Regulating valve

A regulating valve for flow control of a medium in a heating or cooling system includes a valve body including an inlet connection, an outlet connection, and a valve neck in which a valve seat and a flow through opening are provided. In the valve neck, a complete valve trim and a valve hand wheel are provided. The valve body includes a first cone to determine the preset (Kvs-value) of the maximal flow through the complete regulating valve. The first cone has at least one opening for flowing through of the medium, where the design of the opening determines the regulating characteristic of the complete regulating valve, and where the Kvs-value of the valve is changed continuously, with maintained regulating characteristic. The first cone is arranged continuously, axially displaceable relative the valve seat, whereby selected parts of the opening of the first cone are shielded by the valve seat.

TECHNICAL FIELD

Present invention relates to a device for regulation the flow output of a medium in a heating or cooling system and where the device is a regulating valve with maintained regulation characteristics at different Kvs-values in one and the same valve.

BACKGROUND ART

Background Art and Technical Problem

Generally known in flow regulation is regulation valves with a regulating characteristic denoted EQ (equal percentage) and also EQM (equal percentage modified). The aim with those techniques is to provide a logarithmic characteristic where the flow through the regulating valve is regulated in a way that a flow is obtained and an output power coming from the system at for example 50% when the cone of the regulating valve is raised up to 50% if its total hub. Optimally this will be achieved irrespective of at which maximal flow the valve is set to, i.e. which maximal Kv-value, denoted Kvs-value, is selected. Valves where the Kvs-value can be set differ from traditional regulating valves, just by this feature and they are denoted preset regulating valves.

There are known solutions with regulating valves with EQM-functions and variable Kvs-value, but in most of those solutions limitations in the regulating function of the valve are introduced where the Kvs-value is connected with the range of lift of the valve, its hub. This limitation leads to that the regulation is impaired because, for some Kvs-values, only a small part of the hub remains for the regulation. The most existing preset able regulating valves are impaired just with that disadvantage, that the range of lift is limited when the valve is preset. One step to improvement of the function is taken by the solution that is disclosed in US 20090199905 A1, where one and the same valve has this EQ/EQM-function and where the characteristic is maintained by changing the maximal flow, the Kvs-value.

Those advantageous functions is accordingly found in older solutions, but principally the function to maintain the characteristic is solved by that several valves are connected in series, which means that the regulating function, the throttling that is crucial for the flow limitation, isn't totally dominating for the change of flow. To secure an optimal flow limitation according to the characteristic of the regulation the construction must be based on only one throttling location.

In earlier solutions there are also problems with sealing against flow leakages in and around the cones of the valves or the flow limiting parts. A lot of solutions are also sensitive for tolerances and demands a high grade of accuracy at the manufacturing of and fitting in the included parts, which has led to that different seals are used to minimize those leakages. The leakages will be particularly problematic at low flows, where the desired flow is small. The influence of a leakage flow will in those operational cases be devastating.

DISCLOSURE OF INVENTION

Summary of the Invention

By the present invention a preset able regulating valve is achieved and the problem with manufacturing tolerances and seals is solved by that the construction is made in a new way that minimize the leakage flows and its effect on the characteristic, at the same time as the valve has the advantageous features with adjustable Kvs-value with maintained regulation characteristic and regulation with full hub irrespective of the preset Kvs-value. In addition the invention has the advantage that the throttling is based on only one throttling location.

The complete regulating valve comprises in a preferred embodiment of the invention a valve body, with an inlet connection and an outlet connection, and to the valve body a valve neck is connected and connections for the measuring nipples. In the valve neck a complete valve trim is provided comprising an upper piece and at the top of the valve neck a valve hand wheel is provided. Through the valve hand wheel and the valve trim a so called shaft is provided, which is an axle that is coordinated with one at the regulating valve mounted actuator for motorizing the regulation function by the valve. Around this valve shaft preferable a return spring is found. In addition the lower part of the valve neck comprises a flow through opening where the medium can flow through the valve, from the inlet connection to the outlet connection. In the bottom of the valve neck in connection with the flow through opening a valve seat is provided.

The presetting of the Kvs-value, i.e. the selection of a desired maximal flow by the actual operational case is solved by that a, preferable sleeve shaped, cylindrical first cone is arranged axially displaceable relative the valve seat. The first cone comprises an opening for a flow through of the fluid flow and the shape of this opening determines the regulation characteristic for the valve to work. The first cone is continuously, axially displaceable in the valve neck and when the cone is displaced relative the valve seat, in direction to or from the valve seat, the opening of the cone is shielded or opened relative the valve seat in different extent and this irrespective of which preset that is whished, i.e. irrespective of which Kvs-value that is selected. The length of movement of the first cone for the presetting, i.e. the length that the cone can be moved by the presetting is the preset length of the complete regulating valve. The invention is not restricted only to have the above said EQ/EQM-characteristic, also the shape of the opening of the first cone determines the regulation characteristic and this characteristic can for example be linear or any other desired characteristic. In the new construction the number of seals is minimized at the same time as the location of the seals that still must be provided because of the moving parts, is favorable and admits selection of sealing materials that are durable over the length of life of the valve.

Furthermore a preferred embodiment of the invention comprises a second cone that preferable is sleeve shaped, and cylindrical and surrounds at least partly the outer surface of the first cone, preferable its upper, farther part, relative the valve seat. By that way of arrangement it is possible to let the opening of the first cone be shielded by the second cone, as far as is desired, by the presetting. The cylindrical shape of the first and the second cone is advantageous by eventual sealing of the leakage flow between the surfaces of the cones opposite each other. The second cone gives additionally advantages by the presetting, which is described above, by that the window, which is formed for the flowing through of the medium, and which according to the first form of execution is limited by the valve seat and the opening of the first cone, also can be limited to selected parts by means of the second cone. This means that it is made possible to select presetting, i.e. expose selected parts of the opening of the first cone for flowing through of the medium to the flow through opening of the valve. In addition the second cone is axially displaceable in the valve body and its valve neck, between a first farther end position relative the valve seat and a second end position in connection to the valve seat. By this, advantages are obtained, compared to older solutions, in a way that additionally functions can be added to the valve, such as regulation and closing functions.

A preferred embodiment of the invention is that the first cone is arranged to regulate the flow through the complete valve in a regulation position, i.e. by a certain operational case. The regulating valve is usually controlled by a mounted actuator, which via any kind of sensor detects a changing in the load/power output in the fluid system where the valve is working. This actuator cooperates with the shaft of the valve, which is the axle that in a regulating valve normally connects the regulating cone with the mounted actuator. When a changing in need or flow, is indicated the shaft is moved according to the invention, axially influenced by the actuator, whereby the movement of the shaft is transmitted to the first and the second cone, which in the regulation position are locked relative each other in the position that is given by the presetting. Since the shaft is fixed arranged with a shut off screw, which in turn is joined with a preset screw, preferable via a thread joint, and that the second cone is axially locked to the preset screw, preferable by a nut and additionally, that also the first cone is axially locked to the preset screw, preferable by a thread joint, both the first and the second cones are accordingly moved at the same time axially influenced by the shaft. The flow through the complete regulating valve is determined by the position of the first cone, with its opening, relative the shielding against the valve seat, and this flow corresponds to the load/power output that exists I every individual operational case. Thus, the flow through the complete regulating valve is variable from 0-100% of the wished maximal flow, the selected Ksv-value, i.e., that for the first and the second cone the entire hub is available irrespective of the setting of the preset in the valve. The position of the second cone relative the first cone is not changed during the regulation, but their mutual position is the same, given by the presetting.

According to a further preferred embodiment of the invention the first cone is axially displaceable relative the second cone. In that way conditions are created for both cones to work either coordinated or individual to provide the desired functions as for example presetting or alternatively shutting off, by that both of the two cones can be brought to different positions relative each other. One advantage with this is for example that in the preferred embodiment the presetting is made from the Kvs-value of the valve, i.e. the movement of the first cone axially and in direction towards or away from the valve seat without influencing the position of the second cone. After performed presetting, when the valve works in its normal/regulating position the position of the second cone along/around the first cone is locked in its selected preset position, via a thread joint according to the above description, and the regulation is made without that the second cones shielding of the opening of the first cone is changed.

In a preferred embodiment of the invention a preset of the valve, i.e. the movement of the first cone to an intended position relative the valve seat, occurs in a way that desired Kvs-value is obtained, by a rotary motion of the valve hand wheel. By that the valve hand wheel indirect via parts in between, is engaged with a preset screw, preferable at its outside, the movement of the valve hand wheel is transmitted to this screw. The preset screw in turn is threaded inside, where the thread surrounds the upper part of the first cone, which upper part also is provided with threads. In this way the rotary motion is transmitted via the threaded joint to the first cone, which is moved axially, to desired position somewhere between its outer positions, indicating max Kv and min Kv. The moment of presetting is in older solutions made with some form of special tools, while this in the now present invention is performed by means of a valve hand wheel.

According to one preferred embodiment of the invention the hub of the complete regulating valve is determined by the movement of the second cone between its end positions, the first farther end position relative the valve seat and the second end position in connection to the valve seat. The movement of the second cone between those end positions is at least equal to the height of the flowing through opening in the valve body. Consequently the second cone doesn't limit and shield the opening of the flow through opening in the farther position of the second cone.

According to a preferred embodiment of the invention the first cone works by regulation with fully hub, irrespective of selected maximal flow through the valve. This means that ir-respective of selected Kvs-value, which is selected in the presetting position, the regulations accuracy is maximal and not as in older solutions where the hub where limited different depending on how the Kvs-value was selected, which implied a limiting of the regulating area. In this new construction a good regulating accuracy is obtained for every preset at the same time as the regulation characteristic is maintained. This is made possible by that the height of the opening in the first cone is at least equal to the sum of the height of the flow through opening in the valve body and the preset length.

According to a preferred embodiment of the invention the height of the flow through opening in the valve body is not affected at all of the presetting of the valve. In the pre set position the second cone is always in its first farther position relative the valve seat and in this position the second cone doesn't shields the flow through opening. In addition, according to the above, the height at the opening of the first cone is larger than the height of the flow through opening and the first cone is arranged so that this height in no way, irrespective of the preset position by the first cone, shields any part of the height of the flow through opening. This means that after the presetting is performed, i.e. in the regulation position of the valve, the entire hub is always accessible, which results in the above described advantages.

According to a further preferred embodiment of the invention the second cone is rotary locked relative the valve neck by that a so called signal ring is provided around the periphery of the second cone and this signal ring includes a raising, a ridge, which preferable has a elongated extension in axial direction along the periphery of the signal ring, and which ridge constitute a raising on both the outer and the inner side of the signal ring. The elongated ridge is inwards, towards the second cone, arranged to be engaged with a groove on the periphery of the second cone whereby the signal ring will be arranged rotary locked around the second cone. Additionally the ridge of the signal ring is outwards, relative the second cone, arranged to run in a groove in the valve neck of the valve body, which groove runs in axial direction relative the second cone and the groove is at least as long as the hub of the valve. Thus the second cone cannot rotate in the valve body but is on the contrary displaceable in axial direction at least as far as the hub of the valve. The rotary locking is necessary for the all in all function of the valve, and the advantage is that the sealing between the first and the second cone and the sealing between the second cone and the valve seat is facilitated when only axial movements between the parts are allowed and consequently the demands on the seal is reduced.

According to a preferred embodiment of the invention the first cone is rotary locked to the second cone by that at least one guide pin is fixed mounted in the second cone and continuous to and through the top of the first cone via a recess in the same. Accordingly the first cone is also indirect rotary locked relative the valve neck. This guide pin is extending in axial direction relative the cones and is formed in a way that the first cone is axially displaceable relative the guide pin and at least to the length that corresponds to the preset length. By that the first cone, with its opening for flowing through of fluid, cannot rotate relative the valve body this opening is by position coordinated with the flow through opening of the valve body and accordingly the opening is in the same position relative to and in flow direction of the complete valve. Thus the pressure drop over the valve relative those solutions where a corresponding cone with its opening is rotated to different positions relative the flow through opening, depending on the preset of the Kvs-value, and the opening in these solutions doesn't always coincide with the flow through opening in the valve body.

Depending on manufacturing tolerances at inherent moving parts there will always come to leakage flows around regulating cones/parts in regulating valves. To minimize those leakage flows it is necessary to control the characteristic of the regulating valve irrespective of the flow through the valve. Especially at small flows a leakage has a considerable influence on the characteristic, according to a preferred embodiment of the invention the sealing of the leakage flow is made around the first cone by that a seal is provided between the first cone and de second cone. The seal is mounted in a groove in the inner surface of the second cone and surrounds so the first outer surface of the first cone and seals the gap that must exists for the mobility of the parts relative each other. This design leads to that the seal is found in a position where the sensitivity to manufacturing tolerances is not so important, and accordingly the need of small tolerances by the manufacturing are reduced and the accuracy in the regulation characteristic will be better.

According to a further preferred embodiment of the invention the complete regulating valve is provided with a shut-off function by that the second cone in its second end position, in connection to the valve seat, totally shields the flow through opening. In the first farther end position of the second cone, relative the valve body, the flow through opening isn't shielded at all. Accordingly a shut off function is also achieved with one and the same valve.

According to a further preferred embodiment of the invention the valve seat comprises a seal, which is provided to seal between the first cone and the valve seat, here also to prevent flow of leakage, which influences the characteristic in a negative way. The seal also has the function to seal against leakage when the valve is fully closed to flow through of fluid, in its shut off position, by that the second cone in its second end position, in connection to the valve seat, is touching the bottom by the seal which leads to that nu fluid can pass the cones. Thus, with one and the same part—the seal of the seat—both a sealing of the leakage at normal operation and together with the second cone a tight shut off position by the complete valve is achieved.

To minimize undesired pressure drop over the complete valve it is advantageously to let fluid flow essentially in parallel with the main flow direction through the complete regulating valve, without considerable deflections of the flowing path. According to a preferred embodiment of the invention the flow through opening for the fluid of the complete regulating valve is hence preferable located in the lower part of the valve body in direct connection to the valve seat and close to the center lines of the inlet connection and the outlet connection and hence close to the main direction for the run through of the complete valve. This minimizing of the flow deflection at the place of throttling leads to minimal turbulence in the flow, resulting in that also the problems with sounds from the location of throttling is reduced which is a known problem in several older solutions.

By the same reason as above, minimizing the pressure drop, turbulence and sound, coincides, according to a preferred embodiment of the invention, the symmetric line by the opening of the first cone mainly with the symmetric line of the flow through opening. According to the above mentioned preferred embodiment the second cone is rotary locked in this position and the first cone is rotary locked to the second cone. The first cone is how-ever axial movable, i.e. in the same direction as the symmetric line of the opening extends, whereby the first opening of the cone also is moved along the symmetric line of the flow through opening and therefore the main flow through of the two openings coincides resulting in a minimal turbulence.

Advantageous Effects

Accordingly, both earlier known advantages together with new advantages in one and the same valve are achieved:A valve where the Kvs-value can vary in one and the same valve body.The characteristic of the valve is the same irrespective of which Kvs-value is set.A good accuracy by the regulation with fully hub by regulation irrespective of the pre-setting, and of the Kvs-value set by the valve.A valve that by the manufacturing is less sensitive to tolerances and deviations in size.A valve where the preset of the Kvs-value can be done irrespective of if an actuator is mounted or not.Thus the valve can be supplied completely with mounted actuator if desired to facilitate and speed up the installation work on place.

The constructive design of the present invention is described in detail below. In addition the prior art is further developed in the field in different aspects. This is realized in the present invention by that a device of the above described kind mainly is constituted in a way that is evident from the characterizing part of claim1. Further characteristics and advantages of the invention is evident from following description related to the attached drawings, showing a preferred, but not limiting example of embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1shows an example of a curve over the fluid flow through the valve as a function of the height of lift by the valve cone for the present invention, at a constant difference pressure over the valve. Exemplified by an assumption that the exothermic device to which the valve regulates the flow, gives 50% of prescribed power when the flow is 20% of the prescribed, will in this case the valve give 20% flow when it is open to 50%. This means that when the valve is open to 50% the power is also 50%. When this relation coincides for all flows the valve has a logarithmic function, or a modified logarithmic characteristic—an EQM-function. The present invention has by this design of the cone, the features that this relationship between height of lift, flow and power is maintained for different Kvs-values, by one and the same valve dimension.

FIG. 2ashows a longitudinal cut through a complete regulating valve1according to a preferred embodiment of the device, comprising a valve body2with a inlet connection3and an outlet connection4, for connection to the tube system in which the complete regulating valve1works. At the valve body2also two connections for measuring nipples8are provided for measuring and eventually detecting the static difference pressure over the regulating valve. The fluid that flows through the regulating valve during operation flows from the inlet side, the inlet connection3, to the outlet side, the outlet connection4, via a flow through opening7with a height H, in connection with a valve seat6, which seat is provided in the lower part28of the valve body. A valve neck5emanates in an angle from the valve body2, a valve trim complete38is provided in the valve neck5. The valve trim complete38comprises a top piece9and a sleeve shaped, cylindrical first cone13, which is axial displaceable arranged in the valve neck5. The lower part of the first cone13, closest to the valve seat6is open for inflow of the medium, and the outflow of the medium from the first cone13occurs through the opening14of the first cone, which is provided at the periphery of the first cone13and in the main direction for the flow through of the medium through the complete regulating valve1. The outer surface of the first cone, preferable at its upper part, is partly surrounded by a sleeve shaped, cylindrical second cone15, which is arranged displaceable in the valve body6. The first cone and the second cone15is additionally displaceable relative each other and between the outer surface of the first cone and the inner surface of the second cone a seal26, preferable in form of an0-ring, is provided.

By that the first and the second cone are displaceable relative each other, it is allowed that presetting of the complete regulating valve1, i.e. the preset of the Kvs-value, the maximal flow that has to flow through the regulating valve, can be done without limiting of the hub. This is a very important feature since the accuracy by the regulation then will be good, irrespectively of selected presetting. By presetting, in the presetting position of the regulating valve, the second cone15will be found in its upper, relative the valve seat farther position. The presetting means that the position/distance of the opening14of the first cone relative the valve seat6is set. By the presetting a valve hand wheel10, provided around the valve neck5, is rotated, which valve hand wheel via teeth is engaged with a rotatable, with teeth provided counter gear30. This counter gear in turn is engaged with a rotatable and with teeth provided so called sol31which in turn is engaged with the preset screw17and accordingly the rotary motion of the valve hand wheel10is transmitted to the preset screw17. This is rotatable but is not moved axially in the valve neck during the presetting.

The lower part of the preset screw17comprises an inner thread which cooperates with an outer thread provided at the upper part of the first cone13and by the rotation of the preset screw17the rotation is transmitted, via the intermediate thread joint20, to an axial movement at the first cone13. Accordingly the first cone is moved axially in direction to or from the valve seat6. It is to be noted that the second cone15is not influenced, but will stay in its upper position by the presetting. Later, when the presetting is finished and the valve is ready to regulate, the mutual position, given by the presetting, between the first and the second cone will not be changed.

By the regulation of the system in which the complete valve1is a part, usually a mounted (not shown) actuator is used to control the regulating valve, which actuator is mounted at the adapter29of the regulating valve. The adapter is replaceable, depending on what kind of actuator is used. The actuator communicates with a detector in the system, and by changed need of flow the actuator acts on a valve shaft11, which is axially displaceable in the valve neck5. The axial movement of the valve shaft11is transmitted to the second cone15by that the shaft is fixed in a screw, denoted shutting off screw16, which screw is displaceable provided in the valve neck5. This shutting off screw16in turn is, in the regulation position, axially fixed arranged to the upper end of a presetting screw17, via a thread joint18, and also the presetting screw17is displaceable provided in the valve neck5. Further the second cone15is fixed arranged to the presetting screw17via a nut19. The lower part of the presetting screw17comprises, which is described above, an inner thread which cooperates with an outer thread provided at the upper part of the first cone and these thread joint20axially locks in the regulation position, the presetting screw17and the first cone to each other. When the valve shaft11is axially moved also the shutting off screw16, the presetting screw17and the first cone13and the second cone15is moved axially in the valve neck5without changing of the mutual positions of the cones relative each other. By the simultaneous axial movement of the first cone13and the second cone15the open area for the flow through of the medium through the opening14of the first cone is changed because the opening14is shielded in different degree by the valve seat6depending on the movement of the fist cone13, whereby the flow through the complete regulating valve1is changed. To secure that the opening14of the first cone always is optimally located relative the flow, the first cone13is rotary locked relative the second cone15by that two guide pins24are fixed arranged in the second cone15and those guide pins extends axially relative the first cone and the second cone15and through two recesses25in the top of the first cone. Those guide pins24has a length that is at least equal to the length L of the presetting, i.e. long enough to allow the presetting, when the first cone13and the second cone14are displaceable relative each other. Around the periphery of the second cone15a signal ring21is provided, and this signal ring comprises a ridge22, which preferable has a longitudinal extension in axial direction along the inner and outer surface of the signal ring21. The longitudinal ridge22is provided to grip in a groove36at the periphery of the second cone whereby the signal ring21is being arranged rotary locked around and relative the second cone15. In addition the ridge22of the signal ring is outwards, relative the second cone15, arranged to run in a groove23in the valve neck5, which is evident from the detail view2b, and where the groove23runs in axial direction relative the second cone15and the groove23is at least as long as the hub of the valve. Thus the second cone is rotary locked relative the valve neck5. The signal ring comprises also a groove37, which runs around the whole of its periphery and which groove is arranged to create a communication between the low pressure side at the valve, after the valve seat6, and one of the connections for the measuring nipples8. The other connection for the measuring nipple8communicates with the high pressure side of the valve, the inlet side.

Around the valve shaft11there is a clamped return spring12with surrounding spring sleeve32. The return spring12sees to that the shaft returns to its upper, farther position (a), relative the valve seat6, so called spring return if the actuator of any reason will be out of voltage. For fixing the parts in the valve trim38and for control a top piece9is provided. The top piece9will be fixed arranged against the valve neck5via one in the valve neck fixed mounted lock33for the top piece, which lock is firmly screwed in the material of the valve neck5by the assembling of the valve. The complete regulating valve1also comprises a position for shutting off the flow through, a shutting off function. By the shut off the valve hand wheel10is rotated, whereby the valve hand wheel via teeth, is engaged with a rotatable counter gear34, provided with teeth, arranged to the function of shutting off. This counter gear in turn is engaged with a rotatable so called sol35, provided with teeth, which sol in turn is engaged with the shut off screw16. Thus by the rotation of the valve hand wheel10the movement is transmitted to the shut off screw16which by the thread joint18, transmit the rotator motion to an axial movement at the presetting screw17. By that this, which is described above, is fixed arranged with the second cone15, the second cone will also be moved axially and accordingly also the first cone. To entirely shut off the valve for flow through, the second cone15is moved axially in direction to the valve seat6until the whole flow through opening7is entirely shielded. In the valve seat6a seat seal is provided to seal against it, against the edge directed to the valve seat on the second cone15by completely shut off. The same seat seal27also seals between the first cone13and the valve seat6, irrespective of the position of the function. The function is also evident fromFIG. 4d, where the second cone is on its way to a closed position, in direction down to the valve seat.

FIG. 2bshows an enlargement of a cut A-A through the second cone with its signal ring and ridge. The signal ring21comprises the longitudinal ridge22, which is arranged to run in a groove23, which runs axially in the valve neck5. The signal ring is mounted rotary locked on the second cone15through the ridge22which cooperate with a groove36at the periphery of the second cone.

FIG. 3shows a transverse cut through a complete regulating valve according to a preferred embodiment of the device. In the figure is clear that the opening14of the first cone has a height that is higher than the height of the flow through opening7, and more exactly a height that is at least equal to the height at the height H of the flow through opening7, plus the length of the presetting movement, the presetting movement L, i.e. L+H. By the moment of presetting, as said before, the second cone15is in its upper, farther position relative the valve body6and in the figure also the first cone13is in its upper position, which corresponds to the maximal Kv-value of the regulating valve, its maximal Kvs-value, with maximal possible flow through. If a lower maximal flow is desired, a lower Kvs-value, the first cone13is moved in above described way in direction to the valve seat6, with its seat seal27, whereby the exposed opening is reduced and accordingly also the possible maximal flow through the valve is reduced. By that the opening14of the first cone has the height L+H, accessible hub is by the regulation still maximal irrespective of selected Kvs-value. The exposed part of the opening14of the first cone is still equal to the height H at the flow through opening7and no limitation of the hub is done even if the presetting is selected to the less Kvs-value of the valve.

The complete regulating valve1also comprises, as the most regulating valves a decimal scale and indicating ring as well as a cover cap (not shown). In addition the first and the second cone is balanced by pressure by recesses25in the second cone15to the cavity above the same and by this the static pressure is at the same order of magnitude on both sides of the moving cones.

FIG. 4ashows the design of the first cone13in detail. The first cone13is sleeve shaped and cylindrical, with an open lower part for inflow of fluid and further the outflow of fluid occurs via the opening14of the first cone. The shape of the opening14of the first cone is calculated and gives the complete valve an EQM-characteristic. In addition the threaded part of the upper part is seen, which cooperate with the lower, inner threaded part of the pre set screw17, which is already described.

FIG. 4bshows the regulating valve in a view from the outlet side, with the first cone23set to maximum preset value, at max Kv-value. In the bottom of the valve body5the flow through opening7is provided and this opening is defined by its sides, upper edge as well as the valve seat6. Behind the flow through opening7the first cone13is seen with its opening14in a position that corresponds to maximal opening, i.e. presetting with maximal Kvs-value, which means largest possible flow. The second cone15is located in its upper position, not seen in the figure.

FIG. 4cshows the regulating valve in a view from the outlet side4, with the first cone set to a position that gives e new Kvs-value, for example ca 50% of maximal preset value. Compared toFIG. 4bthe first cone13inFIG. 4cis moved in direction to the valve seat6whereby the upper part of the opening14of the first cone is exposed and by that a lower Kv-value is set. Still a fully hub is obtained for regulation since the second cone15neither in this position shields the flow through opening7

FIG. 4dshows the regulating valve in a view from the outlet side4, with the second cone15, which partly shields the flow through opening7. The valve has in this figure the same presetting as inFIG. 4c, i.e. ca 50% of maximal preset value. The second cone15blocks in the figure partly the flow through opening7, which has started to be totally shielded by the second cone. By continued rotation of the valve hand wheel (not shown) the second cone will at the end totally shield the flow through opening7and the valve is totally closed for flow through. In this position the seat seal27seals between the lower edge of the second cone15and the valve seat6.

PARTS LIST

7flow through opening

8connection for measuring nipple

10valve hand wheel

14opening of the first cone

16shut off screw

28lower part of the valve body

33lock of the top piece

35sol, shut off

37groove, signal ring

38valve trim complete