closed position to the open position.

2. Valve according to the preceding claim, wherein when seen in top view, the upper cam track comprises:a first upper track portion (62) which has the shape of a part of a circle and has a first upper radius (R1), a second upper track portion (64) which has a different shape than the first upper track portion and is configured to push the at least one upper follower toward the seat when the valve member approaches the closed position,a third upper track portion (66) which has a different shape than the first upper track portion and is configured to push the at least one upper follower away from the seat when the valve member just leaves the closed position,and wherein the lower cam track comprises:a first lower track portion (61) which has the shape of a part of a circle and has a first lower radius (R1), a second lower track portion (63) which has a different shape than the first lower track portion and is configured to push the at least one lower follower toward the seat when the valve member approaches the closed position,a third lower track portion (65) which has a different shape than the first lower track portion and is configured to push the at least one lower follower away from the seat when the valve member just leaves the closed position,wherein optionally:in case the cam tracks are connected to the housing, the second upper and lower track portion - when seen in top view - are located at a respective first upper and lower distance (D1, D1) closer to the seat than an associated virtual continuation (69) of the first upper and lower track portion, and wherein when seen in top view the third upper and lower track portion are located at a respective second upper and lower distance (D2, D2) closer to the seat than an associated virtual continuation (69) of the first upper and lower track portion, andin case the cam tracks are connected to the valve member, the second upper and lower track portion - when seen in top view and when the valve member is in the closed position - are located at a respective first upper and lower distance further away from the seat than an associated virtual continuation (69) of the first upper and lower track portion, and the third upper and lower track portion are located at a respective second upper and lower distance further away from the seat than an associated virtual continuation (69) of the first upper and lower track portion,Wherein optionally a port axis (71) is defined by centers (C1, C2) of the first and second ports, wherein when seen in top view the first upper and lower distance (D1, D1) increase with a decreasing distance (D3) between the at least one follower (53A) and the port axis.

3. Valve according to any of the preceding claims, wherein when the at least one upper and lower follower move along respectively the second upper and lower track portion, the valve member moves toward the seat while rotating from the open to the closed position and wherein when the at least one upper and lower follower move along respectively the third upper and lower track portion, the valve member moves away from the seat while rotating from the closed to the open position.

4. Valve according to any of the preceding claims, wherein the one of the lower pin and lower pin holder which is connected to the housing, is rotatably connected to the housing.

5. Valve according to any of the preceding claims, wherein the upper and lower cam track are connected to the housing and wherein the at least one upper and lower followers are connected to the valve member, wherein the valve comprises two lower followers (53A, 53B) which are rounded projections from a circumferential outer wall of the lower pin holder (45) and wherein the valve comprises two upper followers (52A, 52B) which are rounded projections from a circumferential outer wall of the upper pin holder (44).

6. Valve according to any of the preceding claims, wherein the upper and lower pin holder (44,45) are connected to the valve member, wherein the upper pin (42) is connected to the spindle (33) and the lower pin (43) is rotatably connected to the housing (12).

7. Valve according to any of the preceding claims, wherein the valve member comprises a valve member rotation axis (68) which extends between:an upper center of the one of the upper pin and upper pin cavity holder which is connected to the upper side of the valve member and a lower center of the one of the lower pin and lower pin cavity holder which is connected to lower side of the valve member,wherein the upper and lower play allow a movement of the valve member rotation axis of the valve member relative to the spindle axis (67), such that:in the open position of the valve member, the valve member rotation axis is aligned with the spindle axis, and in the closed position of the valve member, the valve member rotation axis is located at a distance from the spindle axis, wherein the valve member rotation axis is located closer to the seat, wherein optionally the valve member rotation axis is parallel to the spindle axis in the closed position of the valve member, and in particular also in any position of the valve member between the open and closed position.

8. Valve according to any of the preceding claims, wherein when seen in top view the valve member rotation axis (68) moves along an axis trajectory between an aligned position which is associated with the open position of the valve member and an off-center position which is associated with the closed position of the valve member, wherein when seen in top view the off-center position is located on the port axis.

9. Valve according to any of the preceding claims, wherein the upper pin cavity has an upper cavity width and an upper cavity length, wherein a cross-section of the upper pin has an upper pin width and an upper pin length, wherein the upper cavity width matches the upper pin width in that no play is present between them and wherein the upper cavity length is greater than the upper pin length thereby providing said upper play, andwherein the lower pin cavity has a lower cavity width (72) and a lower cavity length (74), wherein a cross-section of the lower pin has a lower pin width (73) and a lower pin length (75), wherein the lower cavity width matches the lower pin width in that no play between them is present and wherein the lower cavity length is greater than the lower pin length, thereby providing said lower play, andwherein the upper and lower pin cavity have opposing longitudinal sides which define the length of the upper and lower pin cavity, and wherein the upper and lower pin have longitudinal sides, allowing the upper pin to slide relative to the upper pin cavity and the lower pin to slide relative to the lower pin cavity.

10. Valve (10), comprising:a housing (12), comprising:a first port (14), anda second port (16), wherein the housing comprises a chamber (18) which defines an inner volume (V) between the first and second port,a movable valve member (28) positioned in the housing, wherein the valve member has a channel bore (30) which defines a bore axis (32), wherein the valve member is rotatable about a valve member rotation axis (68) between an open position and a closed position, a seat (60) associated with the first or second port, wherein the seat is engaged by the movable valve member in the closed position thereof, a spindle (33) configured to be rotated about a spindle axis (67) by an operating device such as a hand-held lever or an actuator (26) in order to rotate the valve member between the open position and the closed position,a first coupling (40) between the spindle (33) and the valve member, the first coupling being configured to transfer the rotary movement of the spindle to the valve member, wherein the first coupling allows the valve member to move relative to the spindle over a distance in a direction transverse to the bore axis and transverse to the valve member rotation axis, and a first cam track (50) and at least one first follower (52), wherein one of the first cam track and first follower is connected to the housing, the other one being connected to the valve member, wherein the first follower is configured to move along the first cam track during rotation of the valve member,wherein the first cam track and the at least one first follower are configured to move the valve member toward and against the seat in a final portion of the rotation of the valve member from the open position to the closed position, and wherein the first track and the first follower are configured to move the valve member away from the seat in an initial portion of the rotation of the valve member from the closed position to the open position.

11. Valve (10) according to the preceding claim, comprising a second cam track (51) and at least one second follower (53), wherein the second cam track and second follower are positioned at a distance in the direction of the valve member rotation axis (68) from the first cam track and first follower, wherein one of the second cam track (51) and the second follower is connected to the housing, the other one being connected to the valve member, wherein the second follower is configured to move along the second cam track during rotation of the valve member,wherein the first cam track and first follower and the second cam track and second follower are configured to move the valve member toward and against the seat in a final portion of the rotation from the open position to the closed position, and wherein the first and second cam track and the first and second follower are configured to move the valve member away from the seat in an initial portion of the rotation from the closed position to the open position.

12. Valve (10) according to any of claim 10-11, wherein the first coupling between the spindle (33) and the valve member is an upper coupling (40), wherein the upper coupling comprises an upper pin (42) and an upper pin holder (44) which defines an upper pin cavity (46), wherein one of the upper pin and upper pin holder is connected to an upper side of the valve member and the other one is connected to the spindle, wherein the upper pin is accommodated in the upper pin cavity, wherein upper play in a direction transverse to the bore axis is present between the upper pin and the upper pin cavity, which upper play allows the valve member to move relative to the spindle in said direction transverse to the bore axis,  or wherein the first coupling comprises a track and traveller, the track connected to the spindle and the traveller connected to the valve member or vice versa, wherein the track extends in a direction transverse to the bore axis and transverse to the valve member rotation axis.

13. Valve (10) according to any of claims 10-12, comprising a second coupling (41) between the valve member and the housing or between the valve member and the spindle, the second coupling being configured to allow the valve member to rotate relative to the housing, wherein the second coupling allows the valve member to move relative to the housing in the direction transverse to the bore axis and transverse to the valve member rotation axis.

14. Valve (10) according to any of claim 10-13, wherein the second coupling is a lower coupling (41) between the valve member and the housing, the lower coupling being configured to allow the valve member to rotate relative to the housing, wherein the lower coupling comprises a lower pin (43) and a lower pin holder (45) which defines a lower pin cavity (47), wherein one of the lower pin and lower pin holder is connected to a lower side of the valve member and the other one is connected to the housing, the lower pin being accommodated in the lower pin cavity, wherein lower play in a direction transverse to the bore axis is present between the lower pin and the lower pin cavity, which lower play allows the valve member to move relative to the housing in the direction transverse to the bore axis, or wherein the second coupling comprises a track and traveller, the track connected to the housing and the traveller connected to the valve member or vice versa, wherein the track extends in a direction transverse to the bore axis and transverse to the valve member rotation axis.

15. Valve (10) according to any of claims 10-14, wherein the first cam track is an upper cam track (50) and the first follower is an upper follower (52) which are located at an upper side of the valve member, wherein one of the upper cam track and upper follower is connected to an upper side of the housing, the other one being connected to an upper side of the valve member, wherein the upper follower is configured to move along the upper cam track during rotation of the valve member,wherein the second cam track is a lower cam track (51) and wherein the second fllower is a lower follower (53) which are located at a lower side of the valve member, wherein one of the lower cam track (51) and the lower follower is connected to a lower side of the housing, the other one being connected to a lower side of the valve member, wherein the lower follower is configured to move along the lower cam track during rotation of the valve member.

16. Valve according to any of claims 10-15, wherein when seen in top view, the first, upper cam track comprises:a first upper track portion (62) which has the shape of a part of a circle and has a first upper radius (R1), a second upper track portion (64) which has a different shape than the first upper track portion and is configured to push the at least one upper follower toward the seat when the valve member approaches the closed position,a third upper track portion (66) which has a different shape than the first upper track portion and is configured to push the at least one upper follower away from the seat when the valve member just leaves the closed position,and wherein the second, lower cam track comprises:a first lower track portion (61) which has the shape of a part of a circle and has a first lower radius (R1), a second lower track portion (63) which has a different shape than the first lower track portion and is configured to push the at least one lower follower toward the seat when the valve member approaches the closed position,a third lower track portion (65) which has a different shape than the first lower track portion and is configured to push the at least one lower follower away from the seat when the valve member just leaves the closed position,wherein optionally:in case the cam tracks are connected to the housing, the second upper and lower track portion - when seen in top view - are located at a respective first upper and lower distance (D1, D1) closer to the seat than an associated virtual continuation (69) of the first upper and lower track portion, and wherein when seen in top view the third upper and lower track portion are located at a respective second upper and lower distance (D2, D2) closer to the seat than an associated virtual continuation (69) of the first upper and lower track portion, andin case the cam tracks are connected to the valve member, the second upper and lower track portion - when seen in top view and when the valve member is in the closed position - are located at a respective first upper and lower distance further away from the seat than an associated virtual continuation (69) of the first upper and lower track portion, and the third upper and lower track portion are located at a respective second upper and lower distance further away from the seat than an associated virtual continuation (69) of the first upper and lower track portion, wherein optionally a port axis (71) is defined by centers (C1, C2) of the first and second ports, wherein when seen in top view the first upper and lower distance (D1, D1) increase with a decreasing distance (D3) between the at least one follower (53A) and the port axis.

17. Valve according to any of the preceding claims 10-16, wherein when the first and second upper and lower follower move along respectively the second upper and lower track portion, the valve member moves toward the seat while rotating from the open to the closed position and wherein when the at least one upper and lower follower move along respectively the third upper and lower track portion, the valve member moves away from the seat while rotating from the closed to the open position.

18. Valve according to any of the preceding claims 10-17, wherein the one of the lower pin and lower pin holder which is connected to the housing, is rotatably connected to the housing.

19. Valve according to any of the preceding claims 10-18, wherein the first, upper cam track and second, lower cam track are connected to the housing and wherein the at least one first, upper followers and second, lower followers are connected to the valve member, wherein the valve comprises two lower followers (53A, 53B) which are in particular rounded projections from a circumferential outer wall of the lower pin holder (45) and wherein the valve comprises two upper followers (52A, 52B) which are rounded projections from a circumferential outer wall of the upper pin holder (44).

20. Valve according to any of the preceding claims 10-19, wherein the upper and lower pin holder (44,45) are connected to the valve member, wherein the upper pin (42) is connected to the spindle (33) and the lower pin (43) is rotatably connected to the housing (12).  

Images